springBoot 搭建websocke 实现群聊，点对点聊天等开发

这几天研究JAVA的springBoot，顺便把websocket也搭建了，发现网上相关文档较下，参考网上资料，与自己的想法，写下以下搭建方法以做方便查看

1、依赖

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>

        <dependency>
            <!-- websocket -->
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-websocket</artifactId>
        </dependency>
        <dependency>
            <groupId>com.google.guava</groupId>
            <artifactId>guava</artifactId>
            <version>27.1-jre</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.35</version>
        </dependency>

2、添加websocket配置类WebSocketConfig

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

@Configuration
public class WebSocketConfig {

    /**
     * 注入一个ServerEndpointExporter,该Bean会自动注册使用@ServerEndpoint注解申明的websocket endpoint
     */
    @Bean
    public ServerEndpointExporter serverEndpointExporter() {
        return new ServerEndpointExporter();
    }

}

3、WebSocket类

package com.projuct.junlaishun.Controller.websocket;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
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.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * 前后端交互的类实现消息的接收推送
 *
 * @ServerEndpoint(value = "/ws/{userId}") 前端通过此URI 和后端交互，建立连接,userId为用户id
 */
@Slf4j
@ServerEndpoint(value = "/ws/{userId}")
@Component
public class WebSocket {
    private Map<String,Integer> NAMES;

    /** 记录当前在线连接数 */
    private static AtomicInteger onlineCount = new AtomicInteger(0);

    /** 存放所有在线的客户端 */
    private static Map<String, Session> clients = new ConcurrentHashMap<>();

    /**
     * 连接建立成功调用的方法
     */
    @OnOpen

    public void onOpen(Session session,@PathParam("userId") String userId) {
        onlineCount.incrementAndGet(); // 在线数加1
        clients.put(userId, session);
        log.info("有新连接加入：{}，当前在线人数为：{},用户id:{}", session.getId(), onlineCount.get(),userId);
    }

    /**
     * 连接关闭调用的方法
     */
    @OnClose
    public void onClose(Session session,@PathParam("userId") String userId) {
        onlineCount.decrementAndGet(); // 在线数减1
        clients.remove(userId);
        log.info("有一连接关闭：{}，当前在线人数为：{}", session.getId(), onlineCount.get());
    }

    /**
     * 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
     * 这里能过地址获取用户userId与ws session关联至map中
     */
    @OnMessage
    public void onMessage(String message, Session session,@PathParam("userId") String userId) {
        log.info("服务端收到客户端[{}]的消息[{}]", session.getId(), message);
        try {
            JSONObject myMessage = JSON.parseObject(message);
            if (myMessage != null) {
                Session toSession = null;
                if(myMessage.getString("userId") != null){
                    toSession = clients.get(myMessage.getString("userId")); //取到接收userId session
                }
                if (toSession != null) {
                    this.sendMessage(myMessage.get("message").toString(), toSession);
                }else{
                    log.info("type:"+myMessage.getString("type"));
                    if (myMessage.getString("type").equals("all")){
                        //群发
                        this.sendMessageAll(myMessage.get("message").toString(),userId);
                    }else{
                        log.error("session不存在");
                    }

                }
            }
        } catch (Exception e) {
            log.error("解析失败：{}", e);
        }
    }

    @OnError
    public void onError(Session session, Throwable error) {
        log.error("发生错误");
        error.printStackTrace();
    }

    /**
     * 服务端发送消息给客户端
     */
    private void sendMessage(String message, Session toSession) {
        try {
            log.info("服务端给客户端[{}]发送消息[{}]", toSession.getId(), message);
            toSession.getBasicRemote().sendText(message);
        } catch (Exception e) {
            log.error("服务端发送消息给客户端失败：{}", e);
        }
    }
    /**
     * 群发消息
     *
     * @param message
     * 消息内容
     */
    private void sendMessageAll(String message, String userId) {
        for (Map.Entry<String, Session> sessionEntry : clients.entrySet()) {
            Session toSession = sessionEntry.getValue();
            // 排除掉自己
            if (!userId.equals(sessionEntry.getKey())) {
                //log.info("服务端给客户端[{}]发送消息{}", toSession.getId(), message);
                log.info("服务端给客户端用户id:[{}]发送消息{}", userId, message);
                toSession.getAsyncRemote().sendText(message);
            }
        }
    }


}

4、前端测试

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

<body>
    <input id="text" type="text" />
    <button onclick="send()">发送</button>
    <button onclick="closeWebSocket()">关闭</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, 更换为自己的地址
    if ('WebSocket' in window) {
        websocket = new WebSocket("ws://localhost:8881/ws/3");  //3为测试用户id
    } 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);
    }

    //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>