springboot+websocket简单实现

Dear 丶 2022-05-30 02:44 228阅读 0赞

在maven项目添加依赖

<dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
        <version>1.5.4.RELEASE</version>
    </dependency>

在ftl页面里设置websocket,可以使用websocket.js来进行连接，也可以写个简单websocket的连接

在springboot中需要配置一项文件    这样就可以使用注解来实现

@Configuration
    public class WebSocketConfig {
    
        @Bean
        public ServerEndpointExporter serverEndpointExporter(){
            return new ServerEndpointExporter();
        }
    }

java实现类

@ServerEndpoint(value = "/websocket")
    @Component
    public class MyWebSocket {
    
        //统计在线人数
        private static int onlineCount = 0;
    
        //用本地线程保存session
        private static ThreadLocal<Session> sessions = new ThreadLocal<Session>();
    
        //保存所有连接上的session
        private static Map<String, Session> sessionMap = new ConcurrentHashMap<String, Session>();
    
        public static synchronized int getOnlineCount() {
            return onlineCount;
        }
    
        public static synchronized void addOnlineCount() {
            onlineCount++;
        }
    
        public static synchronized void subOnlineCount() {
            onlineCount--;
        }
    
        //连接
        @OnOpen
        public void onOpen(Session session) {
            sessions.set(session);
            addOnlineCount();
            sessionMap.put(session.getId(), session);
            System.out.println("【" + session.getId() + "】连接上服务器======当前在线人数【" + getOnlineCount() + "】");
            //连接上后给客户端一个消息
            sendMsg(session, "连接服务器成功！");
        }
    
        //关闭
        @OnClose
        public void onClose(Session session) {
            subOnlineCount();
            sessionMap.remove(session.getId());
            System.out.println("【" + session.getId() + "】退出了连接======当前在线人数【" + getOnlineCount() + "】");
        }
    
        //接收消息   客户端发送过来的消息
        @OnMessage
        public void onMessage(String message, Session session) {
            System.out.println("【" + session.getId() + "】客户端的发送消息======内容【" + message + "】");
            String[] split = message.split(",");
            String sessionId = split[0];
            Session ss = sessionMap.get(sessionId);
            if (ss != null) {
                String msgTo = "【" + session.getId() + "】发送给【您】的消息:\n【" + split[1] + "】";
                String msgMe = "【我】发送消息给【"+ss.getId()+"】:\n"+split[1];
                sendMsg(ss, msgTo);
                sendMsg(session,msgMe);
            }else {
                for (Session s : sessionMap.values()) {
                    if (!s.getId().equals(session.getId())) {
                        sendMsg(s, "【" + session.getId() + "】发送给【您】的广播消息:\n【" + message + "】");
                    } else {
                        sendMsg(session,"【我】发送广播消息给大家\n"+message);
                    }
                }
            }
    
        }
    
        //异常
        @OnError
        public void onError(Session session, Throwable throwable) {
            System.out.println("发生异常!");
            throwable.printStackTrace();
        }
    
    
    
        //统一的发送消息方法
        public synchronized void sendMsg(Session session, String msg) {
            try {
                session.getBasicRemote().sendText(msg);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }