一起学习Spring boot 2.1.X | 第十九篇：WebSocket

本是古典何须时尚 2024-04-17 19:14 60阅读 0赞

1.POM

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

2.配置WebSocketConfig

import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.web.socket.server.standard.ServerEndpointExporter;
    
    /**
     * 开启WebSocket支持
     * @author zhengkai
     */
    @Configuration
    public class WebSocketConfig {
    
        @Bean
        public ServerEndpointExporter serverEndpointExporter() {
            return new ServerEndpointExporter();
        }
    
    }

3.MyWebSocket

import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    import org.springframework.stereotype.Component;
    import org.springframework.ui.ModelMap;
    import javax.websocket.*;
    import javax.websocket.server.PathParam;
    import javax.websocket.server.ServerEndpoint;
    import java.io.IOException;
    import java.util.concurrent.CopyOnWriteArraySet;
    
    @ServerEndpoint(value = "/websocket")
    @Component
    public class MyWebSocket {
    
        private final static Logger logger = LoggerFactory.getLogger(MyWebSocket.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;
    
        //concurrent包的线程安全Set，用来存放每个客户端对应的MyWebSocket对象。
        private static CopyOnWriteArraySet<MyWebSocket> webSocketSet = new CopyOnWriteArraySet<MyWebSocket>();
    
        //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;
    
        /**
         * 连接建立成功调用的方法
         */
        @OnOpen
        public void onOpen(Session session) {
            try {
                this.session = session;
                System.out.println(this.session.getRequestURI().getHost());
                webSocketSet.add(this);//加入set中
                addOnlineCount();//在线数加1
                System.out.println("当前在线人数为" + getOnlineCount());
                sendMessage("连接成功");
            } catch (Exception e) {
                System.out.println(("WebSocket异常"));
            }
        }
    
        /**
         * 连接关闭调用的方法
         */
        @OnClose
        public void onClose() throws IOException {
            webSocketSet.remove(this);//从set中删除
            subOnlineCount();//在线数减1
            System.out.println(("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(Session session, String message) {
            System.out.println("来自客户端的消息:" + message);
        }
    
        /**
         * 发生错误时调用
         */
        @OnError
        public void onError(Session session, Throwable error) {
            System.out.println("发生错误");
            error.printStackTrace();
        }
    
        /**
         * 实现服务器主动推送
         */
        public void sendMessage(String message) throws IOException {
            ModelMap modelMap = new ModelMap();
            modelMap.put("A","a");
            modelMap.put("B","b");
            this.session.getBasicRemote().sendText(modelMap.toString());
    
        }
    
        /**
         * 群发自定义消息
         * */
        public static void sendInfo(String message,@PathParam("sid") String sid) throws IOException {
            for (MyWebSocket item : webSocketSet) {
                System.out.println(item);
                try {
                    //这里可以设定只推送给这个sid的，为null则全部推送
                    if(sid==null) {
                        item.sendMessage(message);
                    }
                } catch (IOException e) {
                    continue;
                }
            }
        }
    
    
        public static synchronized int getOnlineCount() {
            return onlineCount;
        }
    
    
        public static synchronized void addOnlineCount() {
            MyWebSocket.onlineCount++;
        }
    
        public static synchronized void subOnlineCount() {
            MyWebSocket.onlineCount--;
        }
    
    }

4.如需推送信息

import com.demo.utils.MyWebSocket;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    import java.io.IOException;
    
    @RestController
    public class TestControllwe {
    
        @RequestMapping("/")
        public String Text(){
            try {
                MyWebSocket.sendInfo("Test",null);
            } catch (IOException e) {
                e.printStackTrace();
            }
            return null;
        }
    }

5.打包

POM添加依赖打包

<plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-surefire-plugin</artifactId>
                    <configuration>
                        <skip>true</skip>
                    </configuration>
                </plugin>