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

package com.jiayuan.common.config;

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

/**
 * @Title: WebSocketConfig
 * @Package: com.jiayuan.common.config
 * @Description: websocket配置
 * @Author: xmc
 * @Date: 創(chuàng)建時(shí)間 2024-04-24
 */
@Configuration
public class WebSocketConfig {

    /**
     * 自動(dòng)注冊(cè)使用了@ServerEndpoint注解聲明的Websocket endpoint
     *
     * @return
     */

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

    /**
     * 通信文本消息和二進(jìn)制緩存區(qū)大小
     * 避免對(duì)接 第三方 報(bào)文過(guò)大時(shí)，Websocket 1009 錯(cuò)誤
     *
     * @return
     */

    @Bean
    public ServletServerContainerFactoryBean createWebSocketContainer() {
        ServletServerContainerFactoryBean container = new ServletServerContainerFactoryBean();
        // 在此處設(shè)置bufferSize
        container.setMaxTextMessageBufferSize(10240000);
        container.setMaxBinaryMessageBufferSize(10240000);
        container.setMaxSessionIdleTimeout(15 * 60000L);
        return container;
    }
}
 

package com.jiayuan.common.config;

import cn.hutool.core.collection.CollectionUtil;
import cn.hutool.extra.spring.SpringUtil;
import cn.hutool.json.JSONUtil;
import com.alibaba.fastjson2.JSON;
import com.alibaba.fastjson2.JSONObject;
import com.baomidou.mybatisplus.core.toolkit.StringUtils;
import com.jiayuan.common.redis.RedisCache;
import com.jiayuan.modules.critical.dto.CvRecordExtraDTO;
import com.jiayuan.modules.critical.dto.SyncRecordDTO;
import com.jiayuan.modules.critical.service.CvRecordService;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import javax.annotation.Resource;
import javax.websocket.*;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;
import java.io.IOException;
import java.util.List;
import java.util.concurrent.ConcurrentHashMap;

/**
 * @Title: WebSocketServer
 * @Package: com.jiayuan.common.config
 * @Description: websocket的服務(wù)端
 * @Author: xmc
 * @Date: 創(chuàng)建時(shí)間 2024-04-24
 */
@Component
@Slf4j
@ServerEndpoint("/api/pushMessage/{userId}")
public class WebSocketServer {

    /**
     * 靜態(tài)變量，用來(lái)記錄當(dāng)前在線連接數(shù)。應(yīng)該把它設(shè)計(jì)成線程安全的。
     */
    private static int onlineCount = 0;
    /**
     * concurrent包的線程安全Set，用來(lái)存放每個(gè)客戶(hù)端對(duì)應(yīng)的WebSocket對(duì)象。
     */
    private static ConcurrentHashMap<String, WebSocketServer> webSocketMap = new ConcurrentHashMap<>();
    /**
     * 與某個(gè)客戶(hù)端的連接會(huì)話(huà)，需要通過(guò)它來(lái)給客戶(hù)端發(fā)送數(shù)據(jù)
     */
    private Session session;
    /**
     * 接收userId
     */
    private String userId = "";

    /**
     * 連接建立成
     * 功調(diào)用的方法
     */
    @OnOpen
    public void onOpen(Session session, @PathParam("userId") String userId) {
        this.session = session;
        this.userId = userId;
        if (webSocketMap.containsKey(userId)) {
            webSocketMap.remove(userId);
            //加入set中
            webSocketMap.put(userId, this);
        } else {
            //加入set中
            webSocketMap.put(userId, this);
            //在線數(shù)加1
            addOnlineCount();
        }
        log.info("用戶(hù)連接:" + userId + ",當(dāng)前在線人數(shù)為:" + getOnlineCount());
        sendMessage("連接成功");
    }

    /**
     * 連接關(guān)閉
     * 調(diào)用的方法
     */
    @OnClose
    public void onClose() {
        if (webSocketMap.containsKey(userId)) {
            webSocketMap.remove(userId);
            //從set中刪除
            subOnlineCount();
        }
        log.info("用戶(hù)退出:" + userId + ",當(dāng)前在線人數(shù)為:" + getOnlineCount());
    }

    /**
     * 收到客戶(hù)端消
     * 息后調(diào)用的方法
     *
     * @param message 客戶(hù)端發(fā)送過(guò)來(lái)的消息
     **/
    @OnMessage
    public void onMessage(String message, Session session) {
        log.info("用戶(hù)消息:" + userId + ",報(bào)文:" + message);
        //可以群發(fā)消息
        //消息保存到數(shù)據(jù)庫(kù)、redis
        if (StringUtils.isNotBlank(message)) {
            try {
                //解析發(fā)送的報(bào)文
                JSONObject jsonObject = JSON.parseObject(message);
                //追加發(fā)送人(防止串改)
                jsonObject.put("fromUserId", this.userId);
                String toUserId = jsonObject.getString("toUserId");
                //傳送給對(duì)應(yīng)toUserId用戶(hù)的websocket
                if (StringUtils.isNotBlank(toUserId) && webSocketMap.containsKey(toUserId)) {
                    webSocketMap.get(toUserId).sendMessage(message);
                } else {
                    //否則不在這個(gè)服務(wù)器上，發(fā)送到mysql或者redis
                    log.error("請(qǐng)求的userId:" + toUserId + "不在該服務(wù)器上");
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }


    /**
     * @param session
     * @param error
     */
    @OnError
    public void onError(Session session, Throwable error) {

        log.error("用戶(hù)錯(cuò)誤:" + this.userId + ",原因:" + error.getMessage());
        error.printStackTrace();
    }

    /**
     * 實(shí)現(xiàn)服務(wù)
     * 器主動(dòng)推送
     */
    public void sendMessage(String message) {
        try {
            this.session.getBasicRemote().sendText(message);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * 發(fā)送自定
     * 義消息
     **/
    public static void sendInfo(String message, String userId) {
        log.info("發(fā)送消息到:" + userId + "，報(bào)文:" + message);
        if (StringUtils.isNotBlank(userId) && webSocketMap.containsKey(userId)) {
            webSocketMap.get(userId).sendMessage(message);
        } else {
            log.error("用戶(hù)" + userId + ",不在線！");
        }
    }

    /**
     * 獲得此時(shí)的
     * 在線人數(shù)
     *
     * @return
     */
    public static synchronized int getOnlineCount() {
        return onlineCount;
    }

    /**
     * 在線人
     * 數(shù)加1
     */
    public static synchronized void addOnlineCount() {
        WebSocketServer.onlineCount++;
    }

    /**
     * 在線人
     * 數(shù)減1
     */
    public static synchronized void subOnlineCount() {
        WebSocketServer.onlineCount--;
    }

}
 

WebSocketServer.sendInfo("服務(wù)器主動(dòng)給客戶(hù)端發(fā)送消息test", "zhangsan");

# servlet.context-path 這個(gè)是application.yml中的配置
ws://ip:port//${servlet.context-path}/注解@ServerEndpoint的值

 filterMap.put("/api/pushMessage/*", "anon");