websocket实战 - 技术栈

pom

xml 复制代码

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>2.0.53</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-websocket</artifactId>
<!--            <version>1.3.5.RELEASE</version>-->
        </dependency>

前端页面1

：

html 复制代码

<!DOCTYPE HTML>
<html>
<head>
    <title>My WebSocket</title>
</head>

<body>
Welcome<br/>
<input id="text" type="text" />
<button onclick="send()">Send</button>
<button onclick="closeWebSocket()">Close</button>
<div id="message">
</div>
</body>

<script type="text/javascript">
    var websocket = null;

    //判断当前浏览器是否支持WebSocket
    if('WebSocket' in window){
        websocket = new WebSocket("ws://localhost:8080/websocket/1");
    }
    else{
        alert('Not support websocket')
    }

    //连接发生错误的回调方法
    websocket.onerror = function(){
        setMessageInnerHTML("error");
    };

    //连接成功建立的回调方法
    websocket.onopen = function(event){
        setMessageInnerHTML("open");
    }

    //接收到消息的回调方法
    websocket.onmessage = function(event){
        setMessageInnerHTML(event.data);
        //console.log(JSON.parse(event.data))
    }

    //连接关闭的回调方法
    websocket.onclose = function(){
        setMessageInnerHTML("close");
    }

    //监听窗口关闭事件，当窗口关闭时，主动去关闭websocket连接，防止连接还没断开就关闭窗口，server端会抛异常。
    window.onbeforeunload = function(){
        websocket.close();
    }

    //将消息显示在网页上
    function setMessageInnerHTML(innerHTML){
        document.getElementById('message').innerHTML += innerHTML + '<br/>';
    }

    //关闭连接
    function closeWebSocket(){
        websocket.close();
    }

    //发送消息
    function send(){
        var message = document.getElementById('text').value;
        websocket.send(message);
    }
</script>
</html>

前端页面2：

html 复制代码

<!DOCTYPE HTML>
<html>
<head>
    <title>My WebSocket</title>
</head>

<body>
Welcome<br/>
<input id="text" type="text" />
<button onclick="send()">Send</button>
<button onclick="closeWebSocket()">Close</button>
<div id="message">
</div>
</body>

<script type="text/javascript">
    var websocket = null;

    //判断当前浏览器是否支持WebSocket
    if('WebSocket' in window){
        websocket = new WebSocket("ws://localhost:8080/websocket/2");
    }
    else{
        alert('Not support websocket')
    }

    //连接发生错误的回调方法
    websocket.onerror = function(){
        setMessageInnerHTML("error");
    };

    //连接成功建立的回调方法
    websocket.onopen = function(event){
        setMessageInnerHTML("open");
    }

    //接收到消息的回调方法
    websocket.onmessage = function(event){
        setMessageInnerHTML(event.data);
        //console.log(JSON.parse(event.data))
    }

    //连接关闭的回调方法
    websocket.onclose = function(){
        setMessageInnerHTML("close");
    }

    //监听窗口关闭事件，当窗口关闭时，主动去关闭websocket连接，防止连接还没断开就关闭窗口，server端会抛异常。
    window.onbeforeunload = function(){
        websocket.close();
    }

    //将消息显示在网页上
    function setMessageInnerHTML(innerHTML){
        document.getElementById('message').innerHTML += innerHTML + '<br/>';
    }

    //关闭连接
    function closeWebSocket(){
        websocket.close();
    }

    //发送消息
    function send(){
        var message = document.getElementById('text').value;
        websocket.send(message);
    }
</script>
</html>

config配置类：

java 复制代码

package com.example.demo.config;

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

/**
 * @Author LHM
 * @Date 2024/9/27 11:25
 * @Description TODO
 */
@Configuration
public class WebsocketAutoConfig {

    @Bean
    public ServerEndpointExporter endpointExporter() {
        return new ServerEndpointExporter();
    }
}

controller层：

java 复制代码

package com.example.demo.controller;


import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;

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

@Slf4j
@Component
@ServerEndpoint(value = "/websocket/{id}")
public class WebsocketServerEndpoint {
     //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。
    //虽然@Component默认是单例模式的，但springboot还是会为每个websocket连接初始化一个bean，所以可以用一个静态set保存起来。
    public static CopyOnWriteArraySet<WebsocketServerEndpoint> websocketServerSet
            = new CopyOnWriteArraySet<>();

    //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;

    //会话窗口的ID标识
    private String id = "";
    
     /**
     * 链接成功调用的方法
     */
     @OnOpen
    public void onOpen(Session session, @PathParam("id") String id) {
        log.info("onOpen >> 链接成功");
        this.session = session;
        //将当前websocket对象存入到Set集合中
        websocketServerSet.add(this);
        //在线人数+1
        addOnlineCount();
        log.info("有新窗口开始监听：" + id + ", 当前在线人数为：" + getOnlineCount());
        this.id = id;
        try {

            sendMessage("有新窗口开始监听：" + id + ", 当前在线人数为：" + getOnlineCount());
        } catch (Exception e) {
            log.error(e.toString());
        }


    }
     /**
     * 链接关闭调用的方法
     */
    @OnClose
    public void onClose() {
        log.info("onClose >> 链接关闭");
        //移除当前Websocket对象
        websocketServerSet.remove(this);
        //在内线人数-1
        subOnLineCount();
        log.info("链接关闭，当前在线人数：" + getOnlineCount());
    }
     /**
     * 收到客户端消息后调用的方法
     *
     * @param message
     * @param session
     */
    @OnMessage
    public void onMessage(String message, Session session) {
        log.info("接收到窗口：" + id + " 的信息：" + message);

        //发送信息
        for (WebsocketServerEndpoint websocketServerEndpoint : websocketServerSet) {
            try {
                websocketServerEndpoint.sendMessage("接收到窗口：" + id + " 的信息：" + message);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

    @OnError
    public void onError(Session session, Throwable e) {
        e.printStackTrace();
    }
    /**
     * 推送消息
     *
     * @param message
     */
    public void sendMessage(String message) throws IOException {
        this.session.getBasicRemote().sendText(message);
    }
    
    private void subOnLineCount() {
        WebsocketServerEndpoint.onlineCount--;
    }

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

    private void addOnlineCount() {
        WebsocketServerEndpoint.onlineCount++;
    }

    private void sendObject(Object object) throws IOException, EncodeException {
        this.session.getBasicRemote().sendObject(object);
    }
//　  /**　id为null时是群发
//     * @param map
//     * @param id
//     */
    public static void sendData(String id, Object map) {
        for (WebsocketServerEndpoint endpoint : websocketServerSet) {
            try {
                if (id == null) {
                    endpoint.sendObject(map);
                } else if (endpoint.id.equals(id)) {
                    endpoint.sendObject(map);
                }
            } catch (Exception e) {
                e.printStackTrace();
                continue;
            }
        }
    }



}

发送数据：

java 复制代码

package com.example.demo.demos;


import com.example.demo.controller.WebsocketServerEndpoint;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.annotation.EnableScheduling;
import org.springframework.scheduling.annotation.Scheduled;

import java.util.concurrent.CopyOnWriteArraySet;

@Slf4j
@Configuration
@EnableScheduling
public class SendMessageToWeb {
//    @Autowired
//    WebsocketServerEndpoint websocketServerEndpoint;
 
    //每10秒发送一次
    @Scheduled(cron = "0/10 * * * * ?")
    public void sendTestMessage() {
        if(WebsocketServerEndpoint.websocketServerSet.size()>0){
            log.info("发送数据");
            try{
                //这里省略获取到需要发送数据data的逻辑  
                CopyOnWriteArraySet<WebsocketServerEndpoint> set =  WebsocketServerEndpoint.websocketServerSet;
                       for (WebsocketServerEndpoint s:set) {
                        s.sendMessage("zzz:" + System.currentTimeMillis());
                       }
            }catch (Exception e){
                log.error(e.getMessage());
            }
        }
    }
}