<dependency>
        <groupId>cn.rongcloud.im</groupId>
        <artifactId>server-sdk-java</artifactId>
        <version>4.0.9</version>
    </dependency>

    compile group: 'cn.rongcloud.im', name: 'server-sdk-java', version: '4.0.9'

   1. Download or clone `server-sdk-java`
   
   2. Navigate to the `server-sdk-java` directory
   
   3. Install dependencies with `mvn install`
   
   4. Package with `mvn clean package`

  String appKey = "appKey";
  String appSecret = "appSecret";
      
  // Initialize the RongCloud SDK, Set up the data center you use.
  RongCloud rongCloud = RongCloud.getInstance(appKey, appSecret，CenterEnum.BJ);
  User user = rongCloud.user;

  /**
  *
  * Register a user and generate a unique Token in RongCloud
  */
  UserModel userModel = new UserModel()
            .setId("hHjap87")
            .setName("RongCloud")
            .setPortrait("http://www.rongcloud.cn/images/logo.png");
  TokenResult result = user.register(userModel);
  System.out.println("getToken: " + result.toString());

# Print result
# getToken: {"reqBody":"userId=userxxd2&name=username&portraitUri=http%3A%2F%2Fwww.rongcloud.cn%2Fimages%2Flogo.png","code":1002,"errorMessage":"Invalidate App-Key.","requestId":"0c1f127e9bc1401bb05eaad61b4502f7"}