平时我们使用webSocket，一般都是浏览器作为客户端，java后端充当服务端，后端推送数据给前端，用于消息推送。这里说明的是另一种情况，一个服务端作为webSocket的server,另一个java服务端作为webSocket的client，这里面也有消息推送，不过是从一个服务推送到另一个服务，这里面没有前端什么事。话不多说，马上开始吧。
首先引入webSocket相关的pom：

<dependency>
     <groupId>org.springframework.boot</groupId>
     <artifactId>spring-boot-starter-websocket</artifactId>
 </dependency>
 <dependency>
     <groupId>org.java-websocket</groupId>
     <artifactId>Java-WebSocket</artifactId>
     <version>1.3.5</version>
 </dependency>

java代码：

import com.alibaba.fastjson.JSONObject;
import org.java_websocket.WebSocket;
import org.java_websocket.client.WebSocketClient;
import org.java_websocket.drafts.Draft_6455;
import org.java_websocket.handshake.ServerHandshake;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.Date;
import java.util.List;

@Component
public class MyWebSocketClient implements InitializingBean {

    private static final Logger logger = LoggerFactory.getLogger(MyWebSocketClient.class);

    private WebSocketClient client;

    public MyWebSocketClient() { }

    @Override
    public void afterPropertiesSet() throws Exception {
        createClient();
    }

    public void createClient(){
        try {
            client = new WebSocketClient(new URI(url),new Draft_6455()) {
                @Override
                public void onOpen(ServerHandshake serverHandshake) {
                    logger.info("连接成功");
                    //可以向webSocket server发送消息
                   client.send(xxxx);
                }

              //接收消息
                @Override
                public void onMessage(String msg) {
                    if(null!=msg&&!msg.trim().equals("")){
                        if(msg.equals("over")){
                            client.close();
                        }
                        try {
                           //对消息做业务处理
                        } catch (Exception e) {
                            e.printStackTrace();
                        }
                    }
                }

                @Override
                public void onClose(int i, String s, boolean b) {
                    logger.info("连接已关闭");
                }

                @Override
                public void onError(Exception e){
                    logger.error("发生错误，关闭");
                    new MyWebSocketClient().createClient();//谨慎加这句  无限循环的可能
                }
            };
        } catch (URISyntaxException e) {
            e.printStackTrace();
        }

        client.connect();
        while(!client.getReadyState().equals(WebSocket.READYSTATE.OPEN)){
            logger.info("正在连接");
        }
    }
}