springboot集成WebSocket向指定用户发送消息（亲测可用！）

- 日理万妓 2024-04-18 22:22 52阅读 0赞

依赖

<dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-websocket</artifactId>
            </dependency>

配置类

package com.yupont.xc.config;
    
    import org.apache.catalina.session.StandardSessionFacade;
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.web.socket.server.standard.ServerEndpointExporter;
    
    import javax.servlet.http.HttpSession;
    import javax.websocket.HandshakeResponse;
    import javax.websocket.server.HandshakeRequest;
    import javax.websocket.server.ServerEndpointConfig;
    
    @Configuration
    public class WebSocketConfig extends ServerEndpointConfig.Configurator { 
         private static final Logger log = LoggerFactory.getLogger(WebSocketConfig.class);
        @Override
        /** * 修改握手信息 */
        public void modifyHandshake(ServerEndpointConfig sec, HandshakeRequest request, HandshakeResponse response) { 
            StandardSessionFacade ssf = (StandardSessionFacade) request.getHttpSession();
            if (ssf != null) { 
                       HttpSession httpSession = (HttpSession) request.getHttpSession();
                      //关键操作
                      sec.getUserProperties().put("sessionId", httpSession.getId());
                log.info("获取到的SessionID：" + httpSession.getId());
                     }
            super.modifyHandshake(sec, request, response);
    
        }
        @Bean
       public ServerEndpointExporter serverEndpointExporter() { 
                 //这个对象说一下，貌似只有服务器是tomcat的时候才需要配置,具体我没有研究
                return new ServerEndpointExporter();
              }
    }

核心类

package com.yupont.xc.task;
    
    import java.io.IOException;
    import java.util.concurrent.ConcurrentHashMap;
    import java.util.concurrent.CopyOnWriteArraySet;
    
    import javax.websocket.*;
    
    import javax.websocket.server.PathParam;
    import javax.websocket.server.ServerEndpoint;
    
    
    import com.yupont.xc.config.WebSocketConfig;
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    import org.springframework.stereotype.Component;
    
    
    @ServerEndpoint(value = "/websocket/{id}", configurator = WebSocketConfig.class)
    @Component
    public class WebSocketServer { 
    
        static Logger log = LoggerFactory.getLogger(WebSocketServer.class);
        //静态变量，用来记录当前在线连接数。应该把它设计成线程安全的。
        private static int onlineCount = 0;
    
        private static ConcurrentHashMap<String, WebSocketServer> webSocketSet = new ConcurrentHashMap<>();
        //与某个客户端的连接会话，需要通过它来给客户端发送数据
        private Session session;
    
        //指定的sid，具有唯一性，暫定為用戶id
        private String sid = "";
    
        /** * 连接建立成功调用的方法 */
        @OnOpen
        public void onOpen(@PathParam("id") String id, Session session, EndpointConfig config) { 
            //获取WebsocketConfig.java中配置的“sessionId”信息值
            String httpSessionId = (String) config.getUserProperties().get("sessionId");
            this.session = session;
            this.sid=id;
    
    
            webSocketSet.put(sid,this);     //加入set中
            addOnlineCount();           //在线数加1
            System.out.println("用戶"+sid+"加入！当前在线人数为" + getOnlineCount());
            try { 
                sendMessage("Hello world");
            } catch (IOException e) { 
                System.out.println("IO异常");
            }
        }
    
        /** * 连接关闭调用的方法 */
        @OnClose
        public void onClose() { 
            webSocketSet.remove(this);  //从set中删除
            subOnlineCount();           //在线数减1
            log.info("有一连接关闭！当前在线人数为" + getOnlineCount());
        }
    
        /** * 收到客户端消息后调用的方法 * * @param message 客户端发送过来的消息 */
        @OnMessage
        public void onMessage(String message, Session session) { 
            log.info("收到来自窗口" + sid + "的信息:" + message);
            //群发消息
        }
    
        /** * @param session * @param error */
        @OnError
        public void onError(Session session, Throwable error) { 
            log.error("发生错误");
            error.printStackTrace();
        }
    
        /** * 实现服务器主动推送 */
        public void sendMessage(String message) throws IOException { 
            this.session.getBasicRemote().sendText(message);
        }
    
    
        /** * */
        public  boolean sendtoUser(String message,String sendUserId) throws IOException { 
           if(sendUserId==null){ 
               for (String key : webSocketSet.keySet()) { 
                   try { 
                       webSocketSet.get(key).sendMessage(message);
    
                   } catch (IOException e) { 
                       e.printStackTrace();
    
                   }
               }
    
    
           }else { 
               if (webSocketSet.get(sendUserId) != null) { 
                   if(!sid.equals(sendUserId)){ 
                       log.info("未找到匹配用戶");
                       return false;
                   }{ 
                       webSocketSet.get(sendUserId).sendMessage(message);
                       try { 
                           Thread.sleep(100);
                       } catch (InterruptedException e) { 
                           e.printStackTrace();
                       }
                       log.info("消息發送成功");
                       return true;
                   }
               } else { 
                   //如果用户不在线则返回不在线信息给自己
                   log.info("未找到匹配用戶");
                   return false;
               }
           }
            return true;
        }
    
    
        public static synchronized int getOnlineCount() { 
            return onlineCount;
        }
    
        public static synchronized void addOnlineCount() { 
            WebSocketServer.onlineCount++;
        }
    
        public static synchronized void subOnlineCount() { 
            WebSocketServer.onlineCount--;
        }
    }

调用时html写法  
注意到评论区的一些问题，统一解答：请求连接中的12是具有唯一性的客户端ID，你可以定义为用户ID，也可以是UUID，不能重复，否则服务器无法定位到客户端，或者多台客户端在服务器却只显示一台

<!DOCTYPE html>
    <html>
    
    <head>
    <title>Title of the document</title>
    <script src="jquery-1.8.3.js"></script>
    </head>
    
    <body>
    The content of the document......
    </body>
     <script> var socket; if(typeof(WebSocket) == "undefined") { console.log("您的浏览器不支持WebSocket"); }else{ console.log("您的浏览器支持WebSocket"); //实现化WebSocket对象，指定要连接的服务器地址与端口 建立连接 //等同于socket = new WebSocket("ws://localhost:8087//websocket"); socket = new WebSocket("ws://localhost:8087/websocket/12"); //打开事件 socket.onopen = function() { console.log("Socket 已打开"); socket.send("这是来自客户端的消息"); }; //获得消息事件 socket.onmessage = function(msg) { console.log(msg.data); //发现消息进入 开始处理前端触发逻辑 }; //关闭事件 socket.onclose = function() { console.log("Socket已关闭"); }; //发生了错误事件 socket.onerror = function() { alert("Socket发生了错误"); //此时可以尝试刷新页面 } //离开页面时，关闭socket //jquery1.8中已经被废弃，3.0中已经移除 // $(window).unload(function(){ // socket.close(); //}); } </script> 
    </html>
    
      
    不要导错参数包哟