springboot实现websocket

        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-websocketartifactId>
        dependency>

向容器添加ServerEndpointExporter的bean

@Configuration
public class WebSocketConfiguration {
    /**
     * 	注入ServerEndpointExporter，
     * 	这个bean会自动注册使用了@ServerEndpoint注解声明的Websocket endpoint
     */
    @Bean
    public ServerEndpointExporter serverEndpointExporter() {
        return new ServerEndpointExporter();
    }
}

配置服务端

package com.mqb.yjwj.websocket;

import org.springframework.stereotype.Component;

import javax.websocket.*;
import javax.websocket.server.ServerEndpoint;
import java.io.IOException;
import java.util.concurrent.CopyOnWriteArrayList;

/**
 * @ServerEndPoint 注解是一个类层次的注解，它的功能主要是将目前的类定义成一个websocket服务器端，
 * 注解的值将被用于监听用户连接的终端访问URL地址，客户端可以通过这个URL连接到websocket服务器端
 */
@ServerEndpoint("/websocket")
@Component
public class WebSocketSetvice {
  private static int onlineCount=0;
  private static final CopyOnWriteArrayList<WebSocketSetvice> WEB_SOCKET_SET =new CopyOnWriteArrayList<WebSocketSetvice>();
  private Session session;

  @OnOpen
  public void onOpen(Session session){
    this.session=session;
    WEB_SOCKET_SET.add(this);//加入set中
    addOnlineCount();
    System.out.println("有新连接加入！当前在线人数为"+getOnlineCount());
  }

  @OnClose
  public void onClose(){
    WEB_SOCKET_SET.remove(this);
    subOnlineCount();
    System.out.println("有一连接关闭！当前在线人数为" + getOnlineCount());
  }

  @OnMessage
  public void onMessage(String message,Session session){
    System.out.println("来自客户端的消息："+message);
//        群发消息
    for (WebSocketSetvice item:WEB_SOCKET_SET){
      try {
        item.sendMessage(message);
      } catch (IOException e) {
        e.printStackTrace();
        continue;
      }
    }
  }

  @OnError
  public void onError(Session session, Throwable throwable){
    System.out.println("发生错误！");
    throwable.printStackTrace();
  }
  //   下面是自定义的一些方法
  public void sendMessage(String message) throws IOException {
    this.session.getBasicRemote().sendText(message);
  }

  public static synchronized int getOnlineCount(){
    return onlineCount;
  }
  public static synchronized void addOnlineCount(){
    WebSocketSetvice.onlineCount++;
  }
  public static synchronized void subOnlineCount(){
    WebSocketSetvice.onlineCount--;
  }
}

启动项目，测试websocket
http://www.websocket-test.com/