[[testing]]
= Testing

[partintro]
--
The adoption of the test-driven-development (TDD) approach to software
development is certainly advocated by the Spring team, and so coverage of Spring's
support for integration testing is covered (alongside best practices for unit testing).
The Spring team has found that the correct use of IoC certainly does make both unit and
integration testing easier (in that the presence of setter methods and appropriate
constructors on classes makes them easier to wire together in a test without having to
set up service locator registries and suchlike)... the chapter dedicated solely to
testing will hopefully convince you of this as well.
--




[[testing-introduction]]
== Introduction to Spring Testing

Testing is an integral part of enterprise software development. This chapter focuses on
the value-add of the IoC principle to <<unit-testing,unit testing>> and on the benefits
of the Spring Framework's support for <<integration-testing,integration testing>>. __(A
thorough treatment of testing in the enterprise is beyond the scope of this reference
manual.)__




[[unit-testing]]
== Unit Testing

Dependency Injection should make your code less dependent on the container than it would
be with traditional Java EE development. The POJOs that make up your application should
be testable in JUnit or TestNG tests, with objects simply instantiated using the `new`
operator, __without Spring or any other container__. You can use <<mock-objects,mock
objects>> (in conjunction with other valuable testing techniques) to test your code in
isolation. If you follow the architecture recommendations for Spring, the resulting
clean layering and componentization of your codebase will facilitate easier unit
testing. For example, you can test service layer objects by stubbing or mocking DAO or
Repository interfaces, without needing to access persistent data while running unit
tests.

True unit tests typically run extremely quickly, as there is no runtime infrastructure
to set up. Emphasizing true unit tests as part of your development methodology will
boost your productivity. You may not need this section of the testing chapter to help
you write effective unit tests for your IoC-based applications. For certain unit testing
scenarios, however, the Spring Framework provides the following mock objects and testing
support classes.



[[mock-objects]]
=== Mock Objects


[[mock-objects-env]]
==== Environment

The `org.springframework.mock.env` package contains mock implementations of the
`Environment` and `PropertySource` abstractions (see <<beans-definition-profiles>>
and <<beans-property-source-abstraction>>). `MockEnvironment` and
`MockPropertySource` are useful for developing __out-of-container__ tests for code that
depends on environment-specific properties.


[[mock-objects-jndi]]
==== JNDI

The `org.springframework.mock.jndi` package contains an implementation of the JNDI SPI,
which you can use to set up a simple JNDI environment for test suites or stand-alone
applications. If, for example, JDBC ``DataSource``s get bound to the same JNDI names in
test code as within a Java EE container, you can reuse both application code and
configuration in testing scenarios without modification.


[[mock-objects-servlet]]
==== Servlet API

The `org.springframework.mock.web` package contains a comprehensive set of Servlet API
mock objects that are useful for testing web contexts, controllers, and filters. These
mock objects are targeted at usage with Spring's Web MVC framework and are generally more
convenient to use than dynamic mock objects such as http://easymock.org/[EasyMock] or
alternative Servlet API mock objects such as http://www.mockobjects.com[MockObjects]. Since
Spring Framework 4.0, the set of mocks in the `org.springframework.mock.web` package is
based on the Servlet 3.0 API.

For thorough integration testing of your Spring MVC and REST ``Controller``s in
conjunction with your `WebApplicationContext` configuration for Spring MVC, see the
<<spring-mvc-test-framework,_Spring MVC Test Framework_>>.


[[mock-objects-portlet]]
==== Portlet API

The `org.springframework.mock.web.portlet` package contains a set of Portlet API mock
objects, targeted at usage with Spring's Portlet MVC framework.



[[unit-testing-support-classes]]
=== Unit Testing support Classes


[[unit-testing-utilities]]
==== General testing utilities

The `org.springframework.test.util` package contains several general purpose utilities
for use in unit and integration testing.

`ReflectionTestUtils` is a collection of reflection-based utility methods. Developers use
these methods in testing scenarios where they need to change the value of a constant, set
a non-`public` field, invoke a non-`public` setter method, or invoke a non-`public`
_configuration_ or _lifecycle_ callback method when testing application code involving
use cases such as the following.

* ORM frameworks such as JPA and Hibernate that condone `private` or `protected` field
  access as opposed to `public` setter methods for properties in a domain entity.
* Spring's support for annotations such as `@Autowired`, `@Inject`, and `@Resource`,
  which provides dependency injection for `private` or `protected` fields, setter
  methods, and configuration methods.
* Use of annotations such as `@PostConstruct` and `@PreDestroy` for lifecycle callback
  methods.

`AopTestUtils` is a collection of AOP-related utility methods. These methods can be used
to obtain a reference to the underlying target object hidden behind one or more Spring
proxies. For example, if you have configured a bean as a dynamic mock using a library
like EasyMock or Mockito and the mock is wrapped in a Spring proxy, you may need direct
access to the underlying mock in order to configure expectations on it and perform
verifications. For Spring's core AOP utilities, see `AopUtils` and `AopProxyUtils`.


[[unit-testing-spring-mvc]]
==== Spring MVC

The `org.springframework.test.web` package contains `ModelAndViewAssert`, which you can
use in combination with JUnit, TestNG, or any other testing framework for unit tests
dealing with Spring MVC `ModelAndView` objects.

.Unit testing Spring MVC Controllers
[TIP]
====
To unit test your Spring MVC ``Controller``s as POJOs, use `ModelAndViewAssert` combined
with `MockHttpServletRequest`, `MockHttpSession`, and so on from Spring's
<<mock-objects-servlet, Servlet API mocks>>. For thorough integration testing of your
Spring MVC and REST ``Controller``s in conjunction with your `WebApplicationContext`
configuration for Spring MVC, use the <<spring-mvc-test-framework,_Spring MVC Test
Framework_>> instead.
====




[[integration-testing]]
== Integration Testing



[[integration-testing-overview]]
=== Overview

It is important to be able to perform some integration testing without requiring
deployment to your application server or connecting to other enterprise infrastructure.
This will enable you to test things such as:

* The correct wiring of your Spring IoC container contexts.
* Data access using JDBC or an ORM tool. This would include such things as the
  correctness of SQL statements, Hibernate queries, JPA entity mappings, etc.

The Spring Framework provides first-class support for integration testing in the
`spring-test` module. The name of the actual JAR file might include the release version
and might also be in the long `org.springframework.test` form, depending on where you
get it from (see the <<dependency-management,section on Dependency Management>> for an
explanation). This library includes the `org.springframework.test` package, which
contains valuable classes for integration testing with a Spring container. This testing
does not rely on an application server or other deployment environment. Such tests are
slower to run than unit tests but much faster than the equivalent Selenium tests or remote
tests that rely on deployment to an application server.

In Spring 2.5 and later, unit and integration testing support is provided in the form of
the annotation-driven <<testcontext-framework,Spring TestContext Framework>>. The
TestContext framework is agnostic of the actual testing framework in use, thus allowing
instrumentation of tests in various environments including JUnit, TestNG, and so on.



[[integration-testing-goals]]
=== Goals of Integration Testing

Spring's integration testing support has the following primary goals:

* To manage <<testing-ctx-management,Spring IoC container caching>> between test
  execution.
* To provide <<testing-fixture-di,Dependency Injection of test fixture instances>>.
* To provide <<testing-tx,transaction management>> appropriate to integration testing.
* To supply <<testing-support-classes,Spring-specific base classes>> that assist
  developers in writing integration tests.

The next few sections describe each goal and provide links to implementation and
configuration details.


[[testing-ctx-management]]
==== Context management and caching

The Spring TestContext Framework provides consistent loading of Spring
``ApplicationContext``s and ``WebApplicationContext``s as well as caching of those
contexts. Support for the caching of loaded contexts is important, because startup time
can become an issue -- not because of the overhead of Spring itself, but because the
objects instantiated by the Spring container take time to instantiate. For example, a
project with 50 to 100 Hibernate mapping files might take 10 to 20 seconds to load the
mapping files, and incurring that cost before running every test in every test fixture
leads to slower overall test runs that reduce developer productivity.

Test classes typically declare either an array of __resource locations__ for XML or Groovy
configuration metadata -- often in the classpath -- or an array of __annotated classes__
that is used to configure the application. These locations or classes are the same as or
similar to those specified in `web.xml` or other configuration files for production
deployments.

By default, once loaded, the configured `ApplicationContext` is reused for each test.
Thus the setup cost is incurred only once per test suite, and subsequent test execution
is much faster. In this context, the term __test suite__ means all tests run in the same
JVM -- for example, all tests run from an Ant, Maven, or Gradle build for a given
project or module. In the unlikely case that a test corrupts the application context and
requires reloading -- for example, by modifying a bean definition or the state of an
application object -- the TestContext framework can be configured to reload the
configuration and rebuild the application context before executing the next test.

See <<testcontext-ctx-management>> and <<testcontext-ctx-management-caching>> with the
TestContext framework.


[[testing-fixture-di]]
==== Dependency Injection of test fixtures

When the TestContext framework loads your application context, it can optionally
configure instances of your test classes via Dependency Injection. This provides a
convenient mechanism for setting up test fixtures using preconfigured beans from your
application context. A strong benefit here is that you can reuse application contexts
across various testing scenarios (e.g., for configuring Spring-managed object graphs,
transactional proxies, ``DataSource``s, etc.), thus avoiding the need to duplicate
complex test fixture setup for individual test cases.

As an example, consider the scenario where we have a class, `HibernateTitleRepository`,
that implements data access logic for a `Title` domain entity. We want to write
integration tests that test the following areas:

* The Spring configuration: basically, is everything related to the configuration of the
  `HibernateTitleRepository` bean correct and present?
* The Hibernate mapping file configuration: is everything mapped correctly, and are the
  correct lazy-loading settings in place?
* The logic of the `HibernateTitleRepository`: does the configured instance of this
  class perform as anticipated?

See dependency injection of test fixtures with the <<testcontext-fixture-di,TestContext
framework>>.


[[testing-tx]]
==== Transaction management

One common issue in tests that access a real database is their effect on the state of
the persistence store. Even when you're using a development database, changes to the
state may affect future tests. Also, many operations -- such as inserting or modifying
persistent data -- cannot be performed (or verified) outside a transaction.

The TestContext framework addresses this issue. By default, the framework will create
and roll back a transaction for each test. You simply write code that can assume the
existence of a transaction. If you call transactionally proxied objects in your tests,
they will behave correctly, according to their configured transactional semantics. In
addition, if a test method deletes the contents of selected tables while running within
the transaction managed for the test, the transaction will roll back by default, and the
database will return to its state prior to execution of the test. Transactional support
is provided to a test via a `PlatformTransactionManager` bean defined in the test's
application context.

If you want a transaction to commit -- unusual, but occasionally useful when you want a
particular test to populate or modify the database -- the TestContext framework can be
instructed to cause the transaction to commit instead of roll back via the
<<integration-testing-annotations, `@Commit`>> annotation.

See transaction management with the <<testcontext-tx,TestContext framework>>.


[[testing-support-classes]]
==== Support classes for integration testing

The Spring TestContext Framework provides several `abstract` support classes that
simplify the writing of integration tests. These base test classes provide well-defined
hooks into the testing framework as well as convenient instance variables and methods,
which enable you to access:

* The `ApplicationContext`, for performing explicit bean lookups or testing the state of
  the context as a whole.
* A `JdbcTemplate`, for executing SQL statements to query the database. Such queries can
  be used to confirm database state both __prior to__ and __after__ execution of
  database-related application code, and Spring ensures that such queries run in the
  scope of the same transaction as the application code. When used in conjunction with
  an ORM tool, be sure to avoid <<testcontext-tx-false-positives,false positives>>.

In addition, you may want to create your own custom, application-wide superclass with
instance variables and methods specific to your project.

See support classes for the <<testcontext-support-classes,TestContext framework>>.



[[integration-testing-support-jdbc]]
=== JDBC Testing Support

The `org.springframework.test.jdbc` package contains `JdbcTestUtils`, which is a
collection of JDBC related utility functions intended to simplify standard database
testing scenarios. Specifically, `JdbcTestUtils` provides the following static utility
methods.

* `countRowsInTable(..)`: counts the number of rows in the given table
* `countRowsInTableWhere(..)`: counts the number of rows in the given table, using
the provided `WHERE` clause
* `deleteFromTables(..)`: deletes all rows from the specified tables
* `deleteFromTableWhere(..)`: deletes rows from the given table, using the provided
`WHERE` clause
* `dropTables(..)`: drops the specified tables

__Note that <<testcontext-support-classes-junit4,
`AbstractTransactionalJUnit4SpringContextTests`>> and
<<testcontext-support-classes-testng, `AbstractTransactionalTestNGSpringContextTests`>>
provide convenience methods which delegate to the aforementioned methods in
`JdbcTestUtils`.__

The `spring-jdbc` module provides support for configuring and launching an embedded
database which can be used in integration tests that interact with a database. For
details, see <<jdbc-embedded-database-support>> and
<<jdbc-embedded-database-dao-testing>>.



[[integration-testing-annotations]]
=== Annotations



[[integration-testing-annotations-spring]]
==== Spring Testing Annotations

The Spring Framework provides the following set of __Spring-specific__ annotations that
you can use in your unit and integration tests in conjunction with the TestContext
framework. Refer to the corresponding javadocs for further information, including
default attribute values, attribute aliases, and so on.

===== @BootstrapWith

`@BootstrapWith` is a class-level annotation that is used to configure how the _Spring
TestContext Framework_ is bootstrapped. Specifically, `@BootstrapWith` is used to specify
a custom `TestContextBootstrapper`. Consult the <<testcontext-bootstrapping,Bootstrapping
the TestContext framework>> section for further details.

===== @ContextConfiguration

`@ContextConfiguration` defines class-level metadata that is used to determine how to
load and configure an `ApplicationContext` for integration tests. Specifically,
`@ContextConfiguration` declares the application context resource `locations` or the
annotated `classes` that will be used to load the context.

Resource locations are typically XML configuration files or Groovy scripts located in
the classpath; whereas, annotated classes are typically `@Configuration` classes. However,
resource locations can also refer to files and scripts in the file system, and annotated
classes can be component classes, etc.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	**@ContextConfiguration**("/test-config.xml")
	public class XmlApplicationContextTests {
		// class body...
	}
----

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	**@ContextConfiguration**(**classes** = TestConfig.class)
	public class ConfigClassApplicationContextTests {
		// class body...
	}
----

As an alternative or in addition to declaring resource locations or annotated classes,
`@ContextConfiguration` may be used to declare `ApplicationContextInitializer` classes.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	**@ContextConfiguration**(**initializers** = CustomContextIntializer.class)
	public class ContextInitializerTests {
		// class body...
	}
----

`@ContextConfiguration` may optionally be used to declare the `ContextLoader` strategy
as well. Note, however, that you typically do not need to explicitly configure the
loader since the default loader supports either resource `locations` or annotated
`classes` as well as `initializers`.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	**@ContextConfiguration**(**locations** = "/test-context.xml", **loader** = CustomContextLoader.class)
	public class CustomLoaderXmlApplicationContextTests {
		// class body...
	}
----

[NOTE]
====
`@ContextConfiguration` provides support for __inheriting__ resource locations or
configuration classes as well as context initializers declared by superclasses by
default.
====

See <<testcontext-ctx-management>> and the `@ContextConfiguration` javadocs for
further details.

===== @WebAppConfiguration

`@WebAppConfiguration` is a class-level annotation that is used to declare that the
`ApplicationContext` loaded for an integration test should be a `WebApplicationContext`.
The mere presence of `@WebAppConfiguration` on a test class ensures that a
`WebApplicationContext` will be loaded for the test, using the default value of
`"file:src/main/webapp"` for the path to the root of the web application (i.e., the
__resource base path__). The resource base path is used behind the scenes to create a
`MockServletContext` which serves as the `ServletContext` for the test's
`WebApplicationContext`.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@ContextConfiguration
	**@WebAppConfiguration**
	public class WebAppTests {
		// class body...
	}
----

To override the default, specify a different base resource path via the __implicit__
`value` attribute. Both `classpath:` and `file:` resource prefixes are supported. If no
resource prefix is supplied the path is assumed to be a file system resource.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@ContextConfiguration
	**@WebAppConfiguration("classpath:test-web-resources")**
	public class WebAppTests {
		// class body...
	}
----

Note that `@WebAppConfiguration` must be used in conjunction with
`@ContextConfiguration`, either within a single test class or within a test class
hierarchy. See the `@WebAppConfiguration` javadocs for further details.

===== @ContextHierarchy

`@ContextHierarchy` is a class-level annotation that is used to define a hierarchy of
``ApplicationContext``s for integration tests. `@ContextHierarchy` should be declared
with a list of one or more `@ContextConfiguration` instances, each of which defines a
level in the context hierarchy. The following examples demonstrate the use of
`@ContextHierarchy` within a single test class; however, `@ContextHierarchy` can also be
used within a test class hierarchy.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@ContextHierarchy({
		@ContextConfiguration("/parent-config.xml"),
		@ContextConfiguration("/child-config.xml")
	})
	public class ContextHierarchyTests {
		// class body...
	}
----

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@WebAppConfiguration
	@ContextHierarchy({
		@ContextConfiguration(classes = AppConfig.class),
		@ContextConfiguration(classes = WebConfig.class)
	})
	public class WebIntegrationTests {
		// class body...
	}
----

If you need to merge or override the configuration for a given level of the context
hierarchy within a test class hierarchy, you must explicitly name that level by
supplying the same value to the `name` attribute in `@ContextConfiguration` at each
corresponding level in the class hierarchy. See
<<testcontext-ctx-management-ctx-hierarchies>> and the `@ContextHierarchy` javadocs
for further examples.

===== @ActiveProfiles

`@ActiveProfiles` is a class-level annotation that is used to declare which __bean
definition profiles__ should be active when loading an `ApplicationContext` for an
integration test.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@ContextConfiguration
	**@ActiveProfiles**("dev")
	public class DeveloperTests {
		// class body...
	}
----

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@ContextConfiguration
	**@ActiveProfiles**({"dev", "integration"})
	public class DeveloperIntegrationTests {
		// class body...
	}
----

[NOTE]
====
`@ActiveProfiles` provides support for __inheriting__ active bean definition profiles
declared by superclasses by default. It is also possible to resolve active bean
definition profiles programmatically by implementing a custom
<<testcontext-ctx-management-env-profiles-ActiveProfilesResolver,`ActiveProfilesResolver`>>
and registering it via the `resolver` attribute of `@ActiveProfiles`.
====

See <<testcontext-ctx-management-env-profiles>> and the `@ActiveProfiles` javadocs
for examples and further details.

===== @TestPropertySource

`@TestPropertySource` is a class-level annotation that is used to configure the locations
of properties files and inlined properties to be added to the set of `PropertySources` in
the `Environment` for an `ApplicationContext` loaded for an integration test.

Test property sources have higher precedence than those loaded from the operating
system's environment or Java system properties as well as property sources added by the
application declaratively via `@PropertySource` or programmatically. Thus, test property
sources can be used to selectively override properties defined in system and application
property sources. Furthermore, inlined properties have higher precedence than properties
loaded from resource locations.

The following example demonstrates how to declare a properties file from the classpath.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@ContextConfiguration
	**@TestPropertySource**("/test.properties")
	public class MyIntegrationTests {
		// class body...
	}
----

The following example demonstrates how to declare _inlined_ properties.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@ContextConfiguration
	**@TestPropertySource**(properties = { "timezone = GMT", "port: 4242" })
	public class MyIntegrationTests {
		// class body...
	}
----

===== @DirtiesContext

`@DirtiesContext` indicates that the underlying Spring `ApplicationContext` has been
__dirtied__ during the execution of a test (i.e., modified or corrupted in some manner --
for example, by changing the state of a singleton bean) and should be closed. When an
application context is marked __dirty__, it is removed from the testing framework's cache
and closed. As a consequence, the underlying Spring container will be rebuilt for any
subsequent test that requires a context with the same configuration metadata.

`@DirtiesContext` can be used as both a class-level and method-level annotation within
the same class or class hierarchy. In such scenarios, the `ApplicationContext` is marked
as __dirty__ before or after any such annotated method as well as before or after the
current test class, depending on the configured `methodMode` and `classMode`.

The following examples explain when the context would be dirtied for various
configuration scenarios:

* Before the current test class, when declared on a class with class mode set to
`BEFORE_CLASS`.

+

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	**@DirtiesContext(classMode = BEFORE_CLASS)**
	public class FreshContextTests {
		// some tests that require a new Spring container
	}
----

+

* After the current test class, when declared on a class with class mode set to
`AFTER_CLASS` (i.e., the default class mode).

+

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	**@DirtiesContext**
	public class ContextDirtyingTests {
		// some tests that result in the Spring container being dirtied
	}
----

+

* Before each test method in the current test class, when declared on a class with class
mode set to `BEFORE_EACH_TEST_METHOD.`

+

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	**@DirtiesContext(classMode = BEFORE_EACH_TEST_METHOD)**
	public class FreshContextTests {
		// some tests that require a new Spring container
	}
----

+

* After each test method in the current test class, when declared on a class with class
mode set to `AFTER_EACH_TEST_METHOD.`

+

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	**@DirtiesContext(classMode = AFTER_EACH_TEST_METHOD)**
	public class ContextDirtyingTests {
		// some tests that result in the Spring container being dirtied
	}
----

+

* Before the current test, when declared on a method with the method mode set to
`BEFORE_METHOD`.

+

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	**@DirtiesContext(methodMode = BEFORE_METHOD)**
	@Test
	public void testProcessWhichRequiresFreshAppCtx() {
		// some logic that requires a new Spring container
	}
----

+

* After the current test, when declared on a method with the method mode set to
`AFTER_METHOD` (i.e., the default method mode).

+

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	**@DirtiesContext**
	@Test
	public void testProcessWhichDirtiesAppCtx() {
		// some logic that results in the Spring container being dirtied
	}
----

If `@DirtiesContext` is used in a test whose context is configured as part of a context
hierarchy via `@ContextHierarchy`, the `hierarchyMode` flag can be used to control how
the context cache is cleared. By default an __exhaustive__ algorithm will be used that
clears the context cache including not only the current level but also all other context
hierarchies that share an ancestor context common to the current test; all
``ApplicationContext``s that reside in a sub-hierarchy of the common ancestor context
will be removed from the context cache and closed. If the __exhaustive__ algorithm is
overkill for a particular use case, the simpler __current level__ algorithm can be
specified instead, as seen below.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@ContextHierarchy({
		@ContextConfiguration("/parent-config.xml"),
		@ContextConfiguration("/child-config.xml")
	})
	public class BaseTests {
		// class body...
	}

	public class ExtendedTests extends BaseTests {

		@Test
		@DirtiesContext(**hierarchyMode = CURRENT_LEVEL**)
		public void test() {
			// some logic that results in the child context being dirtied
		}
	}
----

For further details regarding the `EXHAUSTIVE` and `CURRENT_LEVEL` algorithms see the
`DirtiesContext.HierarchyMode` javadocs.

===== @TestExecutionListeners

`@TestExecutionListeners` defines class-level metadata for configuring the
`TestExecutionListener` implementations that should be registered with the
`TestContextManager`. Typically, `@TestExecutionListeners` is used in conjunction with
`@ContextConfiguration`.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@ContextConfiguration
	**@TestExecutionListeners**({CustomTestExecutionListener.class, AnotherTestExecutionListener.class})
	public class CustomTestExecutionListenerTests {
		// class body...
	}
----

`@TestExecutionListeners` supports _inherited_ listeners by default. See the javadocs
for an example and further details.

===== @Commit

`@Commit` indicates that the transaction for a transactional test method should be
__committed__ after the test method has completed. `@Commit` can be used as a direct
replacement for `@Rollback(false)` in order to more explicitly convey the intent of the
code. Analogous to `@Rollback`, `@Commit` may also be declared as a class-level or
method-level annotation.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	**@Commit**
	@Test
	public void testProcessWithoutRollback() {
		// ...
	}
----

===== @Rollback

`@Rollback` indicates whether the transaction for a transactional test method should be
__rolled back__ after the test method has completed. If `true`, the transaction is rolled
back; otherwise, the transaction is committed (see also `@Commit`). Rollback semantics
for integration tests in the Spring TestContext Framework default to `true` even if
`@Rollback` is not explicitly declared.

When declared as a class-level annotation, `@Rollback` defines the default rollback
semantics for all test methods within the test class hierarchy. When declared as a
method-level annotation, `@Rollback` defines rollback semantics for the specific test
method, potentially overriding class-level `@Rollback` or `@Commit` semantics.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	**@Rollback**(false)
	@Test
	public void testProcessWithoutRollback() {
		// ...
	}
----

===== @BeforeTransaction

`@BeforeTransaction` indicates that the annotated `void` method should be executed
__before__ a transaction is started for test methods configured to run within a
transaction via Spring's `@Transactional` annotation. As of Spring Framework 4.3,
`@BeforeTransaction` methods are not required to be `public` and may be declared on Java
8 based interface default methods.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	**@BeforeTransaction**
	void beforeTransaction() {
		// logic to be executed before a transaction is started
	}
----

===== @AfterTransaction

`@AfterTransaction` indicates that the annotated `void` method should be executed
__after__ a transaction is ended for test methods configured to run within a transaction
via Spring's `@Transactional` annotation. As of Spring Framework 4.3, `@AfterTransaction`
methods are not required to be `public` and may be declared on Java 8 based interface
default methods.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	**@AfterTransaction**
	void afterTransaction() {
		// logic to be executed after a transaction has ended
	}
----

===== @Sql

`@Sql` is used to annotate a test class or test method to configure SQL scripts to be
executed against a given database during integration tests.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@Test
	**@Sql**({"/test-schema.sql", "/test-user-data.sql"})
	public void userTest {
		// execute code that relies on the test schema and test data
	}
----

See <<testcontext-executing-sql-declaratively>> for further details.

===== @SqlConfig

`@SqlConfig` defines metadata that is used to determine how to parse and execute SQL
scripts configured via the `@Sql` annotation.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@Test
	@Sql(
		scripts = "/test-user-data.sql",
		config = **@SqlConfig**(commentPrefix = "`", separator = "@@")
	)
	public void userTest {
		// execute code that relies on the test data
	}
----

===== @SqlGroup

`@SqlGroup` is a container annotation that aggregates several `@Sql` annotations.
`@SqlGroup` can be used natively, declaring several nested `@Sql` annotations, or it can
be used in conjunction with Java 8's support for repeatable annotations, where `@Sql` can
simply be declared several times on the same class or method, implicitly generating this
container annotation.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@Test
	**@SqlGroup**({
		@Sql(scripts = "/test-schema.sql", config = @SqlConfig(commentPrefix = "`")),
		@Sql("/test-user-data.sql")
	)}
	public void userTest {
		// execute code that uses the test schema and test data
	}
----


[[integration-testing-annotations-standard]]
==== Standard Annotation Support

The following annotations are supported with standard semantics for all configurations
of the Spring TestContext Framework. Note that these annotations are not specific to
tests and can be used anywhere in the Spring Framework.

* `@Autowired`
* `@Qualifier`
* `@Resource` (javax.annotation) _if JSR-250 is present_
* `@ManagedBean` (javax.annotation) _if JSR-250 is present_
* `@Inject` (javax.inject) _if JSR-330 is present_
* `@Named` (javax.inject) _if JSR-330 is present_
* `@PersistenceContext` (javax.persistence) _if JPA is present_
* `@PersistenceUnit` (javax.persistence) _if JPA is present_
* `@Required`
* `@Transactional`

.JSR-250 Lifecycle Annotations
[NOTE]
====
In the Spring TestContext Framework `@PostConstruct` and `@PreDestroy` may be used with
standard semantics on any application components configured in the `ApplicationContext`;
however, these lifecycle annotations have limited usage within an actual test class.

If a method within a test class is annotated with `@PostConstruct`, that method will be
executed before any __before__ methods of the underlying test framework (e.g., methods
annotated with JUnit 4's `@Before`), and that will apply for every test method in the test
class. On the other hand, if a method within a test class is annotated with
`@PreDestroy`, that method will __never__ be executed. Within a test class it is
therefore recommended to use test lifecycle callbacks from the underlying test framework
instead of `@PostConstruct` and `@PreDestroy`.
====


[[integration-testing-annotations-junit]]
==== Spring JUnit 4 Testing Annotations

The following annotations are __only__ supported when used in conjunction with the
<<testcontext-junit4-runner,SpringRunner>>, <<testcontext-junit4-rules,Spring's JUnit
rules>>, or <<testcontext-support-classes-junit4,Spring's JUnit 4 support classes>>.

===== @IfProfileValue

`@IfProfileValue` indicates that the annotated test is enabled for a specific testing
environment. If the configured `ProfileValueSource` returns a matching `value` for the
provided `name`, the test is enabled. Otherwise, the test will be disabled and
effectively _ignored_.

`@IfProfileValue` can be applied at the class level, the method level, or both.
Class-level usage of `@IfProfileValue` takes precedence over method-level usage for any
methods within that class or its subclasses. Specifically, a test is enabled if it is
enabled both at the class level _and_ at the method level; the absence of
`@IfProfileValue` means the test is implicitly enabled. This is analogous to the
semantics of JUnit 4's `@Ignore` annotation, except that the presence of `@Ignore` always
disables a test.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	**@IfProfileValue**(**name**="java.vendor", **value**="Oracle Corporation")
	@Test
	public void testProcessWhichRunsOnlyOnOracleJvm() {
		// some logic that should run only on Java VMs from Oracle Corporation
	}
----

Alternatively, you can configure `@IfProfileValue` with a list of `values` (with __OR__
semantics) to achieve TestNG-like support for __test groups__ in a JUnit 4 environment.
Consider the following example:

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	**@IfProfileValue**(**name**="test-groups", **values**={"unit-tests", "integration-tests"})
	@Test
	public void testProcessWhichRunsForUnitOrIntegrationTestGroups() {
		// some logic that should run only for unit and integration test groups
	}
----

===== @ProfileValueSourceConfiguration

`@ProfileValueSourceConfiguration` is a class-level annotation that specifies what type
of `ProfileValueSource` to use when retrieving __profile values__ configured through the
`@IfProfileValue` annotation. If `@ProfileValueSourceConfiguration` is not declared for a
test, `SystemProfileValueSource` is used by default.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	**@ProfileValueSourceConfiguration**(CustomProfileValueSource.class)
	public class CustomProfileValueSourceTests {
		// class body...
	}
----

===== @Timed

`@Timed` indicates that the annotated test method must finish execution in a specified
time period (in milliseconds). If the text execution time exceeds the specified time
period, the test fails.

The time period includes execution of the test method itself, any repetitions of the
test (see `@Repeat`), as well as any __set up__ or __tear down__ of the test fixture.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	**@Timed**(millis=1000)
	public void testProcessWithOneSecondTimeout() {
		// some logic that should not take longer than 1 second to execute
	}
----

Spring's `@Timed` annotation has different semantics than JUnit 4's `@Test(timeout=...)`
support. Specifically, due to the manner in which JUnit 4 handles test execution timeouts
(that is, by executing the test method in a separate `Thread`), `@Test(timeout=...)`
preemptively fails the test if the test takes too long. Spring's `@Timed`, on the other
hand, does not preemptively fail the test but rather waits for the test to complete
before failing.

===== @Repeat

`@Repeat` indicates that the annotated test method must be executed repeatedly. The
number of times that the test method is to be executed is specified in the annotation.

The scope of execution to be repeated includes execution of the test method itself as
well as any __set up__ or __tear down__ of the test fixture.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	**@Repeat**(10)
	@Test
	public void testProcessRepeatedly() {
		// ...
	}
----


[[integration-testing-annotations-meta]]
==== Meta-Annotation Support for Testing

It is possible to use most test-related annotations as
<<beans-meta-annotations,meta-annotations>> in order to create custom _composed
annotations_ and reduce configuration duplication across a test suite.

Each of the following may be used as meta-annotations in conjunction with the
<<testcontext-framework,TestContext framework>>.

* `@BootstrapWith`
* `@ContextConfiguration`
* `@ContextHierarchy`
* `@ActiveProfiles`
* `@TestPropertySource`
* `@DirtiesContext`
* `@WebAppConfiguration`
* `@TestExecutionListeners`
* `@Transactional`
* `@BeforeTransaction`
* `@AfterTransaction`
* `@Commit`
* `@Rollback`
* `@Sql`
* `@SqlConfig`
* `@SqlGroup`
* `@Repeat`
* `@Timed`
* `@IfProfileValue`
* `@ProfileValueSourceConfiguration`

For example, if we discover that we are repeating the following configuration
across our JUnit 4 based test suite...

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@RunWith(SpringRunner.class)
	@ContextConfiguration({"/app-config.xml", "/test-data-access-config.xml"})
	@ActiveProfiles("dev")
	@Transactional
	public class OrderRepositoryTests { }

	@RunWith(SpringRunner.class)
	@ContextConfiguration({"/app-config.xml", "/test-data-access-config.xml"})
	@ActiveProfiles("dev")
	@Transactional
	public class UserRepositoryTests { }
----

We can reduce the above duplication by introducing a custom _composed annotation_
that centralizes the common test configuration like this:

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@Target(ElementType.TYPE)
	@Retention(RetentionPolicy.RUNTIME)
	@ContextConfiguration({"/app-config.xml", "/test-data-access-config.xml"})
	@ActiveProfiles("dev")
	@Transactional
	public @interface TransactionalDevTest { }
----

Then we can use our custom `@TransactionalDevTest` annotation to simplify the
configuration of individual test classes as follows:

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@RunWith(SpringRunner.class)
	@TransactionalDevTest
	public class OrderRepositoryTests { }

	@RunWith(SpringRunner.class)
	@TransactionalDevTest
	public class UserRepositoryTests { }
----

For further details, consult the <<annotation-programming-model,Spring Annotation Programming Model>>.



[[testcontext-framework]]
=== Spring TestContext Framework

The __Spring TestContext Framework__ (located in the
`org.springframework.test.context` package) provides generic, annotation-driven unit and
integration testing support that is agnostic of the testing framework in use. The
TestContext framework also places a great deal of importance on __convention over
configuration__ with reasonable defaults that can be overridden through annotation-based
configuration.

In addition to generic testing infrastructure, the TestContext framework provides
explicit support for JUnit 4 and TestNG in the form of `abstract` support classes. For
JUnit 4, Spring also provides a custom JUnit `Runner` and custom JUnit `Rules` that allow
one to write so-called __POJO test classes__. POJO test classes are not required to
extend a particular class hierarchy.

The following section provides an overview of the internals of the TestContext
framework. If you are only interested in _using_ the framework and not necessarily
interested in _extending_ it with your own custom listeners or custom loaders, feel free
to go directly to the configuration (<<testcontext-ctx-management,context management>>,
<<testcontext-fixture-di,dependency injection>>, <<testcontext-tx,transaction
management>>), <<testcontext-support-classes,support classes>>, and
<<integration-testing-annotations,annotation support>> sections.


[[testcontext-key-abstractions]]
==== Key abstractions

The core of the framework consists of the `TestContextManager` class and the
`TestContext`, `TestExecutionListener`, and `SmartContextLoader` interfaces. A
`TestContextManager` is created per test class (e.g., for the execution of all test
methods within a single test class in JUnit 4). The `TestContextManager` in turn manages a
`TestContext` that holds the context of the current test. The `TestContextManager` also
updates the state of the `TestContext` as the test progresses and delegates to
`TestExecutionListener` implementations, which instrument the actual test execution by
providing dependency injection, managing transactions, and so on. A `SmartContextLoader`
is responsible for loading an `ApplicationContext` for a given test class. Consult the
javadocs and the Spring test suite for further information and examples of various
implementations.

===== TestContext

`TestContext` encapsulates the context in which a test is executed, agnostic of the
actual testing framework in use, and provides context management and caching support for
the test instance for which it is responsible. The `TestContext` also delegates to a
`SmartContextLoader` to load an `ApplicationContext` if requested.

===== TestContextManager

`TestContextManager` is the main entry point into the __Spring TestContext Framework__,
which manages a single `TestContext` and signals events to each registered
`TestExecutionListener` at well-defined test execution points:

* prior to any __before class__ or __before all__ methods of a particular testing framework
* test instance post-processing
* prior to any __before__ or __before each__ methods of a particular testing framework
* after any __after__ or __after each__ methods of a particular testing framework
* after any __after class__ or __after all__ methods of a particular testing framework

===== TestExecutionListener

`TestExecutionListener` defines the API for reacting to test execution events published
by the `TestContextManager` with which the listener is registered. See
<<testcontext-tel-config>>.

===== Context Loaders

`ContextLoader` is a strategy interface that was introduced in Spring 2.5 for loading an
`ApplicationContext` for an integration test managed by the Spring TestContext Framework.
Implement `SmartContextLoader` instead of this interface in order to provide support for
annotated classes, active bean definition profiles, test property sources, context
hierarchies, and `WebApplicationContext` support.

`SmartContextLoader` is an extension of the `ContextLoader` interface introduced in
Spring 3.1. The `SmartContextLoader` SPI supersedes the `ContextLoader` SPI that was
introduced in Spring 2.5. Specifically, a `SmartContextLoader` can choose to process
resource `locations`, annotated `classes`, or context `initializers`. Furthermore, a
`SmartContextLoader` can set active bean definition profiles and test property sources in
the context that it loads.

Spring provides the following implementations:

* `DelegatingSmartContextLoader`: one of two default loaders which delegates internally
to an `AnnotationConfigContextLoader`, a `GenericXmlContextLoader`, or a
`GenericGroovyXmlContextLoader` depending either on the configuration declared for the
test class or on the presence of default locations or default configuration classes.
Groovy support is only enabled if Groovy is on the classpath.
* `WebDelegatingSmartContextLoader`: one of two default loaders which delegates
internally to an `AnnotationConfigWebContextLoader`, a `GenericXmlWebContextLoader`, or a
`GenericGroovyXmlWebContextLoader` depending either on the configuration declared for the
test class or on the presence of default locations or default configuration classes. A
web `ContextLoader` will only be used if `@WebAppConfiguration` is present on the test
class. Groovy support is only enabled if Groovy is on the classpath.
* `AnnotationConfigContextLoader`: loads a standard `ApplicationContext` from
__annotated classes__.
* `AnnotationConfigWebContextLoader`: loads a `WebApplicationContext` from __annotated
classes__.
* `GenericGroovyXmlContextLoader`: loads a standard `ApplicationContext` from __resource
locations__ that are either Groovy scripts or XML configuration files.
* `GenericGroovyXmlWebContextLoader`: loads a `WebApplicationContext` from __resource
locations__ that are either Groovy scripts or XML configuration files.
* `GenericXmlContextLoader`: loads a standard `ApplicationContext` from XML __resource
locations__.
* `GenericXmlWebContextLoader`: loads a `WebApplicationContext` from XML __resource
locations__.
* `GenericPropertiesContextLoader`: loads a standard `ApplicationContext` from Java
Properties files.


[[testcontext-bootstrapping]]
==== Bootstrapping the TestContext framework

The default configuration for the internals of the Spring TestContext Framework is
sufficient for all common use cases. However, there are times when a development team or
third party framework would like to change the default `ContextLoader`, implement a
custom `TestContext` or `ContextCache`, augment the default sets of
`ContextCustomizerFactory` and `TestExecutionListener` implementations, etc. For such low
level control over how the TestContext framework operates, Spring provides a
bootstrapping strategy.

`TestContextBootstrapper` defines the SPI for _bootstrapping_ the TestContext framework.
A `TestContextBootstrapper` is used by the `TestContextManager` to load the
`TestExecutionListener` implementations for the current test and to build the
`TestContext` that it manages. A custom bootstrapping strategy can be configured for a
test class (or test class hierarchy) via `@BootstrapWith`, either directly or as a
meta-annotation. If a bootstrapper is not explicitly configured via `@BootstrapWith`,
either the `DefaultTestContextBootstrapper` or the `WebTestContextBootstrapper` will be
used, depending on the presence of `@WebAppConfiguration`.

Since the `TestContextBootstrapper` SPI is likely to change in the future in order to
accommodate new requirements, implementers are strongly encouraged not to implement this
interface directly but rather to extend `AbstractTestContextBootstrapper` or one of its
concrete subclasses instead.


[[testcontext-tel-config]]
==== TestExecutionListener configuration

Spring provides the following `TestExecutionListener` implementations that are registered
by default, exactly in this order.

* `ServletTestExecutionListener`: configures Servlet API mocks for a
  `WebApplicationContext`
* `DirtiesContextBeforeModesTestExecutionListener`: handles the `@DirtiesContext` annotation for
  _before_ modes
* `DependencyInjectionTestExecutionListener`: provides dependency injection for the test
  instance
* `DirtiesContextTestExecutionListener`: handles the `@DirtiesContext` annotation for
  _after_ modes
* `TransactionalTestExecutionListener`: provides transactional test execution with
  default rollback semantics
* `SqlScriptsTestExecutionListener`: executes SQL scripts configured via the `@Sql`
  annotation

[[testcontext-tel-config-registering-tels]]
===== Registering custom TestExecutionListeners

Custom ``TestExecutionListener``s can be registered for a test class and its subclasses
via the `@TestExecutionListeners` annotation. See
<<integration-testing-annotations,annotation support>> and the javadocs for
`@TestExecutionListeners` for details and examples.

[[testcontext-tel-config-automatic-discovery]]
===== Automatic discovery of default TestExecutionListeners

Registering custom ``TestExecutionListener``s via `@TestExecutionListeners` is suitable
for custom listeners that are used in limited testing scenarios; however, it can become
cumbersome if a custom listener needs to be used across a test suite. Since Spring
Framework 4.1, this issue is addressed via support for automatic discovery of _default_
`TestExecutionListener` implementations via the `SpringFactoriesLoader` mechanism.

Specifically, the `spring-test` module declares all core default
``TestExecutionListener``s under the
`org.springframework.test.context.TestExecutionListener` key in its
`META-INF/spring.factories` properties file. Third-party frameworks and developers can
contribute their own ``TestExecutionListener``s to the list of default listeners in the
same manner via their own `META-INF/spring.factories` properties file.

[[testcontext-tel-config-ordering]]
===== Ordering TestExecutionListeners

When the TestContext framework discovers default ``TestExecutionListener``s via the
aforementioned `SpringFactoriesLoader` mechanism, the instantiated listeners are sorted
using Spring's `AnnotationAwareOrderComparator` which honors Spring's `Ordered` interface
and `@Order` annotation for ordering. `AbstractTestExecutionListener` and all default
``TestExecutionListener``s provided by Spring implement `Ordered` with appropriate
values. Third-party frameworks and developers should therefore make sure that their
_default_ ``TestExecutionListener``s are registered in the proper order by implementing
`Ordered` or declaring `@Order`. Consult the javadocs for the `getOrder()` methods of the
core default ``TestExecutionListener``s for details on what values are assigned to each
core listener.

[[testcontext-tel-config-merging]]
===== Merging TestExecutionListeners

If a custom `TestExecutionListener` is registered via `@TestExecutionListeners`, the
_default_ listeners will not be registered. In most common testing scenarios, this
effectively forces the developer to manually declare all default listeners in addition to
any custom listeners. The following listing demonstrates this style of configuration.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@ContextConfiguration
	@TestExecutionListeners({
		MyCustomTestExecutionListener.class,
		ServletTestExecutionListener.class,
		DirtiesContextBeforeModesTestExecutionListener.class,
		DependencyInjectionTestExecutionListener.class,
		DirtiesContextTestExecutionListener.class,
		TransactionalTestExecutionListener.class,
		SqlScriptsTestExecutionListener.class
	})
	public class MyTest {
		// class body...
	}
----

The challenge with this approach is that it requires that the developer know exactly
which listeners are registered by default. Moreover, the set of default listeners can
change from release to release -- for example, `SqlScriptsTestExecutionListener` was
introduced in Spring Framework 4.1, and `DirtiesContextBeforeModesTestExecutionListener`
was introduced in Spring Framework 4.2. Furthermore, third-party frameworks like Spring
Security register their own default ``TestExecutionListener``s via the aforementioned
<<testcontext-tel-config-automatic-discovery, automatic discovery mechanism>>.

To avoid having to be aware of and re-declare **all** _default_ listeners, the
`mergeMode` attribute of `@TestExecutionListeners` can be set to
`MergeMode.MERGE_WITH_DEFAULTS`. `MERGE_WITH_DEFAULTS` indicates that locally declared
listeners should be merged with the default listeners. The merging algorithm ensures that
duplicates are removed from the list and that the resulting set of merged listeners is
sorted according to the semantics of `AnnotationAwareOrderComparator` as described in
<<testcontext-tel-config-ordering>>. If a listener implements `Ordered` or is annotated
with `@Order` it can influence the position in which it is merged with the defaults;
otherwise, locally declared listeners will simply be appended to the list of default
listeners when merged.

For example, if the `MyCustomTestExecutionListener` class in the previous example
configures its `order` value (for example, `500`) to be less than the order of the
`ServletTestExecutionListener` (which happens to be `1000`), the
`MyCustomTestExecutionListener` can then be automatically merged with the list of
defaults _in front of_ the `ServletTestExecutionListener`, and the previous example could
be replaced with the following.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@ContextConfiguration
	@TestExecutionListeners(
		listeners = MyCustomTestExecutionListener.class,
		mergeMode = MERGE_WITH_DEFAULTS
	)
	public class MyTest {
		// class body...
	}
----


[[testcontext-ctx-management]]
==== Context management

Each `TestContext` provides context management and caching support for the test instance
it is responsible for. Test instances do not automatically receive access to the
configured `ApplicationContext`. However, if a test class implements the
`ApplicationContextAware` interface, a reference to the `ApplicationContext` is supplied
to the test instance. Note that `AbstractJUnit4SpringContextTests` and
`AbstractTestNGSpringContextTests` implement `ApplicationContextAware` and therefore
provide access to the `ApplicationContext` automatically.

.@Autowired ApplicationContext
[TIP]
====
As an alternative to implementing the `ApplicationContextAware` interface, you can
inject the application context for your test class through the `@Autowired` annotation
on either a field or setter method. For example:

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@RunWith(SpringRunner.class)
	@ContextConfiguration
	public class MyTest {

		**@Autowired**
		private ApplicationContext applicationContext;

		// class body...
	}
----

Similarly, if your test is configured to load a `WebApplicationContext`, you can inject
the web application context into your test as follows:

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@RunWith(SpringRunner.class)
	**@WebAppConfiguration**
	@ContextConfiguration
	public class MyWebAppTest {
		**@Autowired**
		private WebApplicationContext wac;

		// class body...
	}
----

Dependency injection via `@Autowired` is provided by the
`DependencyInjectionTestExecutionListener` which is configured by default (see
<<testcontext-fixture-di>>).
====

Test classes that use the TestContext framework do not need to extend any particular
class or implement a specific interface to configure their application context. Instead,
configuration is achieved simply by declaring the `@ContextConfiguration` annotation at
the class level. If your test class does not explicitly declare application context
resource `locations` or annotated `classes`, the configured `ContextLoader` determines
how to load a context from a default location or default configuration classes. In
addition to context resource `locations` and annotated `classes`, an application context
can also be configured via application context `initializers`.

The following sections explain how to configure an `ApplicationContext` via XML
configuration files, Groovy scripts, annotated classes (typically `@Configuration`
classes), or context initializers using Spring's `@ContextConfiguration` annotation.
Alternatively, you can implement and configure your own custom `SmartContextLoader` for
advanced use cases.

[[testcontext-ctx-management-xml]]
===== Context configuration with XML resources

To load an `ApplicationContext` for your tests using XML configuration files, annotate
your test class with `@ContextConfiguration` and configure the `locations` attribute with
an array that contains the resource locations of XML configuration metadata. A plain or
relative path -- for example `"context.xml"` -- will be treated as a classpath resource
that is relative to the package in which the test class is defined. A path starting with
a slash is treated as an absolute classpath location, for example
`"/org/example/config.xml"`. A path which represents a resource URL (i.e., a path
prefixed with `classpath:`, `file:`, `http:`, etc.) will be used __as is__.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@RunWith(SpringRunner.class)
	// ApplicationContext will be loaded from "/app-config.xml" and
	// "/test-config.xml" in the root of the classpath
	**@ContextConfiguration(locations={"/app-config.xml", "/test-config.xml"})**
	public class MyTest {
		// class body...
	}
----

`@ContextConfiguration` supports an alias for the `locations` attribute through the
standard Java `value` attribute. Thus, if you do not need to declare additional
attributes in `@ContextConfiguration`, you can omit the declaration of the `locations`
attribute name and declare the resource locations by using the shorthand format
demonstrated in the following example.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@RunWith(SpringRunner.class)
	**@ContextConfiguration({"/app-config.xml", "/test-config.xml"})**
	public class MyTest {
		// class body...
	}
----

If you omit both the `locations` and `value` attributes from the `@ContextConfiguration`
annotation, the TestContext framework will attempt to detect a default XML resource
location. Specifically, `GenericXmlContextLoader` and `GenericXmlWebContextLoader` detect
a default location based on the name of the test class. If your class is named
`com.example.MyTest`, `GenericXmlContextLoader` loads your application context from
`"classpath:com/example/MyTest-context.xml"`.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	package com.example;

	@RunWith(SpringRunner.class)
	// ApplicationContext will be loaded from
	// "classpath:com/example/MyTest-context.xml"
	**@ContextConfiguration**
	public class MyTest {
		// class body...
	}
----

[[testcontext-ctx-management-groovy]]
===== Context configuration with Groovy scripts

To load an `ApplicationContext` for your tests using Groovy scripts that utilize the
<<groovy-bean-definition-dsl,Groovy Bean Definition DSL>>, annotate your test class with
`@ContextConfiguration` and configure the `locations` or `value` attribute with an array
that contains the resource locations of Groovy scripts. Resource lookup semantics for
Groovy scripts are the same as those described for <<testcontext-ctx-management-xml,XML
configuration files>>.


.Enabling Groovy script support
[TIP]
====
Support for using Groovy scripts to load an `ApplicationContext` in the Spring
TestContext Framework is enabled automatically if Groovy is on the classpath.
====

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@RunWith(SpringRunner.class)
	// ApplicationContext will be loaded from "/AppConfig.groovy" and
	// "/TestConfig.groovy" in the root of the classpath
	**@ContextConfiguration({"/AppConfig.groovy", "/TestConfig.Groovy"})**
	public class MyTest {
		// class body...
	}
----

If you omit both the `locations` and `value` attributes from the `@ContextConfiguration`
annotation, the TestContext framework will attempt to detect a default Groovy script.
Specifically, `GenericGroovyXmlContextLoader` and `GenericGroovyXmlWebContextLoader`
detect a default location based on the name of the test class. If your class is named
`com.example.MyTest`, the Groovy context loader will load your application context from
`"classpath:com/example/MyTestContext.groovy"`.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	package com.example;

	@RunWith(SpringRunner.class)
	// ApplicationContext will be loaded from
	// "classpath:com/example/MyTestContext.groovy"
	**@ContextConfiguration**
	public class MyTest {
		// class body...
	}
----

.Declaring XML config and Groovy scripts simultaneously
[TIP]
====
Both XML configuration files and Groovy scripts can be declared simultaneously via the
`locations` or `value` attribute of `@ContextConfiguration`. If the path to a configured
resource location ends with `.xml` it will be loaded using an `XmlBeanDefinitionReader`;
otherwise it will be loaded using a `GroovyBeanDefinitionReader`.

The following listing demonstrates how to combine both in an integration test.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@RunWith(SpringRunner.class)
	// ApplicationContext will be loaded from
	// "/app-config.xml" and "/TestConfig.groovy"
	@ContextConfiguration({ "/app-config.xml", "/TestConfig.groovy" })
	public class MyTest {
		// class body...
	}
----
====

[[testcontext-ctx-management-javaconfig]]
===== Context configuration with annotated classes

To load an `ApplicationContext` for your tests using __annotated classes__ (see
<<beans-java>>), annotate your test class with `@ContextConfiguration` and configure the
`classes` attribute with an array that contains references to annotated classes.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@RunWith(SpringRunner.class)
	// ApplicationContext will be loaded from AppConfig and TestConfig
	**@ContextConfiguration(classes = {AppConfig.class, TestConfig.class})**
	public class MyTest {
		// class body...
	}
----

.Annotated Classes
[TIP]
====
The term __annotated class__ can refer to any of the following.

* A class annotated with `@Configuration`
* A component (i.e., a class annotated with `@Component`, `@Service`, `@Repository`, etc.)
* A JSR-330 compliant class that is annotated with `javax.inject` annotations
* Any other class that contains `@Bean`-methods

Consult the javadocs of `@Configuration` and `@Bean` for further information regarding
the configuration and semantics of __annotated classes__, paying special attention to
the discussion of __`@Bean` Lite Mode__.
====

If you omit the `classes` attribute from the `@ContextConfiguration` annotation, the
TestContext framework will attempt to detect the presence of default configuration
classes. Specifically, `AnnotationConfigContextLoader` and
`AnnotationConfigWebContextLoader` will detect all `static` nested classes of the test class
that meet the requirements for configuration class implementations as specified in the
`@Configuration` javadocs. In the following example, the `OrderServiceTest` class
declares a `static` nested configuration class named `Config` that will be automatically
used to load the `ApplicationContext` for the test class. Note that the name of the
configuration class is arbitrary. In addition, a test class can contain more than one
`static` nested configuration class if desired.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@RunWith(SpringRunner.class)
	// ApplicationContext will be loaded from the
	// static nested Config class
	**@ContextConfiguration**
	public class OrderServiceTest {

		@Configuration
		static class Config {

			// this bean will be injected into the OrderServiceTest class
			@Bean
			public OrderService orderService() {
				OrderService orderService = new OrderServiceImpl();
				// set properties, etc.
				return orderService;
			}
		}

		@Autowired
		private OrderService orderService;

		@Test
		public void testOrderService() {
			// test the orderService
		}

	}
----

[[testcontext-ctx-management-mixed-config]]
===== Mixing XML, Groovy scripts, and annotated classes

It may sometimes be desirable to mix XML configuration files, Groovy scripts, and
annotated classes (i.e., typically `@Configuration` classes) to configure an
`ApplicationContext` for your tests. For example, if you use XML configuration in
production, you may decide that you want to use `@Configuration` classes to configure
specific Spring-managed components for your tests, or vice versa.

Furthermore, some third-party frameworks (like Spring Boot) provide first-class support
for loading an `ApplicationContext` from different types of resources simultaneously
(e.g., XML configuration files, Groovy scripts, and `@Configuration` classes). The Spring
Framework historically has not supported this for standard deployments. Consequently,
most of the `SmartContextLoader` implementations that the Spring Framework delivers in
the `spring-test` module support only one resource type per test context; however, this
does not mean that you cannot use both. One exception to the general rule is that the
`GenericGroovyXmlContextLoader` and `GenericGroovyXmlWebContextLoader` support both XML
configuration files and Groovy scripts simultaneously. Furthermore, third-party
frameworks may choose to support the declaration of both `locations` and `classes` via
`@ContextConfiguration`, and with the standard testing support in the TestContext
framework, you have the following options.

If you want to use resource locations (e.g., XML or Groovy) __and__ `@Configuration`
classes to configure your tests, you will have to pick one as the __entry point__, and
that one will have to include or import the other. For example, in XML or Groovy scripts
you can include `@Configuration` classes via component scanning or define them as normal
Spring beans; whereas, in a `@Configuration` class you can use `@ImportResource` to
import XML configuration files or Groovy scripts. Note that this behavior is semantically
equivalent to how you configure your application in production: in production
configuration you will define either a set of XML or Groovy resource locations or a set
of `@Configuration` classes that your production `ApplicationContext` will be loaded
from, but you still have the freedom to include or import the other type of configuration.

[[testcontext-ctx-management-initializers]]
===== Context configuration with context initializers

To configure an `ApplicationContext` for your tests using context initializers, annotate
your test class with `@ContextConfiguration` and configure the `initializers` attribute
with an array that contains references to classes that implement
`ApplicationContextInitializer`. The declared context initializers will then be used to
initialize the `ConfigurableApplicationContext` that is loaded for your tests. Note that
the concrete `ConfigurableApplicationContext` type supported by each declared
initializer must be compatible with the type of `ApplicationContext` created by the
`SmartContextLoader` in use (i.e., typically a `GenericApplicationContext`).
Furthermore, the order in which the initializers are invoked depends on whether they
implement Spring's `Ordered` interface or are annotated with Spring's `@Order` annotation
or the standard `@Priority` annotation.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@RunWith(SpringRunner.class)
	// ApplicationContext will be loaded from TestConfig
	// and initialized by TestAppCtxInitializer
	**@ContextConfiguration(
		classes = TestConfig.class,
		initializers = TestAppCtxInitializer.class)**
	public class MyTest {
		// class body...
	}
----

It is also possible to omit the declaration of XML configuration files, Groovy scripts,
or annotated classes in `@ContextConfiguration` entirely and instead declare only
`ApplicationContextInitializer` classes which are then responsible for registering beans
in the context -- for example, by programmatically loading bean definitions from XML
files or configuration classes.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@RunWith(SpringRunner.class)
	// ApplicationContext will be initialized by EntireAppInitializer
	// which presumably registers beans in the context
	**@ContextConfiguration(initializers = EntireAppInitializer.class)**
	public class MyTest {
		// class body...
	}
----

[[testcontext-ctx-management-inheritance]]
===== Context configuration inheritance

`@ContextConfiguration` supports boolean `inheritLocations` and `inheritInitializers`
attributes that denote whether resource locations or annotated classes and context
initializers declared by superclasses should be __inherited__. The default value for
both flags is `true`. This means that a test class inherits the resource locations or
annotated classes as well as the context initializers declared by any superclasses.
Specifically, the resource locations or annotated classes for a test class are appended
to the list of resource locations or annotated classes declared by superclasses.
Similarly, the initializers for a given test class will be added to the set of
initializers defined by test superclasses. Thus, subclasses have the option
of __extending__ the resource locations, annotated classes, or context initializers.

If the `inheritLocations` or `inheritInitializers` attribute in `@ContextConfiguration`
is set to `false`, the resource locations or annotated classes and the context
initializers, respectively, for the test class __shadow__ and effectively replace the
configuration defined by superclasses.

In the following example that uses XML resource locations, the `ApplicationContext` for
`ExtendedTest` will be loaded from __"base-config.xml"__ __and__
__"extended-config.xml"__, in that order. Beans defined in __"extended-config.xml"__ may
therefore __override__ (i.e., replace) those defined in __"base-config.xml"__.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@RunWith(SpringRunner.class)
	// ApplicationContext will be loaded from "/base-config.xml"
	// in the root of the classpath
	**@ContextConfiguration("/base-config.xml")**
	public class BaseTest {
		// class body...
	}

	// ApplicationContext will be loaded from "/base-config.xml" and
	// "/extended-config.xml" in the root of the classpath
	**@ContextConfiguration("/extended-config.xml")**
	public class ExtendedTest extends BaseTest {
		// class body...
	}
----

Similarly, in the following example that uses annotated classes, the
`ApplicationContext` for `ExtendedTest` will be loaded from the `BaseConfig` __and__
`ExtendedConfig` classes, in that order. Beans defined in `ExtendedConfig` may therefore
override (i.e., replace) those defined in `BaseConfig`.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@RunWith(SpringRunner.class)
	// ApplicationContext will be loaded from BaseConfig
	**@ContextConfiguration(classes = BaseConfig.class)**
	public class BaseTest {
		// class body...
	}

	// ApplicationContext will be loaded from BaseConfig and ExtendedConfig
	**@ContextConfiguration(classes = ExtendedConfig.class)**
	public class ExtendedTest extends BaseTest {
		// class body...
	}
----

In the following example that uses context initializers, the `ApplicationContext` for
`ExtendedTest` will be initialized using `BaseInitializer` __and__
`ExtendedInitializer`. Note, however, that the order in which the initializers are
invoked depends on whether they implement Spring's `Ordered` interface or are annotated
with Spring's `@Order` annotation or the standard `@Priority` annotation.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@RunWith(SpringRunner.class)
	// ApplicationContext will be initialized by BaseInitializer
	**@ContextConfiguration(initializers = BaseInitializer.class)**
	public class BaseTest {
		// class body...
	}

	// ApplicationContext will be initialized by BaseInitializer
	// and ExtendedInitializer
	**@ContextConfiguration(initializers = ExtendedInitializer.class)**
	public class ExtendedTest extends BaseTest {
		// class body...
	}
----

[[testcontext-ctx-management-env-profiles]]
===== Context configuration with environment profiles

Spring 3.1 introduced first-class support in the framework for the notion of
environments and profiles (a.k.a., __bean definition profiles__), and integration tests
can be configured to activate particular bean definition profiles for various testing
scenarios. This is achieved by annotating a test class with the `@ActiveProfiles`
annotation and supplying a list of profiles that should be activated when loading the
`ApplicationContext` for the test.

[NOTE]
====
`@ActiveProfiles` may be used with any implementation of the new `SmartContextLoader`
SPI, but `@ActiveProfiles` is not supported with implementations of the older
`ContextLoader` SPI.
====

Let's take a look at some examples with XML configuration and `@Configuration` classes.

[source,xml,indent=0]
[subs="verbatim,quotes"]
----
	<!-- app-config.xml -->
	<beans xmlns="http://www.springframework.org/schema/beans"
		xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
		xmlns:jdbc="http://www.springframework.org/schema/jdbc"
		xmlns:jee="http://www.springframework.org/schema/jee"
		xsi:schemaLocation="...">

		<bean id="transferService"
				class="com.bank.service.internal.DefaultTransferService">
			<constructor-arg ref="accountRepository"/>
			<constructor-arg ref="feePolicy"/>
		</bean>

		<bean id="accountRepository"
				class="com.bank.repository.internal.JdbcAccountRepository">
			<constructor-arg ref="dataSource"/>
		</bean>

		<bean id="feePolicy"
			class="com.bank.service.internal.ZeroFeePolicy"/>

		<beans profile="dev">
			<jdbc:embedded-database id="dataSource">
				<jdbc:script
					location="classpath:com/bank/config/sql/schema.sql"/>
				<jdbc:script
					location="classpath:com/bank/config/sql/test-data.sql"/>
			</jdbc:embedded-database>
		</beans>

		<beans profile="production">
			<jee:jndi-lookup id="dataSource" jndi-name="java:comp/env/jdbc/datasource"/>
		</beans>

		<beans profile="default">
			<jdbc:embedded-database id="dataSource">
				<jdbc:script
					location="classpath:com/bank/config/sql/schema.sql"/>
			</jdbc:embedded-database>
		</beans>

	</beans>
----

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	package com.bank.service;

	@RunWith(SpringRunner.class)
	// ApplicationContext will be loaded from "classpath:/app-config.xml"
	@ContextConfiguration("/app-config.xml")
	@ActiveProfiles("dev")
	public class TransferServiceTest {

		@Autowired
		private TransferService transferService;

		@Test
		public void testTransferService() {
			// test the transferService
		}
	}
----

When `TransferServiceTest` is run, its `ApplicationContext` will be loaded from the
`app-config.xml` configuration file in the root of the classpath. If you inspect
`app-config.xml` you'll notice that the `accountRepository` bean has a dependency on a
`dataSource` bean; however, `dataSource` is not defined as a top-level bean. Instead,
`dataSource` is defined three times: in the __production__ profile, the
__dev__ profile, and the __default__ profile.

By annotating `TransferServiceTest` with `@ActiveProfiles("dev")` we instruct the Spring
TestContext Framework to load the `ApplicationContext` with the active profiles set to
`{"dev"}`. As a result, an embedded database will be created and populated with test data,
and the `accountRepository` bean will be wired with a reference to the development
`DataSource`. And that's likely what we want in an integration test.

It is sometimes useful to assign beans to a `default` profile. Beans within the default profile
are only included when no other profile is specifically activated. This can be used to define
_fallback_ beans to be used in the application's default state. For example, you may
explicitly provide a data source for `dev` and `production` profiles, but define an in-memory
data source as a default when neither of these is active.

The following code listings demonstrate how to implement the same configuration and
integration test but using `@Configuration` classes instead of XML.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@Configuration
	@Profile("dev")
	public class StandaloneDataConfig {

		@Bean
		public DataSource dataSource() {
			return new EmbeddedDatabaseBuilder()
				.setType(EmbeddedDatabaseType.HSQL)
				.addScript("classpath:com/bank/config/sql/schema.sql")
				.addScript("classpath:com/bank/config/sql/test-data.sql")
				.build();
		}
	}
----

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@Configuration
	@Profile("production")
	public class JndiDataConfig {

		@Bean(destroyMethod="")
		public DataSource dataSource() throws Exception {
			Context ctx = new InitialContext();
			return (DataSource) ctx.lookup("java:comp/env/jdbc/datasource");
		}
	}
----

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@Configuration
	@Profile("default")
	public class DefaultDataConfig {

		@Bean
		public DataSource dataSource() {
			return new EmbeddedDatabaseBuilder()
				.setType(EmbeddedDatabaseType.HSQL)
				.addScript("classpath:com/bank/config/sql/schema.sql")
				.build();
		}
	}
----

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@Configuration
	public class TransferServiceConfig {

		@Autowired DataSource dataSource;

		@Bean
		public TransferService transferService() {
			return new DefaultTransferService(accountRepository(), feePolicy());
		}

		@Bean
		public AccountRepository accountRepository() {
			return new JdbcAccountRepository(dataSource);
		}

		@Bean
		public FeePolicy feePolicy() {
			return new ZeroFeePolicy();
		}

	}
----

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	package com.bank.service;

	@RunWith(SpringRunner.class)
	@ContextConfiguration(classes = {
			TransferServiceConfig.class,
			StandaloneDataConfig.class,
			JndiDataConfig.class,
			DefaultDataConfig.class})
	@ActiveProfiles("dev")
	public class TransferServiceTest {

		@Autowired
		private TransferService transferService;

		@Test
		public void testTransferService() {
			// test the transferService
		}
	}
----

In this variation, we have split the XML configuration into four independent
`@Configuration` classes:

* `TransferServiceConfig`: acquires a `dataSource` via dependency injection using
  `@Autowired`
* `StandaloneDataConfig`: defines a `dataSource` for an embedded database suitable for
  developer tests
* `JndiDataConfig`: defines a `dataSource` that is retrieved from JNDI in a production
  environment
* `DefaultDataConfig`: defines a `dataSource` for a default embedded database in case
  no profile is active

As with the XML-based configuration example, we still annotate `TransferServiceTest`
with `@ActiveProfiles("dev")`, but this time we specify all four configuration classes
via the `@ContextConfiguration` annotation. The body of the test class itself remains
completely unchanged.

It is often the case that a single set of profiles is used across multiple test classes
within a given project. Thus, to avoid duplicate declarations of the `@ActiveProfiles`
annotation it is possible to declare `@ActiveProfiles` once on a base class, and
subclasses will automatically inherit the `@ActiveProfiles` configuration from the base
class. In the following example, the declaration of `@ActiveProfiles` (as well as other
annotations) has been moved to an abstract superclass, `AbstractIntegrationTest`.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	package com.bank.service;

	@RunWith(SpringRunner.class)
	@ContextConfiguration(classes = {
			TransferServiceConfig.class,
			StandaloneDataConfig.class,
			JndiDataConfig.class,
			DefaultDataConfig.class})
	@ActiveProfiles("dev")
	public abstract class AbstractIntegrationTest {
	}
----

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	package com.bank.service;

	// "dev" profile inherited from superclass
	public class TransferServiceTest extends AbstractIntegrationTest {

		@Autowired
		private TransferService transferService;

		@Test
		public void testTransferService() {
			// test the transferService
		}
	}
----

`@ActiveProfiles` also supports an `inheritProfiles` attribute that can be used to
disable the inheritance of active profiles.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	package com.bank.service;

	// "dev" profile overridden with "production"
	@ActiveProfiles(profiles = "production", inheritProfiles = false)
	public class ProductionTransferServiceTest extends AbstractIntegrationTest {
		// test body
	}
----

[[testcontext-ctx-management-env-profiles-ActiveProfilesResolver]]
Furthermore, it is sometimes necessary to resolve active profiles for tests
__programmatically__ instead of declaratively -- for example, based on:

* the current operating system
* whether tests are being executed on a continuous integration build server
* the presence of certain environment variables
* the presence of custom class-level annotations
* etc.

To resolve active bean definition profiles programmatically, simply implement a custom
`ActiveProfilesResolver` and register it via the `resolver` attribute of
`@ActiveProfiles`. The following example demonstrates how to implement and register a
custom `OperatingSystemActiveProfilesResolver`. For further information, refer to the
corresponding javadocs.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	package com.bank.service;

	// "dev" profile overridden programmatically via a custom resolver
	@ActiveProfiles(
		resolver = OperatingSystemActiveProfilesResolver.class,
		inheritProfiles = false)
	public class TransferServiceTest extends AbstractIntegrationTest {
		// test body
	}
----

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	package com.bank.service.test;

	public class OperatingSystemActiveProfilesResolver implements ActiveProfilesResolver {

		@Override
		String[] resolve(Class<?> testClass) {
			String profile = ...;
			// determine the value of profile based on the operating system
			return new String[] {profile};
		}
	}
----

[[testcontext-ctx-management-property-sources]]
===== Context configuration with test property sources

Spring 3.1 introduced first-class support in the framework for the notion of an
environment with a hierarchy of _property sources_, and since Spring 4.1 integration
tests can be configured with test-specific property sources. In contrast to the
`@PropertySource` annotation used on `@Configuration` classes, the `@TestPropertySource`
annotation can be declared on a test class to declare resource locations for test
properties files or _inlined_ properties. These test property sources will be added to
the set of `PropertySources` in the `Environment` for the `ApplicationContext` loaded
for the annotated integration test.

[NOTE]
====
`@TestPropertySource` may be used with any implementation of the `SmartContextLoader`
SPI, but `@TestPropertySource` is not supported with implementations of the older
`ContextLoader` SPI.

Implementations of `SmartContextLoader` gain access to merged test property source values
via the `getPropertySourceLocations()` and `getPropertySourceProperties()` methods in
`MergedContextConfiguration`.
====

*Declaring test property sources*

Test properties files can be configured via the `locations` or `value` attribute of
`@TestPropertySource` as shown in the following example.

Both traditional and XML-based properties file formats are supported -- for example,
`"classpath:/com/example/test.properties"` or `"file:///path/to/file.xml"`.

Each path will be interpreted as a Spring `Resource`. A plain path -- for example,
`"test.properties"` -- will be treated as a classpath resource that is _relative_ to the
package in which the test class is defined. A path starting with a slash will be treated
as an _absolute_ classpath resource, for example: `"/org/example/test.xml"`. A path which
references a URL (e.g., a path prefixed with `classpath:`, `file:`, `http:`, etc.) will
be loaded using the specified resource protocol. Resource location wildcards (e.g.
`**/*.properties`) are not permitted: each location must evaluate to exactly one
`.properties` or `.xml` resource.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@ContextConfiguration
	@TestPropertySource("/test.properties")
	public class MyIntegrationTests {
		// class body...
	}
----

_Inlined_ properties in the form of key-value pairs can be configured via the
`properties` attribute of `@TestPropertySource` as shown in the following example. All
key-value pairs will be added to the enclosing `Environment` as a single test
`PropertySource` with the highest precedence.

The supported syntax for key-value pairs is the same as the syntax defined for entries in
a Java properties file:

* `"key=value"`
* `"key:value"`
* `"key value"`

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@ContextConfiguration
	@TestPropertySource(properties = {"timezone = GMT", "port: 4242"})
	public class MyIntegrationTests {
		// class body...
	}
----

*Default properties file detection*

If `@TestPropertySource` is declared as an empty annotation (i.e., without explicit
values for the `locations` or `properties` attributes), an attempt will be made to detect
a _default_ properties file relative to the class that declared the annotation. For
example, if the annotated test class is `com.example.MyTest`, the corresponding default
properties file is `"classpath:com/example/MyTest.properties"`. If the default cannot be
detected, an `IllegalStateException` will be thrown.

*Precedence*

Test property sources have higher precedence than those loaded from the operating
system's environment or Java system properties as well as property sources added by the
application declaratively via `@PropertySource` or programmatically. Thus, test property
sources can be used to selectively override properties defined in system and application
property sources. Furthermore, inlined properties have higher precedence than properties
loaded from resource locations.

In the following example, the `timezone` and `port` properties as well as any properties
defined in `"/test.properties"` will override any properties of the same name that are
defined in system and application property sources. Furthermore, if the
`"/test.properties"` file defines entries for the `timezone` and `port` properties those
will be overridden by the _inlined_ properties declared via the `properties` attribute.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@ContextConfiguration
	@TestPropertySource(
		locations = "/test.properties",
		properties = {"timezone = GMT", "port: 4242"}
	)
	public class MyIntegrationTests {
		// class body...
	}
----

*Inheriting and overriding test property sources*

`@TestPropertySource` supports boolean `inheritLocations` and `inheritProperties`
attributes that denote whether resource locations for properties files and inlined
properties declared by superclasses should be __inherited__. The default value for both
flags is `true`. This means that a test class inherits the locations and inlined
properties declared by any superclasses. Specifically, the locations and inlined
properties for a test class are appended to the locations and inlined properties declared
by superclasses. Thus, subclasses have the option of __extending__ the locations and
inlined properties. Note that properties that appear later will __shadow__ (i.e..,
override) properties of the same name that appear earlier. In addition, the
aforementioned precedence rules apply for inherited test property sources as well.

If the `inheritLocations` or `inheritProperties` attribute in `@TestPropertySource` is set
to `false`, the locations or inlined properties, respectively, for the test class __shadow__
and effectively replace the configuration defined by superclasses.

In the following example, the `ApplicationContext` for `BaseTest` will be loaded using
only the `"base.properties"` file as a test property source. In contrast, the
`ApplicationContext` for `ExtendedTest` will be loaded using the `"base.properties"`
**and** `"extended.properties"` files as test property source locations.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@TestPropertySource("base.properties")
	@ContextConfiguration
	public class BaseTest {
		// ...
	}

	@TestPropertySource("extended.properties")
	@ContextConfiguration
	public class ExtendedTest extends BaseTest {
		// ...
	}
----

In the following example, the `ApplicationContext` for `BaseTest` will be loaded using only
the _inlined_ `key1` property. In contrast, the `ApplicationContext` for `ExtendedTest` will be
loaded using the _inlined_ `key1` and `key2` properties.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@TestPropertySource(properties = "key1 = value1")
	@ContextConfiguration
	public class BaseTest {
		// ...
	}

	@TestPropertySource(properties = "key2 = value2")
	@ContextConfiguration
	public class ExtendedTest extends BaseTest {
		// ...
	}
----

[[testcontext-ctx-management-web]]
===== Loading a WebApplicationContext

Spring 3.2 introduced support for loading a `WebApplicationContext` in integration
tests. To instruct the TestContext framework to load a `WebApplicationContext` instead
of a standard `ApplicationContext`, simply annotate the respective test class with
`@WebAppConfiguration`.

The presence of `@WebAppConfiguration` on your test class instructs the TestContext
framework (TCF) that a `WebApplicationContext` (WAC) should be loaded for your
integration tests. In the background the TCF makes sure that a `MockServletContext` is
created and supplied to your test's WAC. By default the base resource path for your
`MockServletContext` will be set to __"src/main/webapp"__. This is interpreted as a path
relative to the root of your JVM (i.e., normally the path to your project). If you're
familiar with the directory structure of a web application in a Maven project, you'll
know that __"src/main/webapp"__ is the default location for the root of your WAR. If you
need to override this default, simply provide an alternate path to the
`@WebAppConfiguration` annotation (e.g., `@WebAppConfiguration("src/test/webapp")`). If
you wish to reference a base resource path from the classpath instead of the file
system, just use Spring's __classpath:__ prefix.

Please note that Spring's testing support for `WebApplicationContexts` is on par with its
support for standard `ApplicationContexts`. When testing with a `WebApplicationContext`
you are free to declare XML configuration files, Groovy scripts, or `@Configuration`
classes via `@ContextConfiguration`. You are of course also free to use any other test
annotations such as `@ActiveProfiles`, `@TestExecutionListeners`, `@Sql`, `@Rollback`,
etc.

The following examples demonstrate some of the various configuration options for loading
a `WebApplicationContext`.

.Conventions
[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@RunWith(SpringRunner.class)

	// defaults to "file:src/main/webapp"
	@WebAppConfiguration

	// detects "WacTests-context.xml" in same package
	// or static nested @Configuration class
	@ContextConfiguration

	public class WacTests {
		//...
	}
----

The above example demonstrates the TestContext framework's support for __convention over
configuration__. If you annotate a test class with `@WebAppConfiguration` without
specifying a resource base path, the resource path will effectively default
to __"file:src/main/webapp"__. Similarly, if you declare `@ContextConfiguration` without
specifying resource `locations`, annotated `classes`, or context `initializers`, Spring
will attempt to detect the presence of your configuration using conventions
(i.e., __"WacTests-context.xml"__ in the same package as the `WacTests` class or static
nested `@Configuration` classes).

.Default resource semantics
[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@RunWith(SpringRunner.class)

	// file system resource
	@WebAppConfiguration("webapp")

	// classpath resource
	@ContextConfiguration("/spring/test-servlet-config.xml")

	public class WacTests {
		//...
	}
----

This example demonstrates how to explicitly declare a resource base path with
`@WebAppConfiguration` and an XML resource location with `@ContextConfiguration`. The
important thing to note here is the different semantics for paths with these two
annotations. By default, `@WebAppConfiguration` resource paths are file system based;
whereas, `@ContextConfiguration` resource locations are classpath based.

.Explicit resource semantics
[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@RunWith(SpringRunner.class)

	// classpath resource
	@WebAppConfiguration("classpath:test-web-resources")

	// file system resource
	@ContextConfiguration("file:src/main/webapp/WEB-INF/servlet-config.xml")

	public class WacTests {
		//...
	}
----

In this third example, we see that we can override the default resource semantics for
both annotations by specifying a Spring resource prefix. Contrast the comments in this
example with the previous example.

.[[testcontext-ctx-management-web-mocks]]Working with Web Mocks
--
To provide comprehensive web testing support, Spring 3.2 introduced a
`ServletTestExecutionListener` that is enabled by default. When testing against a
`WebApplicationContext` this <<testcontext-key-abstractions,TestExecutionListener>> sets
up default thread-local state via Spring Web's `RequestContextHolder` before each test
method and creates a `MockHttpServletRequest`, `MockHttpServletResponse`, and
`ServletWebRequest` based on the base resource path configured via
`@WebAppConfiguration`. `ServletTestExecutionListener` also ensures that the
`MockHttpServletResponse` and `ServletWebRequest` can be injected into the test
instance, and once the test is complete it cleans up thread-local state.

Once you have a `WebApplicationContext` loaded for your test you might find that you
need to interact with the web mocks -- for example, to set up your test fixture or to
perform assertions after invoking your web component. The following example demonstrates
which mocks can be autowired into your test instance. Note that the
`WebApplicationContext` and `MockServletContext` are both cached across the test suite;
whereas, the other mocks are managed per test method by the
`ServletTestExecutionListener`.

.Injecting mocks
[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@WebAppConfiguration
	@ContextConfiguration
	public class WacTests {

		@Autowired
		WebApplicationContext wac; // cached

		@Autowired
		MockServletContext servletContext; // cached

		@Autowired
		MockHttpSession session;

		@Autowired
		MockHttpServletRequest request;

		@Autowired
		MockHttpServletResponse response;

		@Autowired
		ServletWebRequest webRequest;

		//...
	}
----
--

[[testcontext-ctx-management-caching]]
===== Context caching

Once the TestContext framework loads an `ApplicationContext` (or `WebApplicationContext`)
for a test, that context will be cached and reused for __all__ subsequent tests that
declare the same unique context configuration within the same test suite. To understand
how caching works, it is important to understand what is meant by __unique__ and __test
suite__.

An `ApplicationContext` can be __uniquely__ identified by the combination of
configuration parameters that are used to load it. Consequently, the unique combination
of configuration parameters are used to generate a __key__ under which the context is
cached. The TestContext framework uses the following configuration parameters to build
the context cache key:

* `locations` __(from @ContextConfiguration)__
* `classes` __(from @ContextConfiguration)__
* `contextInitializerClasses` __(from @ContextConfiguration)__
* `contextCustomizers` __(from ContextCustomizerFactory)__
* `contextLoader` __(from @ContextConfiguration)__
* `parent` __(from @ContextHierarchy)__
* `activeProfiles` __(from @ActiveProfiles)__
* `propertySourceLocations` __(from @TestPropertySource)__
* `propertySourceProperties` __(from @TestPropertySource)__
* `resourceBasePath` __(from @WebAppConfiguration)__

For example, if `TestClassA` specifies `{"app-config.xml", "test-config.xml"}` for the
`locations` (or `value`) attribute of `@ContextConfiguration`, the TestContext framework
will load the corresponding `ApplicationContext` and store it in a `static` context cache
under a key that is based solely on those locations. So if `TestClassB` also defines
`{"app-config.xml", "test-config.xml"}` for its locations (either explicitly or
implicitly through inheritance) but does not define `@WebAppConfiguration`, a different
`ContextLoader`, different active profiles, different context initializers, different
test property sources, or a different parent context, then the same `ApplicationContext`
will be shared by both test classes. This means that the setup cost for loading an
application context is incurred only once (per test suite), and subsequent test execution
is much faster.

.Test suites and forked processes
[NOTE]
====
The Spring TestContext framework stores application contexts in a __static__ cache. This
means that the context is literally stored in a `static` variable. In other words, if
tests execute in separate processes the static cache will be cleared between each test
execution, and this will effectively disable the caching mechanism.

To benefit from the caching mechanism, all tests must run within the same process or
test suite. This can be achieved by executing all tests as a group within an IDE.
Similarly, when executing tests with a build framework such as Ant, Maven, or Gradle it
is important to make sure that the build framework does not __fork__ between tests. For
example, if the
https://maven.apache.org/plugins/maven-surefire-plugin/test-mojo.html#forkMode[forkMode]
for the Maven Surefire plug-in is set to `always` or `pertest`, the TestContext
framework will not be able to cache application contexts between test classes and the
build process will run significantly slower as a result.
====

Since Spring Framework 4.3, the size of the context cache is bounded with a default
maximum size of 32. Whenever the maximum size is reached, a _least recently used_ (LRU)
eviction policy is used to evict and close stale contexts. The maximum size can be
configured from the command line or a build script by setting a JVM system property named
`spring.test.context.cache.maxSize`. As an alternative, the same property can be set
programmatically via the `SpringProperties` API.

Since having a large number of application contexts loaded within a given test suite can
cause the suite to take an unnecessarily long time to execute, it is often beneficial to
know exactly how many contexts have been loaded and cached. To view the statistics for
the underlying context cache, simply set the log level for the
`org.springframework.test.context.cache` logging category to `DEBUG`.

In the unlikely case that a test corrupts the application context and requires reloading
-- for example, by modifying a bean definition or the state of an application object --
you can annotate your test class or test method with `@DirtiesContext` (see the
discussion of `@DirtiesContext` in <<integration-testing-annotations-spring>>). This
instructs Spring to remove the context from the cache and rebuild the application
context before executing the next test. Note that support for the `@DirtiesContext`
annotation is provided by the `DirtiesContextBeforeModesTestExecutionListener` and the
`DirtiesContextTestExecutionListener` which are enabled by default.


[[testcontext-ctx-management-ctx-hierarchies]]
===== Context hierarchies

When writing integration tests that rely on a loaded Spring `ApplicationContext`, it is
often sufficient to test against a single context; however, there are times when it is
beneficial or even necessary to test against a hierarchy of ``ApplicationContext``s. For
example, if you are developing a Spring MVC web application you will typically have a
root `WebApplicationContext` loaded via Spring's `ContextLoaderListener` and a child
`WebApplicationContext` loaded via Spring's `DispatcherServlet`. This results in a
parent-child context hierarchy where shared components and infrastructure configuration
are declared in the root context and consumed in the child context by web-specific
components. Another use case can be found in Spring Batch applications where you often
have a parent context that provides configuration for shared batch infrastructure and a
child context for the configuration of a specific batch job.

Since Spring Framework 3.2.2, it is possible to write integration tests that use context
hierarchies by declaring context configuration via the `@ContextHierarchy` annotation,
either on an individual test class or within a test class hierarchy. If a context
hierarchy is declared on multiple classes within a test class hierarchy it is also
possible to merge or override the context configuration for a specific, named level in
the context hierarchy. When merging configuration for a given level in the hierarchy the
configuration resource type (i.e., XML configuration files or annotated classes) must be
consistent; otherwise, it is perfectly acceptable to have different levels in a context
hierarchy configured using different resource types.

The following JUnit 4 based examples demonstrate common configuration scenarios for
integration tests that require the use of context hierarchies.

.Single test class with context hierarchy
--
`ControllerIntegrationTests` represents a typical integration testing scenario for a
Spring MVC web application by declaring a context hierarchy consisting of two levels,
one for the __root__ WebApplicationContext (loaded using the `TestAppConfig`
`@Configuration` class) and one for the __dispatcher servlet__ `WebApplicationContext`
(loaded using the `WebConfig` `@Configuration` class). The `WebApplicationContext` that
is __autowired__ into the test instance is the one for the child context (i.e., the
lowest context in the hierarchy).

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@RunWith(SpringRunner.class)
	@WebAppConfiguration
	@ContextHierarchy({
		@ContextConfiguration(classes = TestAppConfig.class),
		@ContextConfiguration(classes = WebConfig.class)
	})
	public class ControllerIntegrationTests {

		@Autowired
		private WebApplicationContext wac;

		// ...
	}
----

--


.Class hierarchy with implicit parent context
--
The following test classes define a context hierarchy within a test class hierarchy.
`AbstractWebTests` declares the configuration for a root `WebApplicationContext` in a
Spring-powered web application. Note, however, that `AbstractWebTests` does not declare
`@ContextHierarchy`; consequently, subclasses of `AbstractWebTests` can optionally
participate in a context hierarchy or simply follow the standard semantics for
`@ContextConfiguration`. `SoapWebServiceTests` and `RestWebServiceTests` both extend
`AbstractWebTests` and define a context hierarchy via `@ContextHierarchy`. The result is
that three application contexts will be loaded (one for each declaration of
`@ContextConfiguration`), and the application context loaded based on the configuration
in `AbstractWebTests` will be set as the parent context for each of the contexts loaded
for the concrete subclasses.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@RunWith(SpringRunner.class)
	@WebAppConfiguration
	@ContextConfiguration("file:src/main/webapp/WEB-INF/applicationContext.xml")
	public abstract class AbstractWebTests {}

	@ContextHierarchy(@ContextConfiguration("/spring/soap-ws-config.xml")
	public class SoapWebServiceTests extends AbstractWebTests {}

	@ContextHierarchy(@ContextConfiguration("/spring/rest-ws-config.xml")
	public class RestWebServiceTests extends AbstractWebTests {}
----
--


.Class hierarchy with merged context hierarchy configuration
--
The following classes demonstrate the use of __named__ hierarchy levels in order to
__merge__ the configuration for specific levels in a context hierarchy. `BaseTests`
defines two levels in the hierarchy, `parent` and `child`. `ExtendedTests` extends
`BaseTests` and instructs the Spring TestContext Framework to merge the context
configuration for the `child` hierarchy level, simply by ensuring that the names
declared via the `name` attribute in `@ContextConfiguration` are both `"child"`. The
result is that three application contexts will be loaded: one for `"/app-config.xml"`,
one for `"/user-config.xml"`, and one for `{"/user-config.xml", "/order-config.xml"}`.
As with the previous example, the application context loaded from `"/app-config.xml"`
will be set as the parent context for the contexts loaded from `"/user-config.xml"`
and `{"/user-config.xml", "/order-config.xml"}`.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@RunWith(SpringRunner.class)
	@ContextHierarchy({
		@ContextConfiguration(name = "parent", locations = "/app-config.xml"),
		@ContextConfiguration(name = "child", locations = "/user-config.xml")
	})
	public class BaseTests {}

	@ContextHierarchy(
		@ContextConfiguration(name = "child", locations = "/order-config.xml")
	)
	public class ExtendedTests extends BaseTests {}
----
--

.Class hierarchy with overridden context hierarchy configuration
--
In contrast to the previous example, this example demonstrates how to __override__ the
configuration for a given named level in a context hierarchy by setting the
`inheritLocations` flag in `@ContextConfiguration` to `false`. Consequently, the
application context for `ExtendedTests` will be loaded only from
`"/test-user-config.xml"` and will have its parent set to the context loaded from
`"/app-config.xml"`.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@RunWith(SpringRunner.class)
	@ContextHierarchy({
		@ContextConfiguration(name = "parent", locations = "/app-config.xml"),
		@ContextConfiguration(name = "child", locations = "/user-config.xml")
	})
	public class BaseTests {}

	@ContextHierarchy(
		@ContextConfiguration(
			name = "child",
			locations = "/test-user-config.xml",
			inheritLocations = false
	))
	public class ExtendedTests extends BaseTests {}
----

.Dirtying a context within a context hierarchy
[NOTE]
====
If `@DirtiesContext` is used in a test whose context is configured as part of a context
hierarchy, the `hierarchyMode` flag can be used to control how the context cache is
cleared. For further details consult the discussion of `@DirtiesContext` in
<<integration-testing-annotations-spring,Spring Testing Annotations>> and the
`@DirtiesContext` javadocs.
====
--


[[testcontext-fixture-di]]
==== Dependency injection of test fixtures

When you use the `DependencyInjectionTestExecutionListener` -- which is configured by
default -- the dependencies of your test instances are __injected__ from beans in the
application context that you configured with `@ContextConfiguration`. You may use setter
injection, field injection, or both, depending on which annotations you choose and
whether you place them on setter methods or fields. For consistency with the annotation
support introduced in Spring 2.5 and 3.0, you can use Spring's `@Autowired` annotation
or the `@Inject` annotation from JSR 330.

[TIP]
====

The TestContext framework does not instrument the manner in which a test instance is
instantiated. Thus the use of `@Autowired` or `@Inject` for constructors has no effect
for test classes.
====

Because `@Autowired` is used to perform <<beans-factory-autowire, __autowiring by type__
>>, if you have multiple bean definitions of the same type, you cannot rely on this
approach for those particular beans. In that case, you can use `@Autowired` in
conjunction with `@Qualifier`. As of Spring 3.0 you may also choose to use `@Inject` in
conjunction with `@Named`. Alternatively, if your test class has access to its
`ApplicationContext`, you can perform an explicit lookup by using (for example) a call
to `applicationContext.getBean("titleRepository")`.

If you do not want dependency injection applied to your test instances, simply do not
annotate fields or setter methods with `@Autowired` or `@Inject`. Alternatively, you can
disable dependency injection altogether by explicitly configuring your class with
`@TestExecutionListeners` and omitting `DependencyInjectionTestExecutionListener.class`
from the list of listeners.

Consider the scenario of testing a `HibernateTitleRepository` class, as outlined in the
<<integration-testing-goals,Goals>> section. The next two code listings demonstrate the
use of `@Autowired` on fields and setter methods. The application context configuration
is presented after all sample code listings.

[NOTE]
====
The dependency injection behavior in the following code listings is not specific to
JUnit 4. The same DI techniques can be used in conjunction with any testing framework.

The following examples make calls to static assertion methods such as `assertNotNull()`
but without prepending the call with `Assert`. In such cases, assume that the method was
properly imported through an `import static` declaration that is not shown in the
example.
====

The first code listing shows a JUnit 4 based implementation of the test class that uses
`@Autowired` for field injection.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@RunWith(SpringRunner.class)
	// specifies the Spring configuration to load for this test fixture
	**@ContextConfiguration("repository-config.xml")**
	public class HibernateTitleRepositoryTests {

		// this instance will be dependency injected by type
		**@Autowired**
		private HibernateTitleRepository titleRepository;

		@Test
		public void findById() {
			Title title = titleRepository.findById(new Long(10));
			assertNotNull(title);
		}
	}
----

Alternatively, you can configure the class to use `@Autowired` for setter injection as
seen below.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@RunWith(SpringRunner.class)
	// specifies the Spring configuration to load for this test fixture
	**@ContextConfiguration("repository-config.xml")**
	public class HibernateTitleRepositoryTests {

		// this instance will be dependency injected by type
		private HibernateTitleRepository titleRepository;

		**@Autowired**
		public void setTitleRepository(HibernateTitleRepository titleRepository) {
			this.titleRepository = titleRepository;
		}

		@Test
		public void findById() {
			Title title = titleRepository.findById(new Long(10));
			assertNotNull(title);
		}
	}
----

The preceding code listings use the same XML context file referenced by the
`@ContextConfiguration` annotation (that is, `repository-config.xml`), which looks like
this:

[source,xml,indent=0]
[subs="verbatim,quotes"]
----
	<?xml version="1.0" encoding="UTF-8"?>
	<beans xmlns="http://www.springframework.org/schema/beans"
		xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
		xsi:schemaLocation="http://www.springframework.org/schema/beans
			https://www.springframework.org/schema/beans/spring-beans.xsd">

		<!-- this bean will be injected into the HibernateTitleRepositoryTests class -->
		<bean id="**titleRepository**" class="**com.foo.repository.hibernate.HibernateTitleRepository**">
			<property name="sessionFactory" ref="sessionFactory"/>
		</bean>

		<bean id="sessionFactory" class="org.springframework.orm.hibernate5.LocalSessionFactoryBean">
			<!-- configuration elided for brevity -->
		</bean>

	</beans>
----

[NOTE]
====
If you are extending from a Spring-provided test base class that happens to use
`@Autowired` on one of its setter methods, you might have multiple beans of the affected
type defined in your application context: for example, multiple `DataSource` beans. In
such a case, you can override the setter method and use the `@Qualifier` annotation to
indicate a specific target bean as follows, but make sure to delegate to the overridden
method in the superclass as well.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	// ...

		@Autowired
		@Override
		public void setDataSource(**@Qualifier("myDataSource")** DataSource dataSource) {
			**super**.setDataSource(dataSource);
		}

	// ...
----

The specified qualifier value indicates the specific `DataSource` bean to inject,
narrowing the set of type matches to a specific bean. Its value is matched against
`<qualifier>` declarations within the corresponding `<bean>` definitions. The bean name
is used as a fallback qualifier value, so you may effectively also point to a specific
bean by name there (as shown above, assuming that "myDataSource" is the bean id).
====


[[testcontext-web-scoped-beans]]
==== Testing request and session scoped beans

<<beans-factory-scopes-other,Request and session scoped beans>> have been supported by
Spring since the early years, and since Spring 3.2 it's a breeze to test your
request-scoped and session-scoped beans by following these steps.

* Ensure that a `WebApplicationContext` is loaded for your test by annotating your test
  class with `@WebAppConfiguration`.
* Inject the mock request or session into your test instance and prepare your test
  fixture as appropriate.
* Invoke your web component that you retrieved from the configured
  `WebApplicationContext` (i.e., via dependency injection).
* Perform assertions against the mocks.

The following code snippet displays the XML configuration for a login use case. Note
that the `userService` bean has a dependency on a request-scoped `loginAction` bean.
Also, the `LoginAction` is instantiated using <<expressions,SpEL expressions>> that
retrieve the username and password from the current HTTP request. In our test, we will
want to configure these request parameters via the mock managed by the TestContext
framework.

.Request-scoped bean configuration
[source,xml,indent=0]
----
	<beans>

		<bean id="userService"
				class="com.example.SimpleUserService"
				c:loginAction-ref="loginAction" />

		<bean id="loginAction" class="com.example.LoginAction"
				c:username="#{request.getParameter('user')}"
				c:password="#{request.getParameter('pswd')}"
				scope="request">
			<aop:scoped-proxy />
		</bean>

	</beans>
----

In `RequestScopedBeanTests` we inject both the `UserService` (i.e., the subject under
test) and the `MockHttpServletRequest` into our test instance. Within our
`requestScope()` test method we set up our test fixture by setting request parameters in
the provided `MockHttpServletRequest`. When the `loginUser()` method is invoked on our
`userService` we are assured that the user service has access to the request-scoped
`loginAction` for the current `MockHttpServletRequest` (i.e., the one we just set
parameters in). We can then perform assertions against the results based on the known
inputs for the username and password.

.Request-scoped bean test
[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@RunWith(SpringRunner.class)
	@ContextConfiguration
	@WebAppConfiguration
	public class RequestScopedBeanTests {

		@Autowired UserService userService;
		@Autowired MockHttpServletRequest request;

		@Test
		public void requestScope() {

			request.setParameter("user", "enigma");
			request.setParameter("pswd", "$pr!ng");

			LoginResults results = userService.loginUser();

			// assert results
		}
	}
----

The following code snippet is similar to the one we saw above for a request-scoped bean;
however, this time the `userService` bean has a dependency on a session-scoped
`userPreferences` bean. Note that the `UserPreferences` bean is instantiated using a
SpEL expression that retrieves the __theme__ from the current HTTP session. In our test,
we will need to configure a theme in the mock session managed by the TestContext
framework.

.Session-scoped bean configuration
[source,xml,indent=0]
[subs="verbatim,quotes"]
----
	<beans>

		<bean id="userService"
				class="com.example.SimpleUserService"
				c:userPreferences-ref="userPreferences" />

		<bean id="userPreferences"
				class="com.example.UserPreferences"
				c:theme="#{session.getAttribute('theme')}"
				scope="session">
			<aop:scoped-proxy />
		</bean>

	</beans>
----

In `SessionScopedBeanTests` we inject the `UserService` and the `MockHttpSession` into
our test instance. Within our `sessionScope()` test method we set up our test fixture by
setting the expected "theme" attribute in the provided `MockHttpSession`. When the
`processUserPreferences()` method is invoked on our `userService` we are assured that
the user service has access to the session-scoped `userPreferences` for the current
`MockHttpSession`, and we can perform assertions against the results based on the
configured theme.

.Session-scoped bean test
[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@RunWith(SpringRunner.class)
	@ContextConfiguration
	@WebAppConfiguration
	public class SessionScopedBeanTests {

		@Autowired UserService userService;
		@Autowired MockHttpSession session;

		@Test
		public void sessionScope() throws Exception {

			session.setAttribute("theme", "blue");

			Results results = userService.processUserPreferences();

			// assert results
		}
	}
----


[[testcontext-tx]]
==== Transaction management

In the TestContext framework, transactions are managed by the
`TransactionalTestExecutionListener` which is configured by default, even if you do not
explicitly declare `@TestExecutionListeners` on your test class. To enable support for
transactions, however, you must configure a `PlatformTransactionManager` bean in the
`ApplicationContext` that is loaded via `@ContextConfiguration` semantics (further
details are provided below). In addition, you must declare Spring's `@Transactional`
annotation either at the class or method level for your tests.

[[testcontext-tx-test-managed-transactions]]
===== Test-managed transactions

_Test-managed transactions_ are transactions that are managed _declaratively_ via the
`TransactionalTestExecutionListener` or _programmatically_ via `TestTransaction` (see
below). Such transactions should not be confused with _Spring-managed transactions_
(i.e., those managed directly by Spring within the `ApplicationContext` loaded for tests)
or _application-managed transactions_ (i.e., those managed programmatically within
application code that is invoked via tests). Spring-managed and application-managed
transactions will typically participate in test-managed transactions; however, caution
should be taken if Spring-managed or application-managed transactions are configured with
any _propagation_ type other than `REQUIRED` or `SUPPORTS` (see the discussion on
<<tx-propagation,transaction propagation>> for details).

[[testcontext-tx-enabling-transactions]]
===== Enabling and disabling transactions

Annotating a test method with `@Transactional` causes the test to be run within a
transaction that will, by default, be automatically rolled back after completion of the
test. If a test class is annotated with `@Transactional`, each test method within that
class hierarchy will be run within a transaction. Test methods that are not annotated
with `@Transactional` (at the class or method level) will not be run within a
transaction. Furthermore, tests that are annotated with `@Transactional` but have the
`propagation` type set to `NOT_SUPPORTED` will not be run within a transaction.

__Note that <<testcontext-support-classes-junit4,
`AbstractTransactionalJUnit4SpringContextTests`>> and
<<testcontext-support-classes-testng, `AbstractTransactionalTestNGSpringContextTests`>>
are preconfigured for transactional support at the class level.__

The following example demonstrates a common scenario for writing an integration test for
a Hibernate-based `UserRepository`. As explained in
<<testcontext-tx-rollback-and-commit-behavior>>, there is no need to clean up the
database after the `createUser()` method is executed since any changes made to the
database will be automatically rolled back by the `TransactionalTestExecutionListener`.
See <<testing-examples-petclinic>> for an additional example.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@RunWith(SpringRunner.class)
	@ContextConfiguration(classes = TestConfig.class)
	@Transactional
	public class HibernateUserRepositoryTests {

		@Autowired
		HibernateUserRepository repository;

		@Autowired
		SessionFactory sessionFactory;

		JdbcTemplate jdbcTemplate;

		@Autowired
		public void setDataSource(DataSource dataSource) {
			this.jdbcTemplate = new JdbcTemplate(dataSource);
		}

		@Test
		public void createUser() {
			// track initial state in test database:
			final int count = countRowsInTable("user");

			User user = new User(...);
			repository.save(user);

			// Manual flush is required to avoid false positive in test
			sessionFactory.getCurrentSession().flush();
			assertNumUsers(count + 1);
		}

		protected int countRowsInTable(String tableName) {
			return JdbcTestUtils.countRowsInTable(this.jdbcTemplate, tableName);
		}

		protected void assertNumUsers(int expected) {
			assertEquals("Number of rows in the [user] table.", expected, countRowsInTable("user"));
		}
	}
----

[[testcontext-tx-rollback-and-commit-behavior]]
===== Transaction rollback and commit behavior

By default, test transactions will be automatically rolled back after completion of the
test; however, transactional commit and rollback behavior can be configured declaratively
via the `@Commit` and `@Rollback` annotations. See the corresponding entries in the
<<integration-testing-annotations,annotation support>> section for further details.

[[testcontext-tx-programmatic-tx-mgt]]
===== Programmatic transaction management

Since Spring Framework 4.1, it is possible to interact with test-managed transactions
_programmatically_ via the static methods in `TestTransaction`. For example,
`TestTransaction` may be used within _test_ methods, _before_ methods, and _after_
methods to start or end the current test-managed transaction or to configure the current
test-managed transaction for rollback or commit. Support for `TestTransaction` is
automatically available whenever the `TransactionalTestExecutionListener` is enabled.

The following example demonstrates some of the features of `TestTransaction`. Consult the
javadocs for `TestTransaction` for further details.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@ContextConfiguration(classes = TestConfig.class)
	public class ProgrammaticTransactionManagementTests extends
			AbstractTransactionalJUnit4SpringContextTests {

		@Test
		public void transactionalTest() {
			// assert initial state in test database:
			assertNumUsers(2);

			deleteFromTables("user");

			// changes to the database will be committed!
			TestTransaction.flagForCommit();
			TestTransaction.end();
			assertFalse(TestTransaction.isActive());
			assertNumUsers(0);

			TestTransaction.start();
			// perform other actions against the database that will
			// be automatically rolled back after the test completes...
		}

		protected void assertNumUsers(int expected) {
			assertEquals("Number of rows in the [user] table.", expected, countRowsInTable("user"));
		}
	}
----

[[testcontext-tx-before-and-after-tx]]
===== Executing code outside of a transaction

Occasionally you need to execute certain code before or after a transactional test method
but outside the transactional context -- for example, to verify the initial database state
prior to execution of your test or to verify expected transactional commit behavior after
test execution (if the test was configured to commit the transaction).
`TransactionalTestExecutionListener` supports the `@BeforeTransaction` and
`@AfterTransaction` annotations exactly for such scenarios. Simply annotate any `void`
method in a test class or any `void` default method in a test interface with one of these
annotations, and the `TransactionalTestExecutionListener` ensures that your __before
transaction method__ or __after transaction method__ is executed at the appropriate time.

[TIP]
====
Any __before methods__ (such as methods annotated with JUnit 4's `@Before`) and any __after
methods__ (such as methods annotated with JUnit 4's `@After`) are executed __within__ a
transaction. In addition, methods annotated with `@BeforeTransaction` or
`@AfterTransaction` are naturally not executed for test methods that are not configured
to run within a transaction.
====

[[testcontext-tx-mgr-config]]
===== Configuring a transaction manager

`TransactionalTestExecutionListener` expects a `PlatformTransactionManager` bean to be
defined in the Spring `ApplicationContext` for the test. In case there are multiple
instances of `PlatformTransactionManager` within the test's `ApplicationContext`, a
_qualifier_ may be declared via `@Transactional("myTxMgr")` or
`@Transactional(transactionManager = "myTxMgr")`, or `TransactionManagementConfigurer`
can be implemented by an `@Configuration` class. Consult the javadocs for
`TestContextTransactionUtils.retrieveTransactionManager()` for details on the algorithm
used to look up a transaction manager in the test's `ApplicationContext`.

[[testcontext-tx-annotation-demo]]
===== Demonstration of all transaction-related annotations

The following JUnit 4 based example displays a fictitious integration testing scenario
highlighting all transaction-related annotations. The example is **not** intended to
demonstrate best practices but rather to demonstrate how these annotations can be used.
Consult the <<integration-testing-annotations,annotation support>> section for further
information and configuration examples. <<testcontext-executing-sql-declaratively-tx,
Transaction management for `@Sql`>> contains an additional example using `@Sql` for
declarative SQL script execution with default transaction rollback semantics.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@RunWith(SpringRunner.class)
	@ContextConfiguration
	**@Transactional(transactionManager = "txMgr")**
	**@Commit**
	public class FictitiousTransactionalTest {

		**@BeforeTransaction**
		void verifyInitialDatabaseState() {
			// logic to verify the initial state before a transaction is started
		}

		@Before
		public void setUpTestDataWithinTransaction() {
			// set up test data within the transaction
		}

		@Test
		// overrides the class-level @Commit setting
		**@Rollback**
		public void modifyDatabaseWithinTransaction() {
			// logic which uses the test data and modifies database state
		}

		@After
		public void tearDownWithinTransaction() {
			// execute "tear down" logic within the transaction
		}

		**@AfterTransaction**
		void verifyFinalDatabaseState() {
			// logic to verify the final state after transaction has rolled back
		}

	}
----

[[testcontext-tx-false-positives]]
.Avoid false positives when testing ORM code
[NOTE]
====
When you test application code that manipulates the state of a Hibernate session or JPA
persistence context, make sure to __flush__ the underlying unit of work within test
methods that execute that code. Failing to flush the underlying unit of work can produce
__false positives__: your test may pass, but the same code throws an exception in a live,
production environment. In the following Hibernate-based example test case, one method
demonstrates a false positive, and the other method correctly exposes the results of
flushing the session. Note that this applies to any ORM frameworks that maintain an
in-memory __unit of work__.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	// ...

	@Autowired
	SessionFactory sessionFactory;

	@Transactional
	@Test // no expected exception!
	public void falsePositive() {
		updateEntityInHibernateSession();
		// False positive: an exception will be thrown once the Hibernate
		// Session is finally flushed (i.e., in production code)
	}

	@Transactional
	@Test(expected = ...)
	public void updateWithSessionFlush() {
		updateEntityInHibernateSession();
		// Manual flush is required to avoid false positive in test
		sessionFactory.getCurrentSession().flush();
	}

	// ...
----

Or for JPA:

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	// ...

	@PersistenceContext
	EntityManager entityManager;

	@Transactional
	@Test // no expected exception!
	public void falsePositive() {
		updateEntityInJpaPersistenceContext();
		// False positive: an exception will be thrown once the JPA
		// EntityManager is finally flushed (i.e., in production code)
	}

	@Transactional
	@Test(expected = ...)
	public void updateWithEntityManagerFlush() {
		updateEntityInJpaPersistenceContext();
		// Manual flush is required to avoid false positive in test
		entityManager.flush();
	}

	// ...
----
====


[[testcontext-executing-sql]]
==== Executing SQL scripts

When writing integration tests against a relational database, it is often beneficial
to execute SQL scripts to modify the database schema or insert test data into tables.
The `spring-jdbc` module provides support for _initializing_ an embedded or existing
database by executing SQL scripts when the Spring `ApplicationContext` is loaded. See
<<jdbc-embedded-database-support>> and <<jdbc-embedded-database-dao-testing>> for
details.

Although it is very useful to initialize a database for testing _once_ when the
`ApplicationContext` is loaded, sometimes it is essential to be able to modify the
database _during_ integration tests. The following sections explain how to execute SQL
scripts programmatically and declaratively during integration tests.

[[testcontext-executing-sql-programmatically]]
===== Executing SQL scripts programmatically

Spring provides the following options for executing SQL scripts programmatically within
integration test methods.

* `org.springframework.jdbc.datasource.init.ScriptUtils`
* `org.springframework.jdbc.datasource.init.ResourceDatabasePopulator`
* `org.springframework.test.context.junit4.AbstractTransactionalJUnit4SpringContextTests`
* `org.springframework.test.context.testng.AbstractTransactionalTestNGSpringContextTests`

`ScriptUtils` provides a collection of static utility methods for working with SQL scripts
and is mainly intended for internal use within the framework. However, if you require
full control over how SQL scripts are parsed and executed, `ScriptUtils` may suit your
needs better than some of the other alternatives described below. Consult the javadocs for
individual methods in `ScriptUtils` for further details.

`ResourceDatabasePopulator` provides a simple object-based API for programmatically
populating, initializing, or cleaning up a database using SQL scripts defined in
external resources. `ResourceDatabasePopulator` provides options for configuring the
character encoding, statement separator, comment delimiters, and error handling flags
used when parsing and executing the scripts, and each of the configuration options has
a reasonable default value. Consult the javadocs for details on default values. To
execute the scripts configured in a `ResourceDatabasePopulator`, you can invoke either
the `populate(Connection)` method to execute the populator against a
`java.sql.Connection` or the `execute(DataSource)` method to execute the populator
against a `javax.sql.DataSource`. The following example specifies SQL scripts for a test
schema and test data, sets the statement separator to `"@@"`, and then executes the
scripts against a `DataSource`.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@Test
	public void databaseTest {
		ResourceDatabasePopulator populator = new ResourceDatabasePopulator();
		populator.addScripts(
				new ClassPathResource("test-schema.sql"),
				new ClassPathResource("test-data.sql"));
		populator.setSeparator("@@");
		populator.execute(this.dataSource);
		// execute code that uses the test schema and data
	}
----

Note that `ResourceDatabasePopulator` internally delegates to `ScriptUtils` for parsing
and executing SQL scripts. Similarly, the `executeSqlScript(..)` methods in
<<testcontext-support-classes-junit4, `AbstractTransactionalJUnit4SpringContextTests`>> and
<<testcontext-support-classes-testng, `AbstractTransactionalTestNGSpringContextTests`>>
internally use a `ResourceDatabasePopulator` for executing SQL scripts. Consult the javadocs
for the various `executeSqlScript(..)` methods for further details.

[[testcontext-executing-sql-declaratively]]
===== Executing SQL scripts declaratively with @Sql

In addition to the aforementioned mechanisms for executing SQL scripts
_programmatically_, SQL scripts can also be configured _declaratively_ in the Spring
TestContext Framework. Specifically, the `@Sql` annotation can be declared on a test
class or test method to configure the resource paths to SQL scripts that should be
executed against a given database either before or after an integration test method. Note
that method-level declarations override class-level declarations and that support for
`@Sql` is provided by the `SqlScriptsTestExecutionListener` which is enabled by default.

*Path resource semantics*

Each path will be interpreted as a Spring `Resource`. A plain path -- for example,
`"schema.sql"` -- will be treated as a classpath resource that is _relative_ to the
package in which the test class is defined. A path starting with a slash will be treated
as an _absolute_ classpath resource, for example: `"/org/example/schema.sql"`. A path
which references a URL (e.g., a path prefixed with `classpath:`, `file:`, `http:`, etc.)
will be loaded using the specified resource protocol.

The following example demonstrates how to use `@Sql` at the class level and at the method
level within a JUnit 4 based integration test class.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@RunWith(SpringRunner.class)
	@ContextConfiguration
	@Sql("/test-schema.sql")
	public class DatabaseTests {

		@Test
		public void emptySchemaTest {
			// execute code that uses the test schema without any test data
		}

		@Test
		@Sql({"/test-schema.sql", "/test-user-data.sql"})
		public void userTest {
			// execute code that uses the test schema and test data
		}
	}
----

*Default script detection*

If no SQL scripts are specified, an attempt will be made to detect a `default` script
depending on where `@Sql` is declared. If a default cannot be detected, an
`IllegalStateException` will be thrown.

* __class-level declaration__: if the annotated test class is `com.example.MyTest`, the
	corresponding default script is `"classpath:com/example/MyTest.sql"`.
* __method-level declaration__: if the annotated test method is named `testMethod()` and is
	defined in the class `com.example.MyTest`, the corresponding default script is
	`"classpath:com/example/MyTest.testMethod.sql"`.

*Declaring multiple `@Sql` sets*

If multiple sets of SQL scripts need to be configured for a given test class or test
method but with different syntax configuration, different error handling rules, or
different execution phases per set, it is possible to declare multiple instances of
`@Sql`. With Java 8, `@Sql` can be used as a _repeatable_ annotation. Otherwise, the
`@SqlGroup` annotation can be used as an explicit container for declaring multiple
instances of `@Sql`.

The following example demonstrates the use of `@Sql` as a repeatable annotation using
Java 8. In this scenario the `test-schema.sql` script uses a different syntax for
single-line comments.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@Test
	@Sql(scripts = "/test-schema.sql", config = @SqlConfig(commentPrefix = "`"))
	@Sql("/test-user-data.sql")
	public void userTest {
		// execute code that uses the test schema and test data
	}
----

The following example is identical to the above except that the `@Sql` declarations are
grouped together within `@SqlGroup` for compatibility with Java 6 and Java 7.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@Test
	@SqlGroup({
		@Sql(scripts = "/test-schema.sql", config = @SqlConfig(commentPrefix = "`")),
		@Sql("/test-user-data.sql")
	)}
	public void userTest {
		// execute code that uses the test schema and test data
	}
----

*Script execution phases*

By default, SQL scripts will be executed _before_ the corresponding test method. However,
if a particular set of scripts needs to be executed _after_ the test method -- for
example, to clean up database state -- the `executionPhase` attribute in `@Sql` can be
used as seen in the following example. Note that `ISOLATED` and `AFTER_TEST_METHOD` are
statically imported from `Sql.TransactionMode` and `Sql.ExecutionPhase` respectively.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@Test
	@Sql(
		scripts = "create-test-data.sql",
		config = @SqlConfig(transactionMode = ISOLATED)
	)
	@Sql(
		scripts = "delete-test-data.sql",
		config = @SqlConfig(transactionMode = ISOLATED),
		executionPhase = AFTER_TEST_METHOD
	)
	public void userTest {
		// execute code that needs the test data to be committed
		// to the database outside of the test's transaction
	}
----

*Script configuration with `@SqlConfig`*

Configuration for script parsing and error handling can be configured via the
`@SqlConfig` annotation. When declared as a class-level annotation on an integration test
class, `@SqlConfig` serves as _global_ configuration for all SQL scripts within the test
class hierarchy. When declared directly via the `config` attribute of the `@Sql`
annotation, `@SqlConfig` serves as _local_ configuration for the SQL scripts declared
within the enclosing `@Sql` annotation. Every attribute in `@SqlConfig` has an implicit
default value which is documented in the javadocs of the corresponding attribute. Due to
the rules defined for annotation attributes in the Java Language Specification, it is
unfortunately not possible to assign a value of `null` to an annotation attribute. Thus,
in order to support overrides of inherited global configuration, `@SqlConfig` attributes
have an explicit default value of either `""` for Strings or `DEFAULT` for Enums. This
approach allows local declarations of `@SqlConfig` to selectively override individual
attributes from global declarations of `@SqlConfig` by providing a value other than `""`
or `DEFAULT`. Global `@SqlConfig` attributes are inherited whenever local `@SqlConfig`
attributes do not supply an explicit value other than `""` or `DEFAULT`. Explicit _local_
configuration therefore overrides _global_ configuration.

The configuration options provided by `@Sql` and `@SqlConfig` are equivalent to those
supported by `ScriptUtils` and `ResourceDatabasePopulator` but are a superset of those
provided by the `<jdbc:initialize-database/>` XML namespace element. Consult the javadocs
of individual attributes in `@Sql` and `@SqlConfig` for details.

[[testcontext-executing-sql-declaratively-tx]]
*Transaction management for `@Sql`*

By default, the `SqlScriptsTestExecutionListener` will infer the desired transaction
semantics for scripts configured via `@Sql`. Specifically, SQL scripts will be executed
without a transaction, within an existing Spring-managed transaction -- for example, a
transaction managed by the `TransactionalTestExecutionListener` for a test annotated with
`@Transactional` -- or within an isolated transaction, depending on the configured value
of the `transactionMode` attribute in `@SqlConfig` and the presence of a
`PlatformTransactionManager` in the test's `ApplicationContext`. As a bare minimum
however, a `javax.sql.DataSource` must be present in the test's `ApplicationContext`.

If the algorithms used by `SqlScriptsTestExecutionListener` to detect a `DataSource` and
`PlatformTransactionManager` and infer the transaction semantics do not suit your needs,
you may specify explicit names via the `dataSource` and `transactionManager` attributes
of `@SqlConfig`. Furthermore, the transaction propagation behavior can be controlled via
the `transactionMode` attribute of `@SqlConfig` -- for example, if scripts should be
executed in an isolated transaction. Although a thorough discussion of all supported
options for transaction management with `@Sql` is beyond the scope of this reference
manual, the javadocs for `@SqlConfig` and `SqlScriptsTestExecutionListener` provide
detailed information, and the following example demonstrates a typical testing scenario
using JUnit 4 and transactional tests with `@Sql`. Note that there is no need to clean up
the database after the `usersTest()` method is executed since any changes made to the
database (either within the test method or within the `/test-data.sql` script) will
be automatically rolled back by the `TransactionalTestExecutionListener` (see
<<testcontext-tx,transaction management>> for details).

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@RunWith(SpringRunner.class)
	@ContextConfiguration(classes = TestDatabaseConfig.class)
	@Transactional
	public class TransactionalSqlScriptsTests {

		protected JdbcTemplate jdbcTemplate;

		@Autowired
		public void setDataSource(DataSource dataSource) {
			this.jdbcTemplate = new JdbcTemplate(dataSource);
		}

		@Test
		@Sql("/test-data.sql")
		public void usersTest() {
			// verify state in test database:
			assertNumUsers(2);
			// execute code that uses the test data...
		}

		protected int countRowsInTable(String tableName) {
			return JdbcTestUtils.countRowsInTable(this.jdbcTemplate, tableName);
		}

		protected void assertNumUsers(int expected) {
			assertEquals("Number of rows in the [user] table.", expected, countRowsInTable("user"));
		}
	}
----


[[testcontext-support-classes]]
==== TestContext Framework support classes

[[testcontext-junit4-runner]]
===== Spring JUnit 4 Runner

The __Spring TestContext Framework__ offers full integration with JUnit 4 through a
custom runner (supported on JUnit 4.12 or higher). By annotating test classes with
`@RunWith(SpringJUnit4ClassRunner.class)` or the shorter `@RunWith(SpringRunner.class)`
variant, developers can implement standard JUnit 4 based unit and integration tests and
simultaneously reap the benefits of the TestContext framework such as support for loading
application contexts, dependency injection of test instances, transactional test method
execution, and so on. If you would like to use the Spring TestContext Framework with an
alternative runner such as JUnit 4's `Parameterized` or third-party runners such as the
`MockitoJUnitRunner`, you may optionally use <<testcontext-junit4-rules,Spring's support
for JUnit rules>> instead.

The following code listing displays the minimal requirements for configuring a test class
to run with the custom Spring `Runner`. `@TestExecutionListeners` is configured with an
empty list in order to disable the default listeners, which otherwise would require an
`ApplicationContext` to be configured through `@ContextConfiguration`.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@RunWith(SpringRunner.class)
	@TestExecutionListeners({})
	public class SimpleTest {

		@Test
		public void testMethod() {
			// execute test logic...
		}
	}
----

[[testcontext-junit4-rules]]
===== Spring JUnit 4 Rules

The `org.springframework.test.context.junit4.rules` package provides the following JUnit
4 rules (supported on JUnit 4.12 or higher).

* `SpringClassRule`
* `SpringMethodRule`

`SpringClassRule` is a JUnit `TestRule` that supports _class-level_ features of the
_Spring TestContext Framework_; whereas, `SpringMethodRule` is a JUnit `MethodRule` that
supports instance-level and method-level features of the _Spring TestContext Framework_.

In contrast to the `SpringRunner`, Spring's rule-based JUnit support has the advantage
that it is independent of any `org.junit.runner.Runner` implementation and can therefore
be combined with existing alternative runners like JUnit 4's `Parameterized` or third-party
runners such as the `MockitoJUnitRunner`.

In order to support the full functionality of the TestContext framework, a
`SpringClassRule` must be combined with a `SpringMethodRule`. The following example
demonstrates the proper way to declare these rules in an integration test.


[source,java,indent=0]
[subs="verbatim,quotes"]
----
	// Optionally specify a non-Spring Runner via @RunWith(...)
	@ContextConfiguration
	public class IntegrationTest {

		@ClassRule
		public static final SpringClassRule springClassRule = new SpringClassRule();

		@Rule
		public final SpringMethodRule springMethodRule = new SpringMethodRule();

		@Test
		public void testMethod() {
			// execute test logic...
		}
	}
----

[[testcontext-support-classes-junit4]]
===== JUnit 4 support classes

The `org.springframework.test.context.junit4` package provides the following support
classes for JUnit 4 based test cases (supported on JUnit 4.12 or higher).

* `AbstractJUnit4SpringContextTests`
* `AbstractTransactionalJUnit4SpringContextTests`

`AbstractJUnit4SpringContextTests` is an abstract base test class that integrates the
__Spring TestContext Framework__ with explicit `ApplicationContext` testing support in
a JUnit 4 environment. When you extend `AbstractJUnit4SpringContextTests`, you can
access a `protected` `applicationContext` instance variable that can be used to perform
explicit bean lookups or to test the state of the context as a whole.

`AbstractTransactionalJUnit4SpringContextTests` is an abstract __transactional__ extension
of `AbstractJUnit4SpringContextTests` that adds some convenience functionality for JDBC
access. This class expects a `javax.sql.DataSource` bean and a `PlatformTransactionManager`
bean to be defined in the `ApplicationContext`. When you extend
`AbstractTransactionalJUnit4SpringContextTests` you can access a `protected` `jdbcTemplate`
instance variable that can be used to execute SQL statements to query the database. Such
queries can be used to confirm database state both __prior to__ and __after__ execution of
database-related application code, and Spring ensures that such queries run in the scope of
the same transaction as the application code. When used in conjunction with an ORM tool,
be sure to avoid <<testcontext-tx-false-positives,false positives>>. As mentioned in
<<integration-testing-support-jdbc>>, `AbstractTransactionalJUnit4SpringContextTests`
also provides convenience methods which delegate to methods in `JdbcTestUtils` using the
aforementioned `jdbcTemplate`. Furthermore, `AbstractTransactionalJUnit4SpringContextTests`
provides an `executeSqlScript(..)` method for executing SQL scripts against the configured
`DataSource`.

[TIP]
====
These classes are a convenience for extension. If you do not want your test classes to be
tied to a Spring-specific class hierarchy, you can configure your own custom test classes
by using `@RunWith(SpringRunner.class)` or <<testcontext-junit4-rules,Spring's
JUnit rules>>.
====


[[testcontext-junit-jupiter-extension]]
===== JUnit 5 Support

Spring Framework 5.0 offers full integration with the _JUnit Jupiter_ testing framework
introduced in JUnit 5. Developers are therefore encouraged to upgrade to Spring 5.x to
benefit fully from Spring's support for JUnit 5. However, if your project for some reason
cannot yet upgrade to Spring 5.x, you may be interested in using the
https://github.com/sbrannen/spring-test-junit5[spring-test-junit5] project as a temporary
solution to assist you in upgrading to JUnit 5 while still using Spring Framework 4.3.x.


[[testcontext-support-classes-testng]]
===== TestNG support classes

The `org.springframework.test.context.testng` package provides the following support
classes for TestNG based test cases.

* `AbstractTestNGSpringContextTests`
* `AbstractTransactionalTestNGSpringContextTests`

`AbstractTestNGSpringContextTests` is an abstract base test class that integrates the
__Spring TestContext Framework__ with explicit `ApplicationContext` testing support in
a TestNG environment. When you extend `AbstractTestNGSpringContextTests`, you can
access a `protected` `applicationContext` instance variable that can be used to perform
explicit bean lookups or to test the state of the context as a whole.

`AbstractTransactionalTestNGSpringContextTests` is an abstract __transactional__ extension
of `AbstractTestNGSpringContextTests` that adds some convenience functionality for JDBC
access. This class expects a `javax.sql.DataSource` bean and a `PlatformTransactionManager`
bean to be defined in the `ApplicationContext`. When you extend
`AbstractTransactionalTestNGSpringContextTests` you can access a `protected` `jdbcTemplate`
instance variable that can be used to execute SQL statements to query the database. Such
queries can be used to confirm database state both __prior to__ and __after__ execution of
database-related application code, and Spring ensures that such queries run in the scope of
the same transaction as the application code. When used in conjunction with an ORM tool,
be sure to avoid <<testcontext-tx-false-positives,false positives>>. As mentioned in
<<integration-testing-support-jdbc>>, `AbstractTransactionalTestNGSpringContextTests`
also provides convenience methods which delegate to methods in `JdbcTestUtils` using the
aforementioned `jdbcTemplate`. Furthermore, `AbstractTransactionalTestNGSpringContextTests`
provides an `executeSqlScript(..)` method for executing SQL scripts against the configured
`DataSource`.


[TIP]
====
These classes are a convenience for extension. If you do not want your test classes to be
tied to a Spring-specific class hierarchy, you can configure your own custom test classes
by using `@ContextConfiguration`, `@TestExecutionListeners`, and so on, and by manually
instrumenting your test class with a `TestContextManager`. See the source code of
`AbstractTestNGSpringContextTests` for an example of how to instrument your test class.
====



[[spring-mvc-test-framework]]
=== Spring MVC Test Framework

The __Spring MVC Test framework__ provides first class support for testing Spring MVC
code using a fluent API that can be used with JUnit, TestNG, or any other testing
framework. It's built on the
{api-spring-framework}/mock/web/package-summary.html[Servlet API mock objects]
from the `spring-test` module and hence does _not_ use a running Servlet container. It
uses the `DispatcherServlet` to provide full Spring MVC runtime behavior and provides support
for loading actual Spring configuration with the __TestContext framework__ in addition to a
standalone mode in which controllers may be instantiated manually and tested one at a time.

__Spring MVC Test__ also provides client-side support for testing code that uses
the `RestTemplate`. Client-side tests mock the server responses and also do _not_
use a running server.

[TIP]
====
Spring Boot provides an option to write full, end-to-end integration tests that include
a running server. If this is your goal please have a look at the
{doc-spring-boot}/html/boot-features-testing.html#boot-features-testing-spring-boot-applications[Spring Boot reference page].
For more information on the differences between out-of-container and end-to-end
integration tests, see <<spring-mvc-test-vs-end-to-end-integration-tests>>.
====


[[spring-mvc-test-server]]
==== Server-Side Tests

It's easy to write a plain unit test for a Spring MVC controller using JUnit or TestNG:
simply instantiate the controller, inject it with mocked or stubbed dependencies, and call
its methods passing `MockHttpServletRequest`, `MockHttpServletResponse`, etc., as necessary.
However, when writing such a unit test, much remains untested: for example, request
mappings, data binding, type conversion, validation, and much more. Furthermore, other
controller methods such as `@InitBinder`, `@ModelAttribute`, and `@ExceptionHandler` may
also be invoked as part of the request processing lifecycle.

The goal of __Spring MVC Test__ is to provide an effective way for testing controllers
by performing requests and generating responses through the actual `DispatcherServlet`.

__Spring MVC Test__ builds on the familiar <<mock-objects-servlet,"mock" implementations
of the Servlet API>> available in the `spring-test` module. This allows performing
requests and generating responses without the need for running in a Servlet container.
For the most part everything should work as it does at runtime with a few notable
exceptions as explained in <<spring-mvc-test-vs-end-to-end-integration-tests>>. Here is a
JUnit 4 based example of using Spring MVC Test:

[source,java,indent=0]
----
	import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.*;
	import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.*;

	@RunWith(SpringRunner.class)
	@WebAppConfiguration
	@ContextConfiguration("test-servlet-context.xml")
	public class ExampleTests {

		@Autowired
		private WebApplicationContext wac;

		private MockMvc mockMvc;

		@Before
		public void setup() {
			this.mockMvc = MockMvcBuilders.webAppContextSetup(this.wac).build();
		}

		@Test
		public void getAccount() throws Exception {
			this.mockMvc.perform(get("/accounts/1").accept(MediaType.parseMediaType("application/json;charset=UTF-8")))
				.andExpect(status().isOk())
				.andExpect(content().contentType("application/json"))
				.andExpect(jsonPath("$.name").value("Lee"));
		}
	}
----

The above test relies on the `WebApplicationContext` support of the __TestContext framework__
for loading Spring configuration from an XML configuration file located in the same package
as the test class, but Java-based and Groovy-based configuration are also supported. See these
https://github.com/spring-projects/spring-framework/tree/master/spring-test/src/test/java/org/springframework/test/web/servlet/samples/context[sample tests].

The `MockMvc` instance is used to perform a `GET` request to `"/accounts/1"` and verify
that the resulting response has status 200, the content type is `"application/json"`, and the
response body has a JSON property called "name" with the value "Lee". The `jsonPath`
syntax is supported through the Jayway https://github.com/jayway/JsonPath[JsonPath
project]. There are lots of other options for verifying the result of the performed
request that will be discussed below.

[[spring-mvc-test-server-static-imports]]
===== Static Imports

The fluent API in the example above requires a few static imports such as
`MockMvcRequestBuilders.{asterisk}`, `MockMvcResultMatchers.{asterisk}`, 
and `MockMvcBuilders.{asterisk}`. An easy way to find these classes is to search for
types matching __"MockMvc*"__. If using Eclipse, be sure to add them as 
"favorite static members" in the Eclipse preferences under 
__Java -> Editor -> Content Assist -> Favorites__. That will allow use of content
assist after typing the first character of the static method name. Other IDEs (e.g.
IntelliJ) may not require any additional configuration. Just check the support for code
completion on static members.

[[spring-mvc-test-server-setup-options]]
===== Setup Choices

There are two main options for creating an instance of `MockMvc`.
The first is to load Spring MVC configuration through the __TestContext
framework__, which loads the Spring configuration and injects a `WebApplicationContext`
into the test to use to build a `MockMvc` instance:

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@RunWith(SpringRunner.class)
	@WebAppConfiguration
	@ContextConfiguration("my-servlet-context.xml")
	public class MyWebTests {

		@Autowired
		private WebApplicationContext wac;

		private MockMvc mockMvc;

		@Before
		public void setup() {
			this.mockMvc = MockMvcBuilders.webAppContextSetup(this.wac).build();
		}

		// ...

	}
----

The second is to simply create a controller instance manually without loading Spring
configuration. Instead basic default configuration, roughly comparable to that of
the MVC JavaConfig or the MVC namespace, is automatically created and can be customized
to a degree:

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	public class MyWebTests {

		private MockMvc mockMvc;

		@Before
		public void setup() {
			this.mockMvc = MockMvcBuilders.standaloneSetup(new AccountController()).build();
		}

		// ...

	}
----

Which setup option should you use?

The __"webAppContextSetup"__ loads your actual Spring MVC configuration resulting in a
more complete integration test. Since the __TestContext framework__ caches the loaded
Spring configuration, it helps keep tests running fast, even as you introduce more tests
in your test suite. Furthermore, you can inject mock services into controllers through
Spring configuration in order to remain focused on testing the web layer. Here is an
example of declaring a mock service with Mockito:

[source,xml,indent=0]
[subs="verbatim,quotes"]
----
	<bean id="accountService" class="org.mockito.Mockito" factory-method="mock">
		<constructor-arg value="org.example.AccountService"/>
	</bean>
----

You can then inject the mock service into the test in order set up and verify
expectations:

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	@RunWith(SpringRunner.class)
	@WebAppConfiguration
	@ContextConfiguration("test-servlet-context.xml")
	public class AccountTests {

		@Autowired
		private WebApplicationContext wac;

		private MockMvc mockMvc;

		@Autowired
		private AccountService accountService;

		// ...

	}
----

The __"standaloneSetup"__ on the other hand is a little closer to a unit test. It tests
one controller at a time: the controller can be injected with mock dependencies manually,
and it doesn't involve loading Spring configuration. Such tests are more focused on style
and make it easier to see which controller is being tested, whether any specific Spring
MVC configuration is required to work, and so on. The "standaloneSetup" is also a very
convenient way to write ad-hoc tests to verify specific behavior or to debug an issue.

Just like with any "integration vs. unit testing" debate, there is no right or wrong
answer. However, using the "standaloneSetup" does imply the need for additional
"webAppContextSetup" tests in order to verify your Spring MVC configuration.
Alternatively, you may choose to write all tests with "webAppContextSetup" in order to
always test against your actual Spring MVC configuration.

[[spring-mvc-test-server-performing-requests]]
===== Performing Requests

It's easy to perform requests using any HTTP method:

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	mockMvc.perform(post("/hotels/{id}", 42).accept(MediaType.APPLICATION_JSON));
----

You can also perform file upload requests that internally use
`MockMultipartHttpServletRequest` so that there is no actual parsing of a multipart
request but rather you have to set it up:

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	mockMvc.perform(fileUpload("/doc").file("a1", "ABC".getBytes("UTF-8")));
----

You can specify query parameters in URI template style:

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	mockMvc.perform(get("/hotels?foo={foo}", "bar"));
----

Or you can add Servlet request parameters representing either query of form parameters:

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	mockMvc.perform(get("/hotels").param("foo", "bar"));
----

If application code relies on Servlet request parameters and doesn't check the query
string explicitly (as is most often the case) then it doesn't matter which option you use.
Keep in mind however that query params provided with the URI template will be decoded while
request parameters provided through the `param(...)` method are expected to already be decoded.

In most cases it's preferable to leave out the context path and the Servlet path from
the request URI. If you must test with the full request URI, be sure to set the
`contextPath` and `servletPath` accordingly so that request mappings will work:

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	mockMvc.perform(get("/app/main/hotels/{id}").contextPath("/app").servletPath("/main"))
----

Looking at the above example, it would be cumbersome to set the contextPath and
servletPath with every performed request. Instead you can set up default request
properties:

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	public class MyWebTests {

		private MockMvc mockMvc;

		@Before
		public void setup() {
			mockMvc = standaloneSetup(new AccountController())
				.defaultRequest(get("/")
				.contextPath("/app").servletPath("/main")
				.accept(MediaType.APPLICATION_JSON).build();
		}
----

The above properties will affect every request performed through the `MockMvc` instance.
If the same property is also specified on a given request, it overrides the default value.
That is why the HTTP method and URI in the default request don't matter since they must be
specified on every request.

[[spring-mvc-test-server-defining-expectations]]
===== Defining Expectations

Expectations can be defined by appending one or more `.andExpect(..)` calls after
performing a request:

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	mockMvc.perform(get("/accounts/1")).andExpect(status().isOk());
----

`MockMvcResultMatchers.*` provides a number of expectations, some of which are further
nested with more detailed expectations.

Expectations fall in two general categories. The first category of assertions verifies
properties of the response: for example, the response status, headers, and content. These
are the most important results to assert.

The second category of assertions goes beyond the response. These assertions allow
one to inspect Spring MVC specific aspects such as which controller method processed
the request, whether an exception was raised and handled, what the content of the model
is, what view was selected, what flash attributes were added, and so on. They also allow
one to inspect Servlet specific aspects such as request and session attributes.

The following test asserts that binding or validation failed:

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	mockMvc.perform(post("/persons"))
		.andExpect(status().isOk())
		.andExpect(model().attributeHasErrors("person"));
----

Many times when writing tests, it's useful to _dump_ the results of the performed request.
This can be done as follows, where `print()` is a static import from
`MockMvcResultHandlers`:

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	mockMvc.perform(post("/persons"))
		.andDo(print())
		.andExpect(status().isOk())
		.andExpect(model().attributeHasErrors("person"));
----

As long as request processing does not cause an unhandled exception, the `print()` method
will print all the available result data to `System.out`. Spring Framework 4.2 introduced
a `log()` method and two additional variants of the `print()` method, one that accepts
an `OutputStream` and one that accepts a `Writer`. For example, invoking
`print(System.err)` will print the result data to `System.err`; while invoking
`print(myWriter)` will print the result data to a custom writer. If you would like to
have the result data _logged_ instead of printed, simply invoke the `log()` method which
will log the result data as a single `DEBUG` message under the
`org.springframework.test.web.servlet.result` logging category.

In some cases, you may want to get direct access to the result and verify something that
cannot be verified otherwise. This can be achieved by appending `.andReturn()` after all
other expectations:

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	MvcResult mvcResult = mockMvc.perform(post("/persons")).andExpect(status().isOk()).andReturn();
	// ...
----

If all tests repeat the same expectations you can set up common expectations once
when building the `MockMvc` instance:

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	standaloneSetup(new SimpleController())
		.alwaysExpect(status().isOk())
		.alwaysExpect(content().contentType("application/json;charset=UTF-8"))
		.build()
----

Note that common expectations are __always__ applied and cannot be overridden without
creating a separate `MockMvc` instance.

When JSON response content contains hypermedia links created with
https://github.com/spring-projects/spring-hateoas[Spring HATEOAS], the resulting links can
be verified using JsonPath expressions:

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	mockMvc.perform(get("/people").accept(MediaType.APPLICATION_JSON))
		.andExpect(jsonPath("$.links[?(@.rel == 'self')].href").value("http://localhost:8080/people"));
----

When XML response content contains hypermedia links created with
https://github.com/spring-projects/spring-hateoas[Spring HATEOAS], the resulting links can
be verified using XPath expressions:

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	Map<String, String> ns = Collections.singletonMap("ns", "http://www.w3.org/2005/Atom");
	mockMvc.perform(get("/handle").accept(MediaType.APPLICATION_XML))
		.andExpect(xpath("/person/ns:link[@rel='self']/@href", ns).string("http://localhost:8080/people"));
----

[[spring-mvc-test-server-filters]]
===== Filter Registrations

When setting up a `MockMvc` instance, you can register one or more Servlet `Filter` instances:

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	mockMvc = standaloneSetup(new PersonController()).addFilters(new CharacterEncodingFilter()).build();
----

Registered filters will be invoked through via the `MockFilterChain` from `spring-test`, and the
last filter will delegate to the `DispatcherServlet`.

[[spring-mvc-test-vs-end-to-end-integration-tests]]
===== Differences between Out-of-Container and End-to-End Integration Tests

As mentioned earlier __Spring MVC Test__ is built on the Servlet API mock objects from
the `spring-test` module and does not use a running Servlet container. Therefore
there are some important differences compared to full end-to-end integration tests
with an actual client and server running.

The easiest way to think about this is starting with a blank `MockHttpServletRequest`.
Whatever you add to it is what the request will be. Things that may catch you by surprise
are that there is no context path by default, no `jsessionid` cookie, no forwarding, error,
or async dispatches, and therefore no actual JSP rendering. Instead, "forwarded" and
"redirected" URLs are saved in the `MockHttpServletResponse` and can be asserted with
expectations.

This means if you are using JSPs you can verify the JSP page to which the request was
forwarded, but there won't be any HTML rendered. In other words, the JSP will not be
_invoked_. Note however that all other rendering technologies which don't rely on
forwarding such as Thymeleaf, Freemarker, and Velocity will render HTML to the response
body as expected. The same is true for rendering JSON, XML, and other formats via
`@ResponseBody` methods.

Alternatively you may consider the full end-to-end integration testing support from
Spring Boot via `@WebIntegrationTest`. See the
{doc-spring-boot}/html/boot-features-testing.html#boot-features-testing-spring-boot-applications[Spring Boot reference].

There are pros and cons for each approach. The options provided in __Spring MVC Test__
are different stops on the scale from classic unit testing to full integration testing.
To be certain, none of the options in Spring MVC Test fall under the category of classic
unit testing, but they _are_ a little closer to it. For example, you can isolate the web
layer by injecting mocked services into controllers, in which case you're testing the web
layer only through the `DispatcherServlet` but with actual Spring configuration, just
like you might test the data access layer in isolation from the layers above. Or you
can use the standalone setup focusing on one controller at a time and manually providing
the configuration required to make it work.

Another important distinction when using __Spring MVC Test__ is that conceptually such
tests are on the _inside_ of the server-side so you can check what handler was used,
if an exception was handled with a HandlerExceptionResolver, what the content of the
model is, what binding errors there were, etc. That means it's easier to write
expectations since the server is not a black box as it is when testing it through
an actual HTTP client. This is generally an advantage of classic unit testing, that it's
easier to write, reason about, and debug but does not replace the need for full
integration tests. At the same time it's important not to lose sight of the fact that
the response is the most important thing to check. In short, there is room here for
multiple styles and strategies of testing even within the same project.

[[spring-mvc-test-server-resources]]
===== Further Server-Side Test Examples

The framework's own tests include
https://github.com/spring-projects/spring-framework/tree/master/spring-test/src/test/java/org/springframework/test/web/servlet/samples[many
sample tests] intended to demonstrate how to use Spring MVC Test. Browse these examples
for further ideas. Also the
https://github.com/spring-projects/spring-mvc-showcase[spring-mvc-showcase] has full test
coverage based on Spring MVC Test.


[[spring-mvc-test-server-htmlunit]]
==== HtmlUnit Integration

Spring provides integration between <<spring-mvc-test-server,MockMvc>> and
http://htmlunit.sourceforge.net/[HtmlUnit]. This simplifies performing end-to-end testing
when using HTML based views. This integration enables developers to:

* Easily test HTML pages using tools such as http://htmlunit.sourceforge.net/[HtmlUnit],
https://www.seleniumhq.org[WebDriver], &
http://www.gebish.org/manual/current/testing.html#spock_junit__testng[Geb] without the
need to deploy to a Servlet container
* Test JavaScript within pages
* Optionally test using mock services to speed up testing
* Share logic between in-container end-to-end tests and out-of-container integration tests

[NOTE]
====
`MockMvc` works with templating technologies that do not rely on a Servlet Container (e.g.,
Thymeleaf, Freemarker, Velocity, etc.), but it does not work with JSPs since they rely on
the Servlet Container.
====

[[spring-mvc-test-server-htmlunit-why]]
===== Why HtmlUnit Integration?

The most obvious question that comes to mind is, "Why do I need this?". The answer is best
found by exploring a very basic sample application. Assume you have a Spring MVC web
application that supports CRUD operations on a `Message` object. The application also supports
paging through all messages. How would you go about testing it?

With Spring MVC Test, we can easily test if we are able to create a `Message`.

[source,java,indent=0]
----
	MockHttpServletRequestBuilder createMessage = post("/messages/")
			.param("summary", "Spring Rocks")
			.param("text", "In case you didn't know, Spring Rocks!");

	mockMvc.perform(createMessage)
			.andExpect(status().is3xxRedirection())
			.andExpect(redirectedUrl("/messages/123"));
----

What if we want to test our form view that allows us to create the message? For example,
assume our form looks like the following snippet:

[source,xml,indent=0]
----
	<form id="messageForm" action="/messages/" method="post">
		<div class="pull-right"><a href="/messages/">Messages</a></div>

		<label for="summary">Summary</label>
		<input type="text" class="required" id="summary" name="summary" value="" />

		<label for="text">Message</label>
		<textarea id="text" name="text"></textarea>

		<div class="form-actions">
			<input type="submit" value="Create" />
		</div>
	</form>
----

How do we ensure that our form will produce the correct request to create a new message? A
naive attempt would look like this:

[source,java,indent=0]
----
	mockMvc.perform(get("/messages/form"))
			.andExpect(xpath("//input[@name='summary']").exists())
			.andExpect(xpath("//textarea[@name='text']").exists());
----

This test has some obvious drawbacks. If we update our controller to use the parameter
`message` instead of `text`, our form test would continue to pass even though the HTML
form is out of synch with the controller. To resolve this we can combine our two tests.

[[spring-mvc-test-server-htmlunit-mock-mvc-test]]
[source,java,indent=0]
----
	String summaryParamName = "summary";
	String textParamName = "text";
	mockMvc.perform(get("/messages/form"))
			.andExpect(xpath("//input[@name='" + summaryParamName + "']").exists())
			.andExpect(xpath("//textarea[@name='" + textParamName + "']").exists());

	MockHttpServletRequestBuilder createMessage = post("/messages/")
			.param(summaryParamName, "Spring Rocks")
			.param(textParamName, "In case you didn't know, Spring Rocks!");

	mockMvc.perform(createMessage)
			.andExpect(status().is3xxRedirection())
			.andExpect(redirectedUrl("/messages/123"));
----

This would reduce the risk of our test incorrectly passing, but there are still some
problems.

* What if we have multiple forms on our page? Admittedly we could update our xpath
  expressions, but they get more complicated the more factors we take into account (Are the
  fields the correct type? Are the fields enabled? etc.).
* Another issue is that we are doing double the work we would expect.
  We must first verify the view, and then we submit the view with the same parameters we just
  verified. Ideally this could be done all at once.
* Finally, there are some things that we still cannot account for. For example, what if the
  form has JavaScript validation that we wish to test as well?

The overall problem is that testing a web page does not involve a single interaction.
Instead, it is a combination of how the user interacts with a web page and how that web
page interacts with other resources. For example, the result of a form view is used as
the input to a user for creating a message. In addition, our form view may potentially
utilize additional resources which impact the behavior of the page, such as JavaScript
validation.

[[spring-mvc-test-server-htmlunit-why-integration]]
====== Integration testing to the rescue?

To resolve the issues above we could perform end-to-end integration testing, but this has
some obvious drawbacks. Consider testing the view that allows us to page through the messages.
We might need the following tests.

* Does our page display a notification to the user indicating that no results are available
when the messages are empty?
* Does our page properly display a single message?
* Does our page properly support paging?

To set up these tests, we would need to ensure our database contained the proper messages
in it. This leads to a number of additional challenges.

* Ensuring the proper messages are in the database can be tedious; consider foreign key
  constraints.
* Testing can become slow since each test would need to ensure that the database is in the
  correct state.
* Since our database needs to be in a specific state, we cannot run tests in parallel.
* Performing assertions on things like auto-generated ids, timestamps, etc. can be difficult.

These challenges do not mean that we should abandon end-to-end integration testing
altogether. Instead, we can reduce the number of end-to-end integration tests by
refactoring our detailed tests to use mock services which will execute much faster, more
reliably, and without side effects. We can then implement a small number of _true_
end-to-end integration tests that validate simple workflows to ensure that everything
works together properly.

[[spring-mvc-test-server-htmlunit-why-mockmvc]]
====== Enter HtmlUnit Integration

So how can we achieve a balance between testing the interactions of our pages and still
retain good performance within our test suite? The answer is: "By integrating MockMvc
with HtmlUnit."

[[spring-mvc-test-server-htmlunit-options]]
====== HtmlUnit Integration Options

There are a number of ways to integrate `MockMvc` with HtmlUnit.

* <<spring-mvc-test-server-htmlunit-mah,MockMvc and HtmlUnit>>: Use this option if you
want to use the raw HtmlUnit libraries.
* <<spring-mvc-test-server-htmlunit-webdriver,MockMvc and WebDriver>>: Use this option to
ease development and reuse code between integration and end-to-end testing.
* <<spring-mvc-test-server-htmlunit-geb,MockMvc and Geb>>: Use this option if you would
like to use Groovy for testing, ease development, and reuse code between integration and
end-to-end testing.

[[spring-mvc-test-server-htmlunit-mah]]
===== MockMvc and HtmlUnit

This section describes how to integrate `MockMvc` and HtmlUnit. Use this option if you
want to use the raw HtmlUnit libraries.

[[spring-mvc-test-server-htmlunit-mah-setup]]
====== MockMvc and HtmlUnit Setup

First, make sure that you have included a test dependency on `net.sourceforge.htmlunit:htmlunit`.
In order to use HtmlUnit with Apache HttpComponents 4.5+, you will need to use HtmlUnit
2.18 or higher.

We can easily create an HtmlUnit `WebClient` that integrates with `MockMvc` using the
`MockMvcWebClientBuilder` as follows.

[source,java,indent=0]
----
	@Autowired
	WebApplicationContext context;

	WebClient webClient;

	@Before
	public void setup() {
		webClient = MockMvcWebClientBuilder
				.webAppContextSetup(context)
				.build();
	}
----

[NOTE]
====
This is a simple example of using `MockMvcWebClientBuilder`. For advanced usage see
<<Advanced MockMvcWebClientBuilder>>
====

This will ensure that any URL referencing `localhost` as the server will be directed to
our `MockMvc` instance without the need for a real HTTP connection. Any other URL will be
requested using a network connection as normal. This allows us to easily test the use of
CDNs.

[[spring-mvc-test-server-htmlunit-mah-usage]]
====== MockMvc and HtmlUnit Usage

Now we can use HtmlUnit as we normally would, but without the need to deploy our
application to a Servlet container. For example, we can request the view to create
a message with the following.

[source,java,indent=0]
----
	HtmlPage createMsgFormPage = webClient.getPage("http://localhost/messages/form");
----

[NOTE]
====
The default context path is `""`. Alternatively, we can specify the context path as
illustrated in <<Advanced MockMvcWebClientBuilder>>.
====

Once we have a reference to the `HtmlPage`, we can then fill out the form and submit
it to create a message.

[source,java,indent=0]
----
	HtmlForm form = createMsgFormPage.getHtmlElementById("messageForm");
	HtmlTextInput summaryInput = createMsgFormPage.getHtmlElementById("summary");
	summaryInput.setValueAttribute("Spring Rocks");
	HtmlTextArea textInput = createMsgFormPage.getHtmlElementById("text");
	textInput.setText("In case you didn't know, Spring Rocks!");
	HtmlSubmitInput submit = form.getOneHtmlElementByAttribute("input", "type", "submit");
	HtmlPage newMessagePage = submit.click();
----

Finally, we can verify that a new message was created successfully. The following
assertions use the https://joel-costigliola.github.io/assertj/[AssertJ] library.

[source,java,indent=0]
----
	assertThat(newMessagePage.getUrl().toString()).endsWith("/messages/123");
	String id = newMessagePage.getHtmlElementById("id").getTextContent();
	assertThat(id).isEqualTo("123");
	String summary = newMessagePage.getHtmlElementById("summary").getTextContent();
	assertThat(summary).isEqualTo("Spring Rocks");
	String text = newMessagePage.getHtmlElementById("text").getTextContent();
	assertThat(text).isEqualTo("In case you didn't know, Spring Rocks!");
----

This improves on our <<spring-mvc-test-server-htmlunit-mock-mvc-test,MockMvc test>> in a
number of ways. First we no longer have to explicitly verify our form and then create a
request that looks like the form. Instead, we request the form, fill it out, and submit
it, thereby significantly reducing the overhead.

Another important factor is that http://htmlunit.sourceforge.net/javascript.html[HtmlUnit
uses the Mozilla Rhino engine] to evaluate JavaScript. This means that we can test the
behavior of JavaScript within our pages as well!

Refer to the http://htmlunit.sourceforge.net/gettingStarted.html[HtmlUnit documentation]
for additional information about using HtmlUnit.

[[spring-mvc-test-server-htmlunit-mah-advanced-builder]]
====== Advanced MockMvcWebClientBuilder

In the examples so far, we have used `MockMvcWebClientBuilder` in the simplest way possible,
by building a `WebClient` based on the `WebApplicationContext` loaded for us by the Spring
TestContext Framework. This approach is repeated here.

[source,java,indent=0]
----
	@Autowired
	WebApplicationContext context;

	WebClient webClient;

	@Before
	public void setup() {
		webClient = MockMvcWebClientBuilder
				.webAppContextSetup(context)
				.build();
	}
----

We can also specify additional configuration options.

[source,java,indent=0]
----
	WebClient webClient;

	@Before
	public void setup() {
		webClient = MockMvcWebClientBuilder
				// demonstrates applying a MockMvcConfigurer (Spring Security)
				.webAppContextSetup(context, springSecurity())
				// for illustration only - defaults to ""
				.contextPath("")
				// By default MockMvc is used for localhost only;
				// the following will use MockMvc for example.com and example.org as well
				.useMockMvcForHosts("example.com","example.org")
				.build();
	}
----

As an alternative, we can perform the exact same setup by configuring the `MockMvc`
instance separately and supplying it to the `MockMvcWebClientBuilder` as follows.

[source,java,indent=0]
----
	MockMvc mockMvc = MockMvcBuilders
			.webAppContextSetup(context)
			.apply(springSecurity())
			.build();

	webClient = MockMvcWebClientBuilder
			.mockMvcSetup(mockMvc)
			// for illustration only - defaults to ""
			.contextPath("")
			// By default MockMvc is used for localhost only;
			// the following will use MockMvc for example.com and example.org as well
			.useMockMvcForHosts("example.com","example.org")
			.build();
----

This is more verbose, but by building the `WebClient` with a `MockMvc` instance we have
the full power of `MockMvc` at our fingertips.

[TIP]
====
For additional information on creating a `MockMvc` instance refer to
<<spring-mvc-test-server-setup-options>>.
====

[[spring-mvc-test-server-htmlunit-webdriver]]
===== MockMvc and WebDriver

In the previous sections, we have seen how to use `MockMvc` in conjunction with the raw
HtmlUnit APIs. In this section, we will leverage additional abstractions within the Selenium
https://docs.seleniumhq.org/projects/webdriver/[WebDriver] to make things even easier.

[[spring-mvc-test-server-htmlunit-webdriver-why]]
====== Why WebDriver and MockMvc?

We can already use HtmlUnit and `MockMvc`, so why would we want to use `WebDriver`? The
Selenium `WebDriver` provides a very elegant API that allows us to easily organize our code.
To better understand, let's explore an example.

[NOTE]
====
Despite being a part of https://docs.seleniumhq.org/[Selenium], WebDriver does not require
a Selenium Server to run your tests.
====

Suppose we need to ensure that a message is created properly. The tests involve finding
the HTML form input elements, filling them out, and making various assertions.

This approach results in numerous, separate tests because we want to test error
conditions as well. For example, we want to ensure that we get an error if we fill out
only part of the form. If we fill out the entire form, the newly created message should
be displayed afterwards.

If one of the fields were named "summary", then we might have something like the
following repeated in multiple places within our tests.

[source,java,indent=0]
----
	HtmlTextInput summaryInput = currentPage.getHtmlElementById("summary");
	summaryInput.setValueAttribute(summary);
----

So what happens if we change the `id` to "smmry"? Doing so would force us to update all
of our tests to incorporate this change! Of course, this violates the _DRY Principle_; so
we should ideally extract this code into its own method as follows.

[source,java,indent=0]
----
	public HtmlPage createMessage(HtmlPage currentPage, String summary, String text) {
		setSummary(currentPage, summary);
		// ...
	}

	public void setSummary(HtmlPage currentPage, String summary) {
		HtmlTextInput summaryInput = currentPage.getHtmlElementById("summary");
		summaryInput.setValueAttribute(summary);
	}
----

This ensures that we do not have to update all of our tests if we change the UI.

We might even take this a step further and place this logic within an Object that
represents the `HtmlPage` we are currently on.

[source,java,indent=0]
----
	public class CreateMessagePage {

		final HtmlPage currentPage;

		final HtmlTextInput summaryInput;

		final HtmlSubmitInput submit;

		public CreateMessagePage(HtmlPage currentPage) {
			this.currentPage = currentPage;
			this.summaryInput = currentPage.getHtmlElementById("summary");
			this.submit = currentPage.getHtmlElementById("submit");
		}

		public <T> T createMessage(String summary, String text) throws Exception {
			setSummary(summary);

			HtmlPage result = submit.click();
			boolean error = CreateMessagePage.at(result);

			return (T) (error ? new CreateMessagePage(result) : new ViewMessagePage(result));
		}

		public void setSummary(String summary) throws Exception {
			summaryInput.setValueAttribute(summary);
		}

		public static boolean at(HtmlPage page) {
			return "Create Message".equals(page.getTitleText());
		}
	}
----

Formerly, this pattern is known as the
https://github.com/SeleniumHQ/selenium/wiki/PageObjects[Page Object Pattern]. While we can
certainly do this with HtmlUnit, WebDriver provides some tools that we will explore in the
following sections to make this pattern much easier to implement.

[[spring-mvc-test-server-htmlunit-webdriver-setup]]
====== MockMvc and WebDriver Setup

To use Selenium WebDriver with the Spring MVC Test framework, make sure that your project
includes a test dependency on `org.seleniumhq.selenium:selenium-htmlunit-driver`.

We can easily create a Selenium `WebDriver` that integrates with `MockMvc` using the
`MockMvcHtmlUnitDriverBuilder` as follows.

[source,java,indent=0]
----
	@Autowired
	WebApplicationContext context;

	WebDriver driver;

	@Before
	public void setup() {
		driver = MockMvcHtmlUnitDriverBuilder
				.webAppContextSetup(context)
				.build();
}
----

[NOTE]
====
This is a simple example of using `MockMvcHtmlUnitDriverBuilder`.
For more advanced usage, refer to <<Advanced MockMvcHtmlUnitDriverBuilder>>
====

This will ensure that any URL referencing `localhost` as the server will be directed to
our `MockMvc` instance without the need for a real HTTP connection. Any other URL will be
requested using a network connection as normal. This allows us to easily test the use of
CDNs.

[[spring-mvc-test-server-htmlunit-webdriver-usage]]
====== MockMvc and WebDriver Usage

Now we can use WebDriver as we normally would, but without the need to deploy our
application to a Servlet container. For example, we can request the view to create
a message with the following.

[source,java,indent=0]
----
	CreateMessagePage page = CreateMessagePage.to(driver);
----

We can then fill out the form and submit it to create a message.

[source,java,indent=0]
----
	ViewMessagePage viewMessagePage =
			page.createMessage(ViewMessagePage.class, expectedSummary, expectedText);
----

This improves on the design of our
<<spring-mvc-test-server-htmlunit-mah-usage,HtmlUnit test>> by leveraging the _Page Object
Pattern_. As we mentioned in <<spring-mvc-test-server-htmlunit-webdriver-why>>, we can
use the Page Object Pattern with HtmlUnit, but it is much easier with WebDriver. Let's
take a look at our new `CreateMessagePage` implementation.

[source,java,indent=0]
----
	public class CreateMessagePage
			extends AbstractPage { // <1>

		// <2>
		private WebElement summary;
		private WebElement text;

		// <3>
		@FindBy(css = "input[type=submit]")
		private WebElement submit;

		public CreateMessagePage(WebDriver driver) {
			super(driver);
		}

		public <T> T createMessage(Class<T> resultPage, String summary, String details) {
			this.summary.sendKeys(summary);
			this.text.sendKeys(details);
			this.submit.click();
			return PageFactory.initElements(driver, resultPage);
		}

		public static CreateMessagePage to(WebDriver driver) {
			driver.get("http://localhost:9990/mail/messages/form");
			return PageFactory.initElements(driver, CreateMessagePage.class);
		}
	}
----

<1> The first thing you will notice is that `CreateMessagePage` extends the
`AbstractPage`. We won't go over the details of `AbstractPage`, but in summary it
contains common functionality for all of our pages. For example, if our application has
a navigational bar, global error messages, etc., this logic can be placed in a shared
location.

<2> The next thing you will notice is that we have a member variable for each of the
parts of the HTML page that we are interested in. These are of type `WebElement`.
``WebDriver``'s https://github.com/SeleniumHQ/selenium/wiki/PageFactory[PageFactory] allows
us to remove a lot of code from the HtmlUnit version of `CreateMessagePage` by
automatically resolving each `WebElement`. The
https://seleniumhq.github.io/selenium/docs/api/java/org/openqa/selenium/support/PageFactory.html#initElements-org.openqa.selenium.WebDriver-java.lang.Class-[PageFactory#initElements(WebDriver,Class<T>)]
method will automatically resolve each `WebElement` by using the field name and looking it
up by the `id` or `name` of the element within the HTML page.

<3> We can use the
https://github.com/SeleniumHQ/selenium/wiki/PageFactory#making-the-example-work-using-annotations[@FindBy annotation]
to override the default lookup behavior. Our example demonstrates how to use the `@FindBy`
annotation to look up our submit button using a css selector, *input[type=submit]*.

Finally, we can verify that a new message was created successfully. The following
assertions use the https://code.google.com/p/fest/[FEST assertion library].

[source,java,indent=0]
----
	assertThat(viewMessagePage.getMessage()).isEqualTo(expectedMessage);
	assertThat(viewMessagePage.getSuccess()).isEqualTo("Successfully created a new message");
----

We can see that our `ViewMessagePage` allows us to interact with our custom domain
model. For example, it exposes a method that returns a `Message` object.

[source,java,indent=0]
----
	public Message getMessage() throws ParseException {
		Message message = new Message();
		message.setId(getId());
		message.setCreated(getCreated());
		message.setSummary(getSummary());
		message.setText(getText());
		return message;
	}
----

We can then leverage the rich domain objects in our assertions.

Lastly, don't forget to _close_ the `WebDriver` instance when the test is complete.

[source,java,indent=0]
----
	@After
	public void destroy() {
		if (driver != null) {
			driver.close();
		}
	}
----

For additional information on using WebDriver, refer to the Selenium
https://github.com/SeleniumHQ/selenium/wiki/Getting-Started[WebDriver documentation].

[[spring-mvc-test-server-htmlunit-webdriver-advanced-builder]]
====== Advanced MockMvcHtmlUnitDriverBuilder

In the examples so far, we have used `MockMvcHtmlUnitDriverBuilder` in the simplest way
possible, by building a `WebDriver` based on the `WebApplicationContext` loaded for us by
the Spring TestContext Framework. This approach is repeated here.

[source,java,indent=0]
----
	@Autowired
	WebApplicationContext context;

	WebDriver driver;

	@Before
	public void setup() {
		driver = MockMvcHtmlUnitDriverBuilder
				.webAppContextSetup(context)
				.build();
	}
----

We can also specify additional configuration options.

[source,java,indent=0]
----
	WebDriver driver;

	@Before
	public void setup() {
		driver = MockMvcHtmlUnitDriverBuilder
				// demonstrates applying a MockMvcConfigurer (Spring Security)
				.webAppContextSetup(context, springSecurity())
				// for illustration only - defaults to ""
				.contextPath("")
				// By default MockMvc is used for localhost only;
				// the following will use MockMvc for example.com and example.org as well
				.useMockMvcForHosts("example.com","example.org")
				.build();
}
----

As an alternative, we can perform the exact same setup by configuring the `MockMvc`
instance separately and supplying it to the `MockMvcHtmlUnitDriverBuilder` as follows.

[source,java,indent=0]
----
	MockMvc mockMvc = MockMvcBuilders
			.webAppContextSetup(context)
			.apply(springSecurity())
			.build();

	driver = MockMvcHtmlUnitDriverBuilder
			.mockMvcSetup(mockMvc)
			// for illustration only - defaults to ""
			.contextPath("")
			// By default MockMvc is used for localhost only;
			// the following will use MockMvc for example.com and example.org as well
			.useMockMvcForHosts("example.com","example.org")
			.build();
----

This is more verbose, but by building the `WebDriver` with a `MockMvc` instance we have
the full power of `MockMvc` at our fingertips.

[TIP]
====
For additional information on creating a `MockMvc` instance refer to
<<spring-mvc-test-server-setup-options>>.
====

[[spring-mvc-test-server-htmlunit-geb]]
===== MockMvc and Geb

In the previous section, we saw how to use `MockMvc` with `WebDriver`. In this section,
we will use http://www.gebish.org/[Geb] to make our tests even Groovy-er.

[[spring-mvc-test-server-htmlunit-geb-why]]
====== Why Geb and MockMvc?

Geb is backed by WebDriver, so it offers many of the
<<spring-mvc-test-server-htmlunit-webdriver-why,same benefits>> that we get from
WebDriver. However, Geb makes things even easier by taking care of some of the
boilerplate code for us.

[[spring-mvc-test-server-htmlunit-geb-setup]]
====== MockMvc and Geb Setup

We can easily initialize a Geb `Browser` with a Selenium `WebDriver` that uses `MockMvc`
as follows.

[source,groovy]
----
def setup() {
	browser.driver = MockMvcHtmlUnitDriverBuilder
		.webAppContextSetup(context)
		.build()
}
----

[NOTE]
====
This is a simple example of using `MockMvcHtmlUnitDriverBuilder`.
For more advanced usage, refer to <<Advanced MockMvcHtmlUnitDriverBuilder>>
====

This will ensure that any URL referencing `localhost` as the server will be directed to
our `MockMvc` instance without the need for a real HTTP connection. Any other URL will be
requested using a network connection as normal. This allows us to easily test the use of
CDNs.

[[spring-mvc-test-server-htmlunit-geb-usage]]
====== MockMvc and Geb Usage

Now we can use Geb as we normally would, but without the need to deploy our
application to a Servlet container. For example, we can request the view to create
a message with the following:

[source,groovy]
----
to CreateMessagePage
----

We can then fill out the form and submit it to create a message.

[source,groovy]
----
when:
form.summary = expectedSummary
form.text = expectedMessage
submit.click(ViewMessagePage)
----

Any unrecognized method calls or property accesses/references that are not found will be
forwarded to the current page object. This removes a lot of the boilerplate code we needed
when using WebDriver directly.

As with direct WebDriver usage, this improves on the design of our
<<spring-mvc-test-server-htmlunit-mah-usage,HtmlUnit test>> by leveraging the _Page Object
Pattern_. As mentioned previously, we can use the Page Object Pattern with HtmlUnit and
WebDriver, but it is even easier with Geb. Let's take a look at our new Groovy-based
`CreateMessagePage` implementation.

[source,groovy]
----
class CreateMessagePage extends Page {
	static url = 'messages/form'
	static at = { assert title == 'Messages : Create'; true }
	static content =  {
		submit { $('input[type=submit]') }
		form { $('form') }
		errors(required:false) { $('label.error, .alert-error')?.text() }
	}
}
----

The first thing you will notice is that our `CreateMessagePage` extends `Page`. We won't
go over the details of `Page`, but in summary it contains common functionality for all of
our pages. The next thing you will notice is that we define a URL in which this page can
be found. This allows us to navigate to the page as follows.

[source,groovy]
----
to CreateMessagePage
----

We also have an `at` closure that determines if we are at the specified page. It should return
`true` if we are on the correct page. This is why we can assert that we are on the correct
page as follows.

[source,groovy]
----
then:
at CreateMessagePage
errors.contains('This field is required.')
----

[NOTE]
====
We use an assertion in the closure, so that we can determine where things went wrong if
we were at the wrong page.
====

Next we create a `content` closure that specifies all the areas of interest within the page.
We can use a
http://www.gebish.org/manual/current/#the-jquery-ish-navigator-api[jQuery-ish Navigator API]
to select the content we are interested in.

Finally, we can verify that a new message was created successfully.

[source,groovy]
----
then:
at ViewMessagePage
success == 'Successfully created a new message'
id
date
summary == expectedSummary
message == expectedMessage
----

For further details on how to get the most out of Geb, consult
http://www.gebish.org/manual/current/[The Book of Geb] user's manual.


[[spring-mvc-test-client]]
==== Client-Side REST Tests

Client-side tests can be used to test code that internally uses the `RestTemplate`.
The idea is to declare expected requests and to provide "stub" responses so that
you can focus on testing the code in isolation, i.e. without running a server.
Here is an example:

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	RestTemplate restTemplate = new RestTemplate();

	MockRestServiceServer mockServer = MockRestServiceServer.bindTo(restTemplate).build();
	mockServer.expect(requestTo("/greeting")).andRespond(withSuccess());

	// Test code that uses the above RestTemplate ...

	mockServer.verify();
----

In the above example, `MockRestServiceServer`, the central class for client-side REST
tests, configures the `RestTemplate` with a custom `ClientHttpRequestFactory` that
asserts actual requests against expectations and returns "stub" responses. In this case
we expect a request to "/greeting" and want to return a 200 response with
"text/plain" content. We could define as additional expected requests and stub responses as
needed. When expected requests and stub responses are defined, the `RestTemplate` can be
used in client-side code as usual. At the end of testing `mockServer.verify()` can be
used to verify that all expectations have been satisfied.

By default requests are expected in the order in which expectations were declared.
You can set the `ignoreExpectOrder` option when building the server in which case
all expectations are checked (in order) to find a match for a given request. That
means requests are allowed to come in any order. Here is an example:

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	server = MockRestServiceServer.bindTo(restTemplate).ignoreExpectOrder(true).build();
----

Even with unordered requests by default each request is allowed to execute once only.
The `expect` method provides an overloaded variant that accepts an `ExpectedCount`
argument that specifies a count range, e.g. `once`, `manyTimes`, `max`, `min`,
`between`, and so on. Here is an example:

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	RestTemplate restTemplate = new RestTemplate();

	MockRestServiceServer mockServer = MockRestServiceServer.bindTo(restTemplate).build();
	mockServer.expect(times(2), requestTo("/foo")).andRespond(withSuccess());
	mockServer.expect(times(3), requestTo("/bar")).andRespond(withSuccess());

	// ...

	mockServer.verify();
----

Note that when `ignoreExpectOrder` is not set (the default), and therefore requests
are expected in order of declaration, then that order only applies to the first of
any expected request. For example if "/foo" is expected 2 times followed by "/bar"
3 times, then there should be a request to "/foo" before there is a request to "/bar"
but aside from that subsequent "/foo" and "/bar" requests can come at any time.

As an alternative to all of the above the client-side test support also provides a
`ClientHttpRequestFactory` implementation that can be configured into a `RestTemplate`
to bind it to a `MockMvc` instance. That allows processing requests using actual
server-side logic but without running a server. Here is an example:

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	MockMvc mockMvc = MockMvcBuilders.webAppContextSetup(this.wac).build();
	this.restTemplate = new RestTemplate(new MockMvcClientHttpRequestFactory(mockMvc));

	// Test code that uses the above RestTemplate ...

	mockServer.verify();
----

[[spring-mvc-test-client-static-imports]]
===== Static Imports

Just like with server-side tests, the fluent API for client-side tests requires a few
static imports. Those are easy to find by searching __"MockRest*"__. Eclipse users
should add `"MockRestRequestMatchers.{asterisk}"` and `"MockRestResponseCreators.{asterisk}"`
as "favorite static members" in the Eclipse preferences under
__Java -> Editor -> Content Assist -> Favorites__.
That allows using content assist after typing the first character of the
static method name. Other IDEs (e.g. IntelliJ) may not require any additional
configuration. Just check the support for code completion on static members.

[[spring-mvc-test-client-resources]]
===== Further Examples of Client-side REST Tests

Spring MVC Test's own tests include
https://github.com/spring-projects/spring-framework/tree/master/spring-test/src/test/java/org/springframework/test/web/client/samples[example
tests] of client-side REST tests.



[[testing-examples-petclinic]]
=== PetClinic Example

The PetClinic application, available on
https://github.com/spring-projects/spring-petclinic[GitHub], illustrates several features
of the __Spring TestContext Framework__ in a JUnit 4 environment. Most test functionality
is included in the `AbstractClinicTests`, for which a partial listing is shown below:

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	import static org.junit.Assert.assertEquals;
	// import ...

	**@ContextConfiguration**
	public abstract class AbstractClinicTests **extends AbstractTransactionalJUnit4SpringContextTests** {

		**@Autowired**
		protected Clinic clinic;

		@Test
		public void getVets() {
			Collection<Vet> vets = this.clinic.getVets();
			assertEquals("JDBC query must show the same number of vets",
				**super.countRowsInTable("VETS")**, vets.size());
			Vet v1 = EntityUtils.getById(vets, Vet.class, 2);
			assertEquals("Leary", v1.getLastName());
			assertEquals(1, v1.getNrOfSpecialties());
			assertEquals("radiology", (v1.getSpecialties().get(0)).getName());
			// ...
		}

		// ...
	}
----

Notes:

* This test case extends the `AbstractTransactionalJUnit4SpringContextTests` class, from
  which it inherits configuration for Dependency Injection (through the
  `DependencyInjectionTestExecutionListener`) and transactional behavior (through the
  `TransactionalTestExecutionListener`).
* The `clinic` instance variable -- the application object being tested -- is set by
  Dependency Injection through `@Autowired` semantics.
* The `getVets()` method illustrates how you can use the inherited `countRowsInTable()`
  method to easily verify the number of rows in a given table, thus verifying correct
  behavior of the application code being tested. This allows for stronger tests and
  lessens dependency on the exact test data. For example, you can add additional rows in
  the database without breaking tests.
* Like many integration tests that use a database, most of the tests in
  `AbstractClinicTests` depend on a minimum amount of data already in the database before
  the test cases run. Alternatively, you might choose to populate the database within the
  test fixture set up of your test cases -- again, within the same transaction as the
  tests.

The PetClinic application supports three data access technologies: JDBC, Hibernate, and
JPA. By declaring `@ContextConfiguration` without any specific resource locations, the
`AbstractClinicTests` class will have its application context loaded from the default
location, `AbstractClinicTests-context.xml`, which declares a common `DataSource`.
Subclasses specify additional context locations that must declare a
`PlatformTransactionManager` and a concrete implementation of `Clinic`.

For example, the Hibernate implementation of the PetClinic tests contains the following
implementation. For this example, `HibernateClinicTests` does not contain a single line
of code: we only need to declare `@ContextConfiguration`, and the tests are inherited
from `AbstractClinicTests`. Because `@ContextConfiguration` is declared without any
specific resource locations, the __Spring TestContext Framework__ loads an application
context from all the beans defined in `AbstractClinicTests-context.xml` (i.e., the
inherited locations) and `HibernateClinicTests-context.xml`, with
`HibernateClinicTests-context.xml` possibly overriding beans defined in
`AbstractClinicTests-context.xml`.

[source,java,indent=0]
[subs="verbatim,quotes"]
----
	**@ContextConfiguration**
	public class HibernateClinicTests extends AbstractClinicTests { }
----

In a large-scale application, the Spring configuration is often split across multiple
files. Consequently, configuration locations are typically specified in a common base
class for all application-specific integration tests. Such a base class may also add
useful instance variables -- populated by Dependency Injection, naturally -- such as a
`SessionFactory` in the case of an application using Hibernate.

As far as possible, you should have exactly the same Spring configuration files in your
integration tests as in the deployed environment. One likely point of difference
concerns database connection pooling and transaction infrastructure. If you are
deploying to a full-blown application server, you will probably use its connection pool
(available through JNDI) and JTA implementation. Thus in production you will use a
`JndiObjectFactoryBean` or `<jee:jndi-lookup>` for the `DataSource` and
`JtaTransactionManager`. JNDI and JTA will not be available in out-of-container
integration tests, so you should use a combination like the Commons DBCP
`BasicDataSource` and `DataSourceTransactionManager` or `HibernateTransactionManager`
for them. You can factor out this variant behavior into a single XML file, having the
choice between application server and a 'local' configuration separated from all other
configuration, which will not vary between the test and production environments. In
addition, it is advisable to use properties files for connection settings. See the
PetClinic application for an example.




[[testing-resources]]
== Further Resources

Consult the following resources for more information about testing:

* https://www.junit.org/[JUnit]: "__A programmer-oriented testing framework for Java__".
  Used by the Spring Framework in its test suite.
* http://testng.org/[TestNG]: A testing framework inspired by JUnit with added support
  for annotations, test groups, data-driven testing, distributed testing, etc.
* https://joel-costigliola.github.io/assertj/[AssertJ]: "__Fluent assertions for Java__"
  including support for Java 8 lambdas, streams, etc.
* https://en.wikipedia.org/wiki/Mock_Object[Mock Objects]: Article in Wikipedia.
* http://www.mockobjects.com/[MockObjects.com]: Web site dedicated to mock objects, a
  technique for improving the design of code within test-driven development.
* https://mockito.github.io[Mockito]: Java mock library based on the
  http://xunitpatterns.com/Test%20Spy.html[test spy] pattern.
* http://easymock.org/[EasyMock]: Java library "__that provides Mock Objects for
  interfaces (and objects through the class extension) by generating them on the fly
  using Java's proxy mechanism.__" Used by the Spring Framework in its test suite.
* http://jmock.org/[JMock]: Library that supports test-driven development of Java
  code with mock objects.
* http://dbunit.sourceforge.net/[DbUnit]: JUnit extension (also usable with Ant and
  Maven) targeted for database-driven projects that, among other things, puts your
  database into a known state between test runs.
* http://grinder.sourceforge.net/[The Grinder]: Java load testing framework.
