update the way to install Java SDK

doc/JAVA_SDK.md

@@ -20,7 +20,22 @@ The following table shows compatibilities between Paddle Serving Server and Java
 
 ### Install Java SDK
 
-You can use Apache Maven to download the SDK.
+You can download jar and install it to the local Maven repository:
+
+```shell
+wget https://paddle-serving.bj.bcebos.com/jar/paddle-serving-sdk-java-0.0.1.jar
+mvn install:install-file -Dfile=$PWD/paddle-serving-sdk-java-0.0.1.jar -DgroupId=io.paddle.serving.client -DartifactId=paddle-serving-sdk-java -Dversion=0.0.1 -Dpackaging=jar
+```
+
+Or compile from the source code and install it to the local Maven repository:
+
+```shell
+cd Serving/java
+mvn compile
+mvn install
+```
+
+### Maven configure
 
 ```text
  <dependency>

doc/JAVA_SDK_CN.md

@@ -22,7 +22,22 @@ Paddle Serving 提供了 Java SDK，支持 Client 端用 Java 语言进行预测
 
 ### 安装
 
-您可以使用 Apache Maven 下载该 SDK。 
+您可以直接下载 jar，安装到本地 Maven 库：
+
+```shell
+wget https://paddle-serving.bj.bcebos.com/jar/paddle-serving-sdk-java-0.0.1.jar
+mvn install:install-file -Dfile=$PWD/paddle-serving-sdk-java-0.0.1.jar -DgroupId=io.paddle.serving.client -DartifactId=paddle-serving-sdk-java -Dversion=0.0.1 -Dpackaging=jar
+```
+
+或者从源码进行编译，安装到本地 Maven 库：
+
+```shell
+cd Serving/java
+mvn compile
+mvn install
+```
+
+### Maven 配置
 
 ```text
  <dependency>
@@ -33,6 +48,8 @@ Paddle Serving 提供了 Java SDK，支持 Client 端用 Java 语言进行预测
 ```
 
 
+
+
 ## 使用样例
 
 这里将展示如何使用 Java SDK 进行房价预测，更多例子详见 [examples](../java/examples) 文件夹。