@SendToUser supported on the class level

Issue: SPR-12047

spring-messaging/src/main/java/org/springframework/messaging/simp/annotation/SendToUser.java

 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -30,6 +30,9 @@ import org.springframework.core.annotation.AliasFor;
  * destination(s) prepended with <code>"/user/{username}"</code> where the user name
  * is extracted from the headers of the input message being handled.
  *
+ * <p>The annotation may also be placed at class-level in which case all methods
+ * in the class where the annotation applies will inherit it.
+
  * @author Rossen Stoyanchev
  * @author Sam Brannen
  * @since 4.0
@@ -37,7 +40,7 @@ import org.springframework.core.annotation.AliasFor;
  * @see org.springframework.messaging.simp.user.UserDestinationMessageHandler
  * @see org.springframework.messaging.simp.SimpMessageHeaderAccessor#getUser()
  */
-@Target(ElementType.METHOD)
+@Target({ElementType.METHOD, ElementType.TYPE})
 @Retention(RetentionPolicy.RUNTIME)
 @Documented
 public @interface SendToUser {

spring-messaging/src/main/java/org/springframework/messaging/simp/annotation/support/SendToMethodReturnValueHandler.java

@@ -134,7 +134,8 @@ public class SendToMethodReturnValueHandler implements HandlerMethodReturnValueH
 	public boolean supportsReturnType(MethodParameter returnType) {
 		if (returnType.getMethodAnnotation(SendTo.class) != null ||
 				AnnotationUtils.getAnnotation(returnType.getDeclaringClass(), SendTo.class) != null ||
-				returnType.getMethodAnnotation(SendToUser.class) != null) {
+				returnType.getMethodAnnotation(SendToUser.class) != null ||
+				AnnotationUtils.getAnnotation(returnType.getDeclaringClass(), SendToUser.class) != null) {
 			return true;
 		}
 		return (!this.annotationRequired);
@@ -149,7 +150,7 @@ public class SendToMethodReturnValueHandler implements HandlerMethodReturnValueH
 		MessageHeaders headers = message.getHeaders();
 		String sessionId = SimpMessageHeaderAccessor.getSessionId(headers);
 		PlaceholderResolver varResolver = initVarResolver(headers);
-		SendToUser sendToUser = returnType.getMethodAnnotation(SendToUser.class);
+		SendToUser sendToUser = getSendToUser(returnType);
 
 		if (sendToUser != null) {
 			boolean broadcast = sendToUser.broadcast();
@@ -184,6 +185,18 @@ public class SendToMethodReturnValueHandler implements HandlerMethodReturnValueH
 		}
 	}
 
+	private SendToUser getSendToUser(MethodParameter returnType) {
+		SendToUser annot = returnType.getMethodAnnotation(SendToUser.class);
+		if (annot != null && !ObjectUtils.isEmpty((annot.value()))) {
+			return annot;
+		}
+		SendToUser typeAnnot = AnnotationUtils.getAnnotation(returnType.getDeclaringClass(), SendToUser.class);
+		if (typeAnnot != null && !ObjectUtils.isEmpty((typeAnnot.value()))) {
+			return typeAnnot;
+		}
+		return (annot != null ? annot : typeAnnot);
+	}
+
 	private SendTo getSendTo(MethodParameter returnType) {
 		SendTo sendTo = returnType.getMethodAnnotation(SendTo.class);
 		if (sendTo != null && !ObjectUtils.isEmpty((sendTo.value()))) {

spring-messaging/src/test/java/org/springframework/messaging/simp/annotation/support/SendToMethodReturnValueHandlerTests.java

@@ -91,6 +91,9 @@ public class SendToMethodReturnValueHandlerTests {
 	private MethodParameter defaultNoAnnotation;
 	private MethodParameter defaultEmptyAnnotation;
 	private MethodParameter defaultOverrideAnnotation;
+	private MethodParameter userDefaultNoAnnotation;
+	private MethodParameter userDefaultEmptyAnnotation;
+	private MethodParameter userDefaultOverrideAnnotation;
 
 
 	@Before
@@ -133,14 +136,23 @@ public class SendToMethodReturnValueHandlerTests {
 		method = this.getClass().getDeclaredMethod("handleAndSendToJsonView");
 		this.jsonViewReturnType = new SynthesizingMethodParameter(method, -1);
 
-		method = TestBean.class.getDeclaredMethod("handleNoAnnotation");
+		method = SendToTestBean.class.getDeclaredMethod("handleNoAnnotation");
 		this.defaultNoAnnotation = new SynthesizingMethodParameter(method, -1);
 
-		method = TestBean.class.getDeclaredMethod("handleAndSendToDefaultDestination");
+		method = SendToTestBean.class.getDeclaredMethod("handleAndSendToDefaultDestination");
 		this.defaultEmptyAnnotation = new SynthesizingMethodParameter(method, -1);
 
-		method = TestBean.class.getDeclaredMethod("handleAndSendToOverride");
+		method = SendToTestBean.class.getDeclaredMethod("handleAndSendToOverride");
 		this.defaultOverrideAnnotation = new SynthesizingMethodParameter(method, -1);
+
+		method = SendToUserTestBean.class.getDeclaredMethod("handleNoAnnotation");
+		this.userDefaultNoAnnotation = new SynthesizingMethodParameter(method, -1);
+
+		method = SendToUserTestBean.class.getDeclaredMethod("handleAndSendToDefaultDestination");
+		this.userDefaultEmptyAnnotation = new SynthesizingMethodParameter(method, -1);
+
+		method = SendToUserTestBean.class.getDeclaredMethod("handleAndSendToOverride");
+		this.userDefaultOverrideAnnotation = new SynthesizingMethodParameter(method, -1);
 	}
 
 
@@ -154,6 +166,10 @@ public class SendToMethodReturnValueHandlerTests {
 		assertTrue(this.handler.supportsReturnType(this.defaultNoAnnotation));
 		assertTrue(this.handler.supportsReturnType(this.defaultEmptyAnnotation));
 		assertTrue(this.handler.supportsReturnType(this.defaultOverrideAnnotation));
+
+		assertTrue(this.handler.supportsReturnType(this.userDefaultNoAnnotation));
+		assertTrue(this.handler.supportsReturnType(this.userDefaultEmptyAnnotation));
+		assertTrue(this.handler.supportsReturnType(this.userDefaultOverrideAnnotation));
 	}
 
 	@Test
@@ -230,6 +246,44 @@ public class SendToMethodReturnValueHandlerTests {
 		assertResponse(this.defaultOverrideAnnotation, sessionId, 1, "/dest4");
 	}
 
+	@Test
+	public void sendToUserClassDefaultNoAnnotation() throws Exception {
+		given(this.messageChannel.send(any(Message.class))).willReturn(true);
+
+		String sessionId = "sess1";
+		Message<?> inputMessage = createInputMessage(sessionId, "sub1", null, null, null);
+		this.handler.handleReturnValue(PAYLOAD, this.userDefaultNoAnnotation, inputMessage);
+
+		verify(this.messageChannel, times(1)).send(this.messageCaptor.capture());
+		assertResponse(this.userDefaultNoAnnotation, sessionId, 0, "/user/sess1/dest-default");
+	}
+
+	@Test
+	public void sendToUserClassDefaultEmptyAnnotation() throws Exception {
+		given(this.messageChannel.send(any(Message.class))).willReturn(true);
+
+		String sessionId = "sess1";
+		Message<?> inputMessage = createInputMessage(sessionId, "sub1", null, null, null);
+		this.handler.handleReturnValue(PAYLOAD, this.userDefaultEmptyAnnotation, inputMessage);
+
+		verify(this.messageChannel, times(1)).send(this.messageCaptor.capture());
+		assertResponse(this.userDefaultEmptyAnnotation, sessionId, 0, "/user/sess1/dest-default");
+	}
+
+	@Test
+	public void sendToUserClassDefaultOverride() throws Exception {
+		given(this.messageChannel.send(any(Message.class))).willReturn(true);
+
+		String sessionId = "sess1";
+		Message<?> inputMessage = createInputMessage(sessionId, "sub1", null, null, null);
+		this.handler.handleReturnValue(PAYLOAD, this.userDefaultOverrideAnnotation, inputMessage);
+
+		verify(this.messageChannel, times(2)).send(this.messageCaptor.capture());
+		assertResponse(this.userDefaultOverrideAnnotation, sessionId, 0, "/user/sess1/dest3");
+		assertResponse(this.userDefaultOverrideAnnotation, sessionId, 1, "/user/sess1/dest4");
+	}
+
+
 	private void assertResponse(MethodParameter methodParameter, String sessionId,
 			int index, String destination) {
 		SimpMessageHeaderAccessor accessor = getCapturedAccessor(index);
@@ -537,8 +591,8 @@ public class SendToMethodReturnValueHandlerTests {
 		return payload;
 	}
 
-	@SendTo("/dest-default")
-	private static class TestBean {
+	@SendTo("/dest-default") @SuppressWarnings("unused")
+	private static class SendToTestBean {
 
 		public String handleNoAnnotation() {
 			return PAYLOAD;
@@ -556,6 +610,25 @@ public class SendToMethodReturnValueHandlerTests {
 
 	}
 
+	@SendToUser("/dest-default") @SuppressWarnings("unused")
+	private static class SendToUserTestBean {
+
+		public String handleNoAnnotation() {
+			return PAYLOAD;
+		}
+
+		@SendToUser
+		public String handleAndSendToDefaultDestination() {
+			return PAYLOAD;
+		}
+
+		@SendToUser({"/dest3", "/dest4"})
+		public String handleAndSendToOverride() {
+			return PAYLOAD;
+		}
+
+	}
+
 
 	private interface MyJacksonView1 {}
 	private interface MyJacksonView2 {}

src/asciidoc/web-websocket.adoc

@@ -1700,7 +1700,8 @@ than their name and the generic destination. This is also supported through an
 annotation as well as a messaging template.
 
 For example, a message-handling method can send messages to the user associated with
-the message being handled through the `@SendToUser` annotation:
+the message being handled through the `@SendToUser` annotation (also supported on
+the class-level to share a common destination):
 
 [source,java,indent=0]
 [subs="verbatim,quotes"]

src/asciidoc/whats-new.adoc

@@ -671,7 +671,7 @@ Spring 4.3 also improves the caching abstraction as follows:
 
 === WebSocket Messaging Improvements
 
-* `@SendTo` can now be specified at class-level to share a common destination.
+* `@SendTo` and `@SendToUser` can now be specified at class-level to share a common destination.
 
 === Testing Improvements