WebSocket应用

config

• WebSocketConfig.java

package com.example.spring_boot_websocket.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.server.standard.ServerEndpointExporter;

/**
 * WebSocket配置类
 * 开启WebSocket支持
 */
@Configuration
public class WebSocketConfig {
    @Bean
    public ServerEndpointExporter serverEndpointExporter(){
        return new ServerEndpointExporter();
    }
}

• WebSocketServer.java

package com.example.spring_boot_websocket.config;

import org.springframework.stereotype.Component;

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

/**
 * WebSocket服务端
 */
//客户端向服务器端建立WebSocket连接的URL
@ServerEndpoint("/websocket")
@Component
public class WebSocketServer {
    //静态变量，用来记录当前在线连接数，可选
    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<WebSocketServer> webSocketSet = new CopyOnWriteArraySet<WebSocketServer>();

    //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){
        this.session = session;
        webSocketSet.add(this);
        addOnlineCount();           //在线数加1
        System.out.println("有新窗口开始监听,当前在线人数为" + getOnlineCount());
        try {
            sendMessage("连接成功");
        } catch (IOException e) {
            System.out.println("WebSocket 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
        System.out.println("有连接关闭！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) {
        System.out.println("收到客户端的信息:" + message);
        //群发消息
        for (WebSocketServer item : webSocketSet) {
            try {
                item.sendMessage(message);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    /**
     * @param session
     * @param error
     */
    @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 {
        this.session.getBasicRemote().sendText(message);
    }


    /**
     * 群发自定义消息
     */
    public static void sendInfo(String message) throws IOException {
        System.out.println("推送消息内容:" + message);
        for (WebSocketServer item : webSocketSet) {
            try {
                item.sendMessage(message);
            } catch (IOException e) {
                continue;
            }
        }
    }

    public static synchronized int getOnlineCount() {
        return onlineCount;
    }

    public static synchronized void addOnlineCount() {
        WebSocketServer.onlineCount++;
    }

    public static synchronized void subOnlineCount() {
        WebSocketServer.onlineCount--;
    }
}

Controller

• WebSocketController.java

package com.example.spring_boot_websocket.controller;

import com.example.spring_boot_websocket.config.WebSocketServer;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.servlet.http.HttpServletRequest;
import java.io.IOException;

@RestController
public class WebSocketController {

    @RequestMapping("/socket/push")
    public String pushMsg(HttpServletRequest request) {
        String message = request.getParameter("fuwu");
        try {
            WebSocketServer.sendInfo(message);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return "server";
    }
}

界面

• index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>websocket</title>
</head>
<body>
<h2>websocket</h2>
<h1>服务器端信息显示区</h1>
<textarea id="fuwu" style="width: 200px; height: 300px">

</textarea>
<h1>客户信息输入区</h1>
<textarea id="kehu" style="width: 200px">

</textarea>
<button onclick="myFirst()">发送</button>

<script>
    function myFirst() {
        socket.send(document.getElementById("kehu").value);
        document.getElementById("kehu").value =null;
    }
    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
        socket = new WebSocket("ws://localhost:8080/websocket");
//        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:" + new Date());
        };
        //获得服务器端消息事件
        socket.onmessage = function (msg) {
            console.log(msg.data);
            alert(msg.data);
            document.getElementById("fuwu").value = document.getElementById("fuwu").value+"\n"+ msg.data;
        };
        //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");
        }
    }
</script>

</body>
</html>

• server.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>服务器</title>
</head>
<body>
<h1>
    <form action="/socket/push" name="loginfrom" accept-charset="utf-8" method="post">
            <textarea id="fuwu" name="fuwu">

            </textarea>
        <input type="submit" value="群发" >
    </form>
</h1>
</body>
</html>