---

前言

   本文章主要记录项目客户端-服务端双向通信解决方案，基于Spring WebSocket架构实现双向数据通信;
以及项目实际应用中的一些问题与解决手段。

一、客户端-服务端双向通信交互图

交互说明：

建立connect并初始化客户端设备、WebSecket等内存信息：
1）服务端WS服务启动
2）客户端向服务端发送接入认证[/ems/robot/access] 主要参数为客户端deviceId;
接入成功后客户端1…N 向WebSocket服务模块【服务端】发送连接请求[ws.connect] ( 客户端 通常sockjs.min.js 来连接）;
双向通道connect连接完成;
WebSocket服务模块内存集合增加WebSecket SessionId信息;
客户端向服务端发送注册[/ems/robot/register]，参数为WebSecket SessionId 和 客户端设备deviceId;
3）服务端通信服务模块建立 【SessionId,设备deviceId】关系

断开disconnect并清除客户端WebSecket、【SessionId,设备deviceId】等内存信息：
1）当客户端主动断开，向服务端-WS发送断开请求[/ems/robot/disconnect] ，通信服务将移除客户端WebSecket、【SessionId,设备deviceId】等内存信息。
2）当非正常情况下断开（如网络问题、假死等），WebSocket服务模块移除客户端WebSecket、【SessionId,设备deviceId】等内存信息。

心跳：
服务端->客户端:
通信服务模块 基于 @Scheduled 组件（@Component），遍历【SessionId,设备deviceId】内存信息，向所有在线的客户端（设备deivce）经过WebSecket（SessionId）通道推送消息;心跳监测-10秒一次，连接4次未收到消息则认为设备断开，集合为：ConcurrentHashMap<String, Integer> heartbeatMonitorMap = new ConcurrentHashMap<>();//key为sessionId，value为未收到消息累计次数

二、项目说明

1.引入包

 <dependency>
     <groupId>org.springframework.boot</groupId>
     <artifactId>spring-boot-starter-websocket</artifactId>
     <exclusions>
         <exclusion>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-tomcat</artifactId>
         </exclusion>
     </exclusions>
 </dependency>
 <dependency>
     <groupId>org.springframework.boot</groupId>
     <artifactId>spring-boot-starter-jetty</artifactId>
 </dependency>

2.项目各模块说明

配置WebSocket,注册handler，将客户端请求转发到端点/merakWs

package com.ems.mgr.websocket.config;
import com.ems.mgr.websocket.handler.SocketHandler;
import com.ems.mgr.websocket.interceptor.WebSocketInterceptor;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.config.annotation.EnableWebSocket;
import org.springframework.web.socket.config.annotation.WebSocketConfigurer;
import org.springframework.web.socket.config.annotation.WebSocketHandlerRegistry;
/**
 * @description: 配置WebSocket,注册handler，将客户端请求转发到端点/merakWs
 */
@Configuration
@EnableWebSocket
public class WebSocketConfig implements WebSocketConfigurer {
    public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
        registry.addHandler(new SocketHandler(), "/merakWs")
                .addInterceptors(new WebSocketInterceptor())
                .setAllowedOrigins("*");
    }
}

自定义WebSocketInterceptor拦截器：

package com.ems.mgr.websocket.interceptor;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.http.server.ServletServerHttpRequest;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.server.HandshakeInterceptor;

import javax.servlet.http.HttpServletRequest;
import java.util.Map;

/**
 * @description: WebSocketInterceptor拦截器，输出通信握手前、握手后标记
 */
public class WebSocketInterceptor implements HandshakeInterceptor {
    private Logger logger = LoggerFactory.getLogger(this.getClass());
    @Override
    public boolean beforeHandshake(ServerHttpRequest request, ServerHttpResponse arg1,
                                   WebSocketHandler arg2, Map<String, Object> arg3) throws Exception {
        // 将ServerHttpRequest转换成request请求相关的类，用来获取request域中的用户信息
        if (request instanceof ServletServerHttpRequest) {
            ServletServerHttpRequest servletRequest = (ServletServerHttpRequest) request;
            HttpServletRequest httpRequest = servletRequest.getServletRequest();
        }
        logger.info("beforeHandshake完成");
        return true;
    }

    @Override
    public void afterHandshake(ServerHttpRequest arg0, ServerHttpResponse arg1, WebSocketHandler arg2, Exception arg3) {
        logger.info("afterHandshake完成");
    }
}

自定义SocketHandler，继承TextWebSocketHandler，处理客户端通道的 消息接收处理handleTextMessage、connect连接成功afterConnectionEstablished、关闭连接afterConnectionClosed、
通道通信异常处理handleTransportError等方法。

package com.ems.mgr.websocket.handler;

import com.ems.mgr.common.utils.AutoDeviceInfoHelperUtil;
import com.ems.mgr.common.utils.DateUtils;
import com.ems.mgr.common.utils.spring.SpringUtils;
import com.ems.mgr.system.domain.AutoDeviceInfo;
import com.ems.mgr.system.service.IAutoDeviceInfoService;
import com.ems.mgr.websocket.commons.JacksonUtil;
import com.ems.mgr.websocket.model.MessageBodyBean;
import com.ems.mgr.websocket.model.WsResponse;
import com.fasterxml.jackson.core.type.TypeReference;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;
import org.springframework.web.socket.CloseStatus;
import org.springframework.web.socket.TextMessage;
import org.springframework.web.socket.WebSocketSession;
import org.springframework.web.socket.handler.ConcurrentWebSocketSessionDecorator;
import org.springframework.web.socket.handler.TextWebSocketHandler;
import java.io.IOException;
import java.util.Date;
/**
 * @description: 自定义SocketHandler，继承TextWebSocketHandler，重载类和实现接口系列方法
 */
@Component
public class SocketHandler extends TextWebSocketHandler {
    private Logger logger = LoggerFactory.getLogger(this.getClass());
    protected WebSocketSessionHandler webSocketSessionHandler = SpringUtils.getBean(WebSocketSessionHandler.class);
    protected IAutoDeviceInfoService deviceInfoService = SpringUtils.getBean(IAutoDeviceInfoService.class);

    @Override
    public void handleTextMessage(WebSocketSession session, TextMessage message) throws Exception {
        logger.info("handleTextMessage from robot...");
        String msg = message.getPayload();
        logger.info("msg Payload= " + msg);
        MessageBodyBean wsParam = JacksonUtil.json2Bean(msg, new TypeReference<MessageBodyBean>() {
        });
        if ("signaling".equals(wsParam.getMessageType()) && "heartbeat".equals(wsParam.getMessageContext())) {
            logger.info("handleTextMessage-Robot心跳监测响应");
            String sessionId = wsParam.getSessionId();
            webSocketSessionHandler.subHeartbeatMonitorMap(sessionId);
        } else {
            logger.info("handleTextMessage-普通响应");
            WsResponse<MessageBodyBean> response = new WsResponse<>();
            MessageBodyBean messageBodyBean = new MessageBodyBean();
            messageBodyBean.setSessionId(session.getId());
            messageBodyBean.setMessageType("signaling");
            messageBodyBean.setMessageContext("response");
            response.setResult(messageBodyBean);
            ConcurrentWebSocketSessionDecorator sessionDecorator = (ConcurrentWebSocketSessionDecorator) webSocketSessionHandler.getSession(session.getId());
            sendMessageToUser(sessionDecorator, new TextMessage(JacksonUtil.bean2Json(response)));
        }
        logger.info("handleTextMessage end...");
    }

    @Override
    public void afterConnectionEstablished(WebSocketSession session) throws Exception {
        logger.info("Connected ... " + session.getId());
        //并发方式
        ConcurrentWebSocketSessionDecorator sessionDecorator = new ConcurrentWebSocketSessionDecorator(session, 10000, 524288);
        //设备已经存在时，需要更新ConcurrentWebSocketSessionDecorator
        webSocketSessionHandler.register(sessionDecorator);
        WsResponse<MessageBodyBean> response = new WsResponse<MessageBodyBean>();
        MessageBodyBean messageBodyBean = new MessageBodyBean();
        messageBodyBean.setSessionId(session.getId());
        messageBodyBean.setMessageType("signaling");
        messageBodyBean.setMessageContext("connect");
        response.setResult(messageBodyBean);
        sendMessageToUser(sessionDecorator, new TextMessage(JacksonUtil.bean2Json(response)));
        //同步方式
//        webSocketSessionHandler.register(session);
//        WsResponse<MessageBodyBean> response = new WsResponse<MessageBodyBean>();
//        MessageBodyBean messageBodyBean = new MessageBodyBean();
//        messageBodyBean.setSessionId(session.getId());
//        messageBodyBean.setMessageType("signaling");
//        messageBodyBean.setMessageContext("connect");
//        response.setResult(messageBodyBean);
//        sendMessageToUser(session, new TextMessage(JacksonUtil.bean2Json(response)));
    }

    @Override
    public void afterConnectionClosed(WebSocketSession session, CloseStatus status) throws Exception {
        logger.warn("afterConnectionClosed->WebSocketSession准备移除:" + session.getId());
//        if (session.isOpen()) {
//            session.close();
//        }
        ConcurrentWebSocketSessionDecorator sessionDecorator = (ConcurrentWebSocketSessionDecorator) webSocketSessionHandler.getSession(session.getId());
        if (sessionDecorator.isOpen()) {
            sessionDecorator.close(status);
        }
        connectionClosedAndUpdate(session.getId());
        logger.info(String.format("afterConnectionClosed->Session %s closed because of %s", session.getId(), status.getReason()));
    }

    @Override
    public void handleTransportError(WebSocketSession session, Throwable throwable) throws Exception {
        logger.warn("handleTransportError->WebSocketSession准备移除:" + session.getId());
        ConcurrentWebSocketSessionDecorator sessionDecorator = (ConcurrentWebSocketSessionDecorator) webSocketSessionHandler.getSession(session.getId());
        if (sessionDecorator.isOpen()) {
            sessionDecorator.close();
        }
        connectionClosedAndUpdate(session.getId());
        logger.error("handleTransportError->error occured at sender " + session.getId(), throwable);
    }

    /**
     * 发送消息给指定的用户:并发方式
     */
    private void sendMessageToUser(ConcurrentWebSocketSessionDecorator user, TextMessage message) {
        try {
            if (user.isOpen()) {
                user.sendMessage(message);
            } else {
                logger.warn("发送消息给指定的用户已经离线");
            }
        } catch (IOException e) {
            logger.error("发送消息给指定的用户出错,err=" + e.getMessage());
        }
    }

    /**
     * 发送消息给指定的用户:同步方式
     */
    private void sendMessageToUserSync(WebSocketSession user, TextMessage message) {
        try {
            if (user.isOpen()) {
                user.sendMessage(message);
            } else {
                logger.warn("发送消息给指定的用户已经离线");
            }
        } catch (IOException e) {
            logger.error("发送消息给指定的用户出错,err=" + e.getMessage());
        }
    }

    private void connectionClosedAndUpdate(String sessionId) {
        try {
            //如果已经注册的设备异常关闭，同时更新设备状态
            String deviceId = webSocketSessionHandler.getDeviceIdBySessionId(sessionId);
            if (!StringUtils.isBlank(deviceId)) {
                AutoDeviceInfo autoDeviceInfo1 = deviceInfoService.selectByPrimaryKey(deviceId);
                if (null != autoDeviceInfo1) {
                    String sysTime = DateUtils.getTime();
                    Date systemDate = DateUtils.parseDate(sysTime);
                    autoDeviceInfo1.setStatus(AutoDeviceInfoHelperUtil.RUNNINGSTATE_OUTLINE);
                    autoDeviceInfo1.setStatusWeight(AutoDeviceInfoHelperUtil.LoadRunningStateWight(AutoDeviceInfoHelperUtil.RUNNINGSTATE_OUTLINE));
                    autoDeviceInfo1.setOnlineTime(systemDate);
                    deviceInfoService.updateByPrimaryKey(autoDeviceInfo1);
                    logger.warn("connectionClosed-[" + autoDeviceInfo1.getStatus() + "->outline]");
                }
                logger.warn("connectionClosedAndUpdate->WebSocketSession关联各Robot设备准备移除[" + sessionId + "," + deviceId + "]");
                webSocketSessionHandler.removeSessionIdAndDevice(sessionId);
            }
            logger.warn("connectionClosedAndUpdate->WebSocketSession准备移除:" + sessionId);
            webSocketSessionHandler.remove(sessionId);
        } catch (Exception e) {
            logger.error("connectionClosedAndUpdate error:" + e.getMessage());
        }
    }
}

WebSocketSessionHandler存储、管理WebSocketSession相关内存集合信息：

package com.ems.mgr.websocket.handler;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Service;
import org.springframework.web.socket.WebSocketSession;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
/**
 * @description: WebSocketSession相关内存集合管理
 */
@Service
public class WebSocketSessionHandler {

    private static final Logger LOGGER = LoggerFactory.getLogger(WebSocketSessionHandler.class);
    //存储各Robot设备的WebSocketSession,如[sessionId,WebSocketSession]
    public final ConcurrentHashMap<String, WebSocketSession> sessionMap = new ConcurrentHashMap<>();
    //sessionId关联各Robot设备id,如[sessionId,id]
    public final ConcurrentHashMap<String, String> sessionIdAndDeviceIdMap = new ConcurrentHashMap<>();
    //心跳监测-1分钟一次，连接4次未收到消息则认为设备断开
    public final ConcurrentHashMap<String, Integer> heartbeatMonitorMap = new ConcurrentHashMap<>();
    public final static Integer maxHeartbeatTime = 4;
    /**
     * @description: WebSocketSession相关操作
     * @param: session WebSocketSession
     */
    public void register(WebSocketSession session) {
        LOGGER.info("WebSocketSession-register:" + session.getId());
        sessionMap.put(session.getId(), session);
    }

    public void remove(String sessionId) {
        sessionMap.remove(sessionId);
        LOGGER.warn("WebSocketSession移除完成:" + sessionId);
    }

    public WebSocketSession getSession(String sessionId) {
        LOGGER.info("WebSocketSession-get:" + sessionId);
        return sessionMap.get(sessionId);
    }

    /**
     * @description: 心跳监测-1分钟一次，连接5次未收到消息则认为设备断开
     * @param: sessionId, id
     */
    public void putHeartbeatMonitorMap(String sessionId) {
        LOGGER.info("心跳监测-put:[" + sessionId + "," + 0 + "]");
        heartbeatMonitorMap.put(sessionId, 0);
    }

    public void addHeartbeatMonitorMap(String sessionId) {
        Integer history = heartbeatMonitorMap.get(sessionId);
        heartbeatMonitorMap.put(sessionId, history + 1);
        LOGGER.info("心跳监测:增加心跳次数[" + sessionId + "," + heartbeatMonitorMap.get(sessionId) + "]");
    }

    public void cleanHeartbeatMonitorMap(String sessionId) {
        heartbeatMonitorMap.remove(sessionId);
        LOGGER.info("心跳监测:清理[" + sessionId + "]");
    }

    public void subHeartbeatMonitorMap(String sessionId) {
        Integer history = heartbeatMonitorMap.get(sessionId);
        if( null != history && 0 < history ){
            heartbeatMonitorMap.put(sessionId, history - 1);
        }
        LOGGER.info("心跳监测:减少心跳次数[" + sessionId + "," + heartbeatMonitorMap.get(sessionId) + "]");
    }

    //判断设备是否达到离线条件：1分钟一次，连接4次未收到消息
    public boolean heartbeatMonitorOutLine(String sessionId) {
        if( maxHeartbeatTime <= heartbeatMonitorMap.get(sessionId) ){
            LOGGER.info("心跳监测-设备达到离线条件:[" + sessionId + "," + maxHeartbeatTime+ "]");
            return true;
        }
        return false;
    }

    public void showSessionIdAndDeviceIdMapTest(ConcurrentHashMap<String, String> sessionIdAndDeviceIdMap){
        LOGGER.info("测试环境展示SessionIdAndDeviceIdMap内存信息");
        Iterator<Map.Entry<String, String>> sessionIdAndDeviceEntriesTest = sessionIdAndDeviceIdMap.entrySet().iterator();
        while (sessionIdAndDeviceEntriesTest.hasNext()) {
            Map.Entry<String, String> entry = sessionIdAndDeviceEntriesTest.next();
            LOGGER.info("SessionIdAndDeviceIdMap内存信息["+entry.getKey()+","+entry.getValue()+"]");
        }
    }

    public WebSocketSession getSessionIdByDeviceId(String deviceId) {
        Iterator<Map.Entry<String, String>> sessionIdAndDeviceEntries = sessionIdAndDeviceIdMap.entrySet().iterator();
        String sessionId = "";
        showSessionIdAndDeviceIdMapTest(sessionIdAndDeviceIdMap);
        while (sessionIdAndDeviceEntries.hasNext()) {
            Map.Entry<String, String> entry = sessionIdAndDeviceEntries.next();
            String deviceId_map = entry.getValue();
            LOGGER.info("getSessionIdByDeviceId list deviceIds:[" +deviceId_map + "]");
            if (deviceId_map.equals(deviceId)) {
                sessionId = entry.getKey();
                LOGGER.info("getSessionIdByDeviceId find:[" + sessionId + "," + deviceId_map + "]");
                break;
            } else {
                continue;
            }
        }
        LOGGER.info("get sessionId-deviceId:[" + sessionId + "," + deviceId + "]");
        if( "".equals(sessionId) ){
            return null;
        }
        else{
            return sessionMap.get(sessionId);
        }
    }

    /**
     * @description: Robot设备相关操作
     * @param: sessionId, deviceId
     */
    public void putSessionIdAndDevice(String sessionId, String deviceId) {
        //判断同一设备多次连接,更新设备WebSocket信息
        WebSocketSession historyWsSession = getSessionIdByDeviceId(deviceId);
        if( null != historyWsSession ){
            LOGGER.warn("删除历史SessionIdAndDevice信息:[" + historyWsSession.getId() + "," + deviceId + "]");
            sessionIdAndDeviceIdMap.remove(historyWsSession.getId());
        }
        LOGGER.info("SessionIdAndDevice put:[" + sessionId + "," + deviceId + "]");
        sessionIdAndDeviceIdMap.put(sessionId, deviceId);
    }

    public void removeSessionIdAndDevice(String sessionId) {
        sessionIdAndDeviceIdMap.remove(sessionId);
        LOGGER.warn("WebSocketSession关联各Robot设备移除完成:" + sessionId);
    }

    public String getDeviceIdBySessionId(String sessionId) {
        String value = sessionIdAndDeviceIdMap.get(sessionId);
        LOGGER.info("SessionIdAndDevice sessionId-deviceId:[" + sessionId + "," + value + "]");
        return value;
    }

    public Map<String, String> getWebSocketSessionIds() {
        Map<String, String> webSocketSessionIdsMap = new HashMap<>();
        Iterator<Map.Entry<String, WebSocketSession>> entries = sessionMap.entrySet().iterator();
        while (entries.hasNext()) {
            Map.Entry<String, WebSocketSession> entry = entries.next();
            webSocketSessionIdsMap.put(entry.getKey(),entry.getValue().getId());
        }
        return webSocketSessionIdsMap;
    }
}

服务端->客户端心跳监测业务类WsSocketController：

package com.ems.mgr.websocket.controller;
import com.ems.mgr.common.utils.AutoDeviceInfoHelperUtil;
import com.ems.mgr.common.utils.DateUtils;
import com.ems.mgr.common.utils.spring.SpringUtils;
import com.ems.mgr.system.domain.AutoDeviceInfo;
import com.ems.mgr.system.service.IAutoDeviceInfoService;
import com.ems.mgr.websocket.commons.JacksonUtil;
import com.ems.mgr.websocket.handler.WebSocketSessionHandler;
import com.ems.mgr.websocket.model.MessageBodyBean;
import com.ems.mgr.websocket.model.WsResponse;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Service;
import org.springframework.web.socket.TextMessage;
import org.springframework.web.socket.WebSocketSession;
import java.io.IOException;
import java.util.Date;
import java.util.Iterator;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

/**
 * @description: 服务端->客户端心跳监测
 * 遍历【SessionId,设备deviceId】内存信息，向所有在线的客户端（设备deivce）经过WebSecket（SessionId）通道推送消息;
 * 心跳监测-10秒一次，连接4次未收到消息则认为设备断开，
 */
@Service
public class WsSocketController {
    private Logger logger = LoggerFactory.getLogger(WsSocketController.class);
    private WebSocketSessionHandler webSocketSessionHandler = SpringUtils.getBean(WebSocketSessionHandler.class);
    private IAutoDeviceInfoService deviceInfoService = SpringUtils.getBean(IAutoDeviceInfoService.class);

    /**
     * @description: Robot心跳监测:定时推送消息（如10秒），监测所有客户端（设备)运行状态，并更新客户端（设备)运行状态值[running运行中,idle空闲]
     */
    @Scheduled(fixedRate = 10000)
    public void heartbeatMonitor() {
        ConcurrentHashMap<String, WebSocketSession> allSessionMap = webSocketSessionHandler.sessionMap;
        ConcurrentHashMap<String, Integer> heartbeatMonitorMapTime = webSocketSessionHandler.heartbeatMonitorMap;
        try{
            if( 0 < allSessionMap.size() ){
                Iterator<Map.Entry<String, WebSocketSession>> entries = allSessionMap.entrySet().iterator();
                while (entries.hasNext()) {
                    Map.Entry<String, WebSocketSession> entry = entries.next();
                    WebSocketSession user = entry.getValue();
                    String sessionId = entry.getKey();
                    WsResponse<MessageBodyBean> response = new WsResponse<MessageBodyBean>();
                    MessageBodyBean messageBodyBean = new MessageBodyBean();
                    messageBodyBean.setSessionId(sessionId);
                    messageBodyBean.setMessageType("signaling");
                    messageBodyBean.setMessageContext("heartbeat");
                    response.setResult(messageBodyBean);
                    String msgJson = JacksonUtil.bean2Json(response);
                    logger.info("WebSocket Service -> Robot心跳监测[定时推送消息时间:"+msgJson+"]");
                    sendMessageToUser(user, new TextMessage(msgJson));
                    //SessionId不存在时，初始化【SessionId，0】
                    Integer heartbeatMap_Value = heartbeatMonitorMapTime.get(sessionId);
                    if( null == heartbeatMap_Value ){
                        logger.info("heartbeatMap init 0");
                        heartbeatMonitorMapTime.put(sessionId,0);
                    }
                    else{
                        //SessionId存在时，每次发送次数+1, 到5次未响应则认为离线
                        if( !webSocketSessionHandler.heartbeatMonitorOutLine(sessionId) ){
                            webSocketSessionHandler.addHeartbeatMonitorMap(sessionId);
                        }
                        else{
                            //设备【sessionId】离线
                            String deviceId = webSocketSessionHandler.getDeviceIdBySessionId(sessionId);
                            AutoDeviceInfo autoDeviceInfo1 = deviceInfoService.selectByPrimaryKey(deviceId);
                            //存在且历史运行状态不为离线OUTLINE时，更新为OUTLINE
                            if( null != autoDeviceInfo1 ){
                                String sysTime = DateUtils.getTime();
                                Date systemDate = DateUtils.parseDate(sysTime);
                                autoDeviceInfo1.setStatus(AutoDeviceInfoHelperUtil.RUNNINGSTATE_OUTLINE);
                                autoDeviceInfo1.setStatusWeight(AutoDeviceInfoHelperUtil.LoadRunningStateWight(AutoDeviceInfoHelperUtil.RUNNINGSTATE_OUTLINE));
                                autoDeviceInfo1.setOnlineTime(systemDate);
                                deviceInfoService.updateByPrimaryKey(autoDeviceInfo1);
                                logger.warn("设备断开-["+autoDeviceInfo1.getStatus()+"->outline]");
                            }
                            logger.warn("Robot心跳监测-设备离线,移除:" + sessionId);
                            webSocketSessionHandler.remove(sessionId);
                            logger.warn("Robot心跳监测-设备离线,关联设备准备移除[" + sessionId+","+deviceId +"]");
                            webSocketSessionHandler.removeSessionIdAndDevice(sessionId);
                            webSocketSessionHandler.cleanHeartbeatMonitorMap(sessionId);
                        }
                    }
                    Thread.sleep(200);
                }
            }
            else{
                logger.warn("WebSocket Service -> Robot心跳监测[无连接设备，请先接入并注册设备]");
            }
        }catch (Exception e){
            logger.warn("WebSocket Service -> Robot心跳监测异常,msg="+e.getMessage());
        }
    }

    /**
     * 发送消息给指定的用户
     */
    public void sendMessageToUser(WebSocketSession user, TextMessage message) {
        try {
            // 在线就发送
            if (user.isOpen()) {
                user.sendMessage(message);
                logger.info("Message {"+user.getId()+"} send success");
            }
            else{
                logger.warn("发送消息给指定的用户已经离线");
            }
        } catch (IOException e) {
            logger.error("发送消息给指定的用户出错", e);
        }
    }

    //1:保证websocket同设备在线状态不一致的问题处理
    public void syncDeviceWebsocket(String sessionId){
        String deviceId = webSocketSessionHandler.getDeviceIdBySessionId(sessionId);
        if( null != deviceId ){
            AutoDeviceInfo autoDeviceInfo1 = deviceInfoService.selectByPrimaryKey(deviceId);
            if( null != autoDeviceInfo1 && AutoDeviceInfoHelperUtil.RUNNINGSTATE_OUTLINE.equals(autoDeviceInfo1.getStatus()) ){
                String sysTime = DateUtils.getTime();
                Date systemDate = DateUtils.parseDate(sysTime);
                autoDeviceInfo1.setStatus(AutoDeviceInfoHelperUtil.RUNNINGSTATE_IDLE);
                autoDeviceInfo1.setStatusWeight(AutoDeviceInfoHelperUtil.LoadRunningStateWight(AutoDeviceInfoHelperUtil.RUNNINGSTATE_IDLE));
                autoDeviceInfo1.setOnlineTime(systemDate);
                deviceInfoService.updateByPrimaryKey(autoDeviceInfo1);
                logger.warn("保证websocket同设备在线状态[outline->idle]一致");
            }
        }
    }
}

设备信息通信管理类DeviceInfoController，设备接入、注册、断开（客户端主动）、接收消息：

package com.ems.mgr.web.controller.websocket;
import com.ems.mgr.common.core.controller.BaseController;
import com.ems.mgr.common.core.domain.AjaxResult;
import com.ems.mgr.common.utils.AutoDeviceInfoHelperUtil;
import com.ems.mgr.common.utils.DateUtils;
import com.ems.mgr.common.utils.sign.Md5SaltUtilsHelper;
import com.ems.mgr.system.domain.AutoAppConfig;
import com.ems.mgr.system.domain.AutoDeviceInfo;
import com.ems.mgr.system.service.IAutoAppConfigService;
import com.ems.mgr.system.service.IAutoDeviceInfoService;
import com.ems.mgr.websocket.commons.JacksonUtil;
import com.ems.mgr.websocket.handler.WebSocketSessionHandler;
import com.ems.mgr.websocket.model.MessageBodyBean;
import com.ems.mgr.websocket.model.WsResponse;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.socket.TextMessage;
import org.springframework.web.socket.WebSocketSession;
import java.io.IOException;
import java.util.Date;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.stream.Collectors;

/**
 * 设备信息通信管理类：设备接入、注册、断开（客户端主动）、接收消息
 */
@RestController
@RequestMapping("/ems/robot")
public class DeviceInfoController extends BaseController {
    public static final Logger log = LoggerFactory.getLogger(DeviceInfoController.class);
    @Autowired
    private IAutoDeviceInfoService deviceInfoService;
    @Autowired
    private IAutoAppConfigService autoAppConfigService;
    @Autowired
    private WebSocketSessionHandler webSocketSessionHandler;

    /**
     * 接入接口
     */
    @PostMapping(value = "/access")
    public AjaxResult access(@RequestBody AutoAppConfig autoAppConfig) {
        log.info("设备开始接入");
        String serverHost = autoAppConfig.getServerHost();
        String appId = autoAppConfig.getAppId();
        List<AutoAppConfig> autoAppConfigsRecs = autoAppConfigService.selectAll();
        if( 0 == autoAppConfigsRecs.size() ){
            return AjaxResult.error("应用设备未登记接入信息!");
        }
        if( StringUtils.isBlank(serverHost)){
            return AjaxResult.error("应用设备接入服务器地址不正确!");
        }
        if( StringUtils.isBlank(appId)){
            return AjaxResult.error("应用设备接入设备码不正确!");
        }
        List<AutoAppConfig> findAutoAppConfigs = autoAppConfigsRecs.stream().filter(u ->(u.getAppId().equals(appId) && u.getServerHost().equals(serverHost)) ).collect(Collectors.toList());
        if( 0 == findAutoAppConfigs.size() ){
            log.error("接入应用配置信息未配置设备码appId["+autoAppConfig.getAppId()+"]不正确，请检查auto_app_config表!");
            return AjaxResult.error("应用设备接入信息不正确!");
        }
        AutoAppConfig findAutoAppConfig = findAutoAppConfigs.get(0);
        boolean matchResp = Md5SaltUtilsHelper.matchMd5(appId,findAutoAppConfig.getAppTimestamp().getTime(),findAutoAppConfig.getAuthCode(),findAutoAppConfig.getAppSecret(),autoAppConfig.getAppSign());
        return matchResp ? AjaxResult.success() : AjaxResult.error("应用设备接入签名不匹配!");
    }

    /**
     * 连接成功后，注册/api/robot/register
     */
    @PostMapping(value = "/register")
    public AjaxResult register(@RequestBody AutoDeviceInfo autoDeviceInfo) {
        log.info("设备连接成功后开始注册");
        String msg = "";
        String deviceId = autoDeviceInfo.getId();
        String sessionId = autoDeviceInfo.getSessionId();
        try{
            if( null != webSocketSessionHandler.getSession(sessionId) ){
                //在线
                AutoDeviceInfo autoDeviceInfo1 = deviceInfoService.selectByPrimaryKey(autoDeviceInfo.getId());
                if( null == autoDeviceInfo1 ){
                    msg = "设备注册失败,设备["+autoDeviceInfo.getId()+"]不存在!";
                    log.error(msg);
                    return AjaxResult.error(msg);
                }
                else{
                    String sysTime = DateUtils.getTime();
                    Date systemDate = DateUtils.parseDate(sysTime);
                    autoDeviceInfo1.setMachineIp(autoDeviceInfo.getMachineIp());
                    autoDeviceInfo1.setStatus(AutoDeviceInfoHelperUtil.RUNNINGSTATE_IDLE);
                    autoDeviceInfo1.setStatusWeight(AutoDeviceInfoHelperUtil.LoadRunningStateWight(AutoDeviceInfoHelperUtil.RUNNINGSTATE_IDLE));
                    autoDeviceInfo1.setOnlineTime(systemDate);
                    autoDeviceInfo1.setVers(autoDeviceInfo.getVers());
                    autoDeviceInfo1.setPythonVers(autoDeviceInfo.getPythonVers());
                    deviceInfoService.updateByPrimaryKey(autoDeviceInfo1);
                    msg = "设备注册成功,设备["+autoDeviceInfo.getId()+"],sessionId["+sessionId+"]";
                    log.info(msg);
                    webSocketSessionHandler.putSessionIdAndDevice(sessionId,deviceId);
                    return AjaxResult.success(msg);
                }
            }
            String msg2 = "设备注册失败，设备已经断开,设备["+autoDeviceInfo.getId()+"],sessionId["+sessionId+"]";
            log.info(msg2);
            return AjaxResult.error(msg2);
        }catch (Exception e){
            msg = "设备注册异常，msg["+e.getMessage()+"],设备["+autoDeviceInfo.getId()+"],sessionId["+sessionId+"]";
            log.error(msg);
            return AjaxResult.error(msg);
        }
    }

    /**
     * 断开/api/robot/disconnect：先断开，然后再接收断开服务接口/disconnect
     */
    @PostMapping(value = "/disconnect")
    public AjaxResult disconnect(@RequestBody AutoDeviceInfo autoDeviceInfo) {
        String msg = "";
        String sessionId = autoDeviceInfo.getSessionId();
        String deviceId = autoDeviceInfo.getId();
        try{
            msg = "接收执行器断开服务请求,Socket关联信息["+sessionId+","+deviceId+"]断开!";
            log.warn(msg);
            AutoDeviceInfo autoDeviceInfo1 = deviceInfoService.selectByPrimaryKey(deviceId);
            //存在且历史运行状态不为离线OUTLINE时，更新为OUTLINE
            if( null != autoDeviceInfo1 ){
                String sysTime = DateUtils.getTime();
                Date systemDate = DateUtils.parseDate(sysTime);
                autoDeviceInfo1.setStatus(AutoDeviceInfoHelperUtil.RUNNINGSTATE_OUTLINE);
                autoDeviceInfo1.setStatusWeight(AutoDeviceInfoHelperUtil.LoadRunningStateWight(AutoDeviceInfoHelperUtil.RUNNINGSTATE_OUTLINE));
                autoDeviceInfo1.setOnlineTime(systemDate);
                log.warn("设备断开-["+autoDeviceInfo1.getStatus()+"->outline]");
                deviceInfoService.updateByPrimaryKey(autoDeviceInfo1);
            }
            logger.warn("Robot主动断开服务接口disconnect->WebSocketSession准备移除:" + sessionId);
            webSocketSessionHandler.remove(sessionId);
            logger.warn("Robot主动断开服务接口disconnect->WebSocketSession关联各Robot设备准备移除[" + sessionId+","+deviceId +"]");
            webSocketSessionHandler.removeSessionIdAndDevice(sessionId);
            return AjaxResult.success();
        }catch (Exception e){
            msg = "设备断开异常，msg["+e.getMessage()+"],设备["+autoDeviceInfo.getId()+"],sessionId["+sessionId+"]";
            log.error(msg);
            return AjaxResult.error(msg);
        }
    }

    /**
     * 接收调度中心调用机器人消息
     */
    @PostMapping(value = "/handleRobotMessage/{deviceId}")
    public AjaxResult handleRobotMessage(@PathVariable String deviceId,
                                         @RequestBody MessageBodyBean messageBodyBean) {
        try{
            log.info("设备接收调度中心调用机器人消息");
            if( !StringUtils.isBlank(deviceId) ){
                AutoDeviceInfo autoDeviceInfo1 = deviceInfoService.selectByPrimaryKey(deviceId);
                if( "stop".equals(messageBodyBean.getBussinessType()) ){
                    //stop:停止
                    WebSocketSession session = webSocketSessionHandler.getSessionIdByDeviceId(deviceId);
                    if( null != session ){
                        WsResponse<MessageBodyBean> response = new WsResponse<MessageBodyBean>();
                        messageBodyBean.setSessionId(session.getId());
                        response.setResult(messageBodyBean);
                        sendMessageToUser(session, new TextMessage(JacksonUtil.bean2Json(response)));
                        log.info("接收调度中心终止业务消息已完成,设备["+deviceId+"]");
                        return AjaxResult.success();
                    }
                    else{
                        String msg = "接收调度中心终止业务失败,机器人已接入但未注册使用,设备["+deviceId+"]";
                        log.info(msg);
                        return AjaxResult.error(msg);
                    }
                }
                else{
                    //存在且运行状态不为离线OUTLINE时，更新为OUTLINE
                    if( null != autoDeviceInfo1 && AutoDeviceInfoHelperUtil.RUNNINGSTATE_IDLE.equals(autoDeviceInfo1.getStatus())){
                        log.info("接收调度中心调用机器人消息,设备["+deviceId+"]");
                        WebSocketSession session = webSocketSessionHandler.getSessionIdByDeviceId(deviceId);
                        if( null != session ){
                            WsResponse<MessageBodyBean> response = new WsResponse<MessageBodyBean>();
                            messageBodyBean.setSessionId(session.getId());
                            response.setResult(messageBodyBean);
                            sendMessageToUser(session, new TextMessage(JacksonUtil.bean2Json(response)));
                            String sysTime = DateUtils.getTime();
                            Date systemDate = DateUtils.parseDate(sysTime);
                            autoDeviceInfo1.setStatus(AutoDeviceInfoHelperUtil.RUNNINGSTATE_RUNNING);
                            autoDeviceInfo1.setStatusWeight(AutoDeviceInfoHelperUtil.LoadRunningStateWight(AutoDeviceInfoHelperUtil.RUNNINGSTATE_RUNNING));
                            autoDeviceInfo1.setOnlineTime(systemDate);
                            deviceInfoService.updateByPrimaryKey(autoDeviceInfo1);
                            log.info("接收调度中心调用机器人消息已完成,设备["+deviceId+"]");
                            return AjaxResult.success();
                        }
                        else{
                            String msg = "接收调度中心调用空闲机器人已接入但未注册使用,设备["+deviceId+"]";
                            log.info(msg);
                            return AjaxResult.error(msg);
                        }
                    }
                    else{
                        String msg = "接收调度中心调用无空闲机器人,设备["+deviceId+"]";
                        log.info(msg);
                        return AjaxResult.error(msg);
                    }
                }
            }
            else{
                String msg = "接收调度中心调用机器人消息异常,设备["+deviceId+"]";
                log.info(msg);
                return AjaxResult.error(msg);
            }
        }catch (Exception e){
            String msg = "接收调度中心调用机器人消息异常，msg["+e.getMessage()+"],设备["+deviceId+"]";
            log.info(msg);
            return AjaxResult.error(msg);
        }
    }

    /**
     * Robot执行完py流程后，更新Robot运行状态和运行状态排序权重
     */
    @PutMapping(value = "/{deviceId}")
    public AjaxResult updateDeviceStatus(@PathVariable String deviceId,
                                         @RequestBody String status) {
        try{
            log.info("Robot执行完py流程更新Robot运行状态,设备["+deviceId+"]");
            AutoDeviceInfo autoDeviceInfo1 = deviceInfoService.selectByPrimaryKey(deviceId);
            //存在且历史运行状态不为离线OUTLINE时，更新为OUTLINE
            if( null != autoDeviceInfo1 ){
                String sysTime = DateUtils.getTime();
                Date systemDate = DateUtils.parseDate(sysTime);
                autoDeviceInfo1.setStatus(AutoDeviceInfoHelperUtil.RUNNINGSTATE_IDLE);
                autoDeviceInfo1.setStatusWeight(AutoDeviceInfoHelperUtil.LoadRunningStateWight(AutoDeviceInfoHelperUtil.RUNNINGSTATE_IDLE));
                autoDeviceInfo1.setOnlineTime(systemDate);
                deviceInfoService.updateByPrimaryKey(autoDeviceInfo1);
                log.info("更新Robot运行状态完成,设备["+deviceId+"]");
            }
            return AjaxResult.success();
        }catch (Exception e){
            String msg = "设备状态更新接口异常，msg["+e.getMessage()+"],设备["+deviceId+"]";
            log.error(msg);
            return AjaxResult.error(msg);
        }
    }

    /**
     * 设备信息接口说明
     * 参数   appId:设备主键id
     * 返回结果 AjaxResult
     */
    @GetMapping(value = "/devicevideopolicy")
    public AjaxResult deviceDetail(@RequestParam(name = "appId") String appId) {
        return AjaxResult.success(deviceInfoService.selectByPrimaryKey(appId));
    }

    /**
     * 发送消息给指定的用户
     */
    public void sendMessageToUser(WebSocketSession user, TextMessage message) {
        try {
            String msg;
            if (user.isOpen()) {
                msg = "发送消息给指定的在线用户，WebSocketSessionId["+user.getId()+"]";
                logger.info(msg);
                user.sendMessage(message);
            }
            else{
                msg = "用户已经离线，WebSocketSessionId["+user.getId()+"]";
                logger.error(msg);
            }
        } catch (IOException e) {
            logger.error("发送消息给指定的用户出错"+e.getMessage());
        }
    }

    @GetMapping("/loadWebSocketSessions")
    public AjaxResult loadWebSocketSessions(){
        Map<String, String> msg = webSocketSessionHandler.getWebSocketSessionIds();
        return AjaxResult.success(msg);
    }

    @GetMapping("/loadWebSessionIdAndDeviceId")
    public AjaxResult loadWebSessionIdAndDeviceId(){
        ConcurrentHashMap<String,String> msg = webSocketSessionHandler.sessionIdAndDeviceIdMap;
        return AjaxResult.success(msg);
    }
}

spring工具类SpringUtils，非spring管理环境中获取bean：

package com.ems.mgr.common.utils.spring;

import com.ems.mgr.common.utils.StringUtils;
import org.springframework.aop.framework.AopContext;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.NoSuchBeanDefinitionException;
import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;

@Component
public final class SpringUtils implements BeanFactoryPostProcessor, ApplicationContextAware 
{
    /** Spring应用上下文环境 */
    private static ConfigurableListableBeanFactory beanFactory;

    private static ApplicationContext applicationContext;

    @Override
    public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException 
    {
        SpringUtils.beanFactory = beanFactory;
    }

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException 
    {
        SpringUtils.applicationContext = applicationContext;
    }

    /**
     * 获取对象
     *
     * @param name
     * @return Object 一个以所给名字注册的bean的实例
     * @throws org.springframework.beans.BeansException
     *
     */
    @SuppressWarnings("unchecked")
    public static <T> T getBean(String name) throws BeansException
    {
        return (T) beanFactory.getBean(name);
    }

    /**
     * 获取类型为requiredType的对象
     *
     * @param clz
     * @return
     * @throws org.springframework.beans.BeansException
     *
     */
    public static <T> T getBean(Class<T> clz) throws BeansException
    {
        T result = (T) beanFactory.getBean(clz);
        return result;
    }

    /**
     * 如果BeanFactory包含一个与所给名称匹配的bean定义，则返回true
     *
     * @param name
     * @return boolean
     */
    public static boolean containsBean(String name)
    {
        return beanFactory.containsBean(name);
    }

    /**
     * 判断以给定名字注册的bean定义是一个singleton还是一个prototype。 如果与给定名字相应的bean定义没有被找到，将会抛出一个异常（NoSuchBeanDefinitionException）
     *
     * @param name
     * @return boolean
     * @throws org.springframework.beans.factory.NoSuchBeanDefinitionException
     *
     */
    public static boolean isSingleton(String name) throws NoSuchBeanDefinitionException
    {
        return beanFactory.isSingleton(name);
    }

    /**
     * @param name
     * @return Class 注册对象的类型
     * @throws org.springframework.beans.factory.NoSuchBeanDefinitionException
     *
     */
    public static Class<?> getType(String name) throws NoSuchBeanDefinitionException
    {
        return beanFactory.getType(name);
    }

    /**
     * 如果给定的bean名字在bean定义中有别名，则返回这些别名
     *
     * @param name
     * @return
     * @throws org.springframework.beans.factory.NoSuchBeanDefinitionException
     *
     */
    public static String[] getAliases(String name) throws NoSuchBeanDefinitionException
    {
        return beanFactory.getAliases(name);
    }

    /**
     * 获取aop代理对象
     * 
     * @param invoker
     * @return
     */
    @SuppressWarnings("unchecked")
    public static <T> T getAopProxy(T invoker)
    {
        return (T) AopContext.currentProxy();
    }

    /**
     * 获取当前的环境配置，无配置返回null
     *
     * @return 当前的环境配置
     */
    public static String[] getActiveProfiles()
    {
        return applicationContext.getEnvironment().getActiveProfiles();
    }

    /**
     * 获取当前的环境配置，当有多个环境配置时，只获取第一个
     *
     * @return 当前的环境配置
     */
    public static String getActiveProfile()
    {
        final String[] activeProfiles = getActiveProfiles();
        return StringUtils.isNotEmpty(activeProfiles) ? activeProfiles[0] : null;
    }
}

客户端（设备）常量类AutoDeviceInfoHelperUtil：

package com.ems.mgr.common.utils;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.HashMap;
import java.util.Map;
public class AutoDeviceInfoHelperUtil {
    public static final Logger log = LoggerFactory.getLogger(AutoDeviceInfoHelperUtil.class);

    /*
    运行状态:
    running运行中
    idle空闲
    outline断开连接[未连接](默认),
    remove_cooling移除冷却
     */
    public final static String RUNNINGSTATE_RUNNING = "running";
    public final static String RUNNINGSTATE_IDLE = "idle";
    public final static String RUNNINGSTATE_OUTLINE = "outline";
    public final static String RUNNINGSTATE_REMOVE_COOLING = "remove_cooling";

    // 某类中定义的获取运行状态-运行状态排序权重的方法以及EnumMap的声明
    private static Map<String, Integer> runningStateWight = new HashMap<>();

    /**
     * @description:运行状态-运行状态排序权重映射
        running | idle :70；
        outline:50
        remove_cooling:30
     */
    static {
        runningStateWight.put(RUNNINGSTATE_RUNNING, 70);
        runningStateWight.put(RUNNINGSTATE_IDLE, 70);
        runningStateWight.put(RUNNINGSTATE_OUTLINE, 50);
        runningStateWight.put(RUNNINGSTATE_REMOVE_COOLING, 30);
    }

    //根据不同的运行状态类型，返回对应的运行状态排序权重
    public static Integer LoadRunningStateWight(String runningState) {
        Integer stateWight = -1;
        if( null != runningState ) {
            stateWight = runningStateWight.get(runningState);
        }
        return stateWight;
    }

}

问题

1.当接入、连接的客户端（设备）量过大（如50台时），服务端心跳监测向客户端推送消息时，WebSocketSession.sendMessage(message)方法出现同步排队，导致客户端接收消息出现堵塞与延迟。
排查：跟踪Spring WebSocket源代码AbstractWebSocketSession类sendMessage(WebSocketMessage<?> message) -> StandardWebSocketSession 类sendMessage
-> WsRemoteEndpointBasic类 sendText(String fragment, boolean isLast) -> WsRemoteEndpointImplBase类 sendPartialString(String fragment, boolean isLast) 方法在消息发送（sendMessageBlock）前，同步synchronized判断通道状态State ：
public synchronized void textPartialStart() {
checkState(State.OPEN, State.TEXT_PARTIAL_READY);
state = State.TEXT_PARTIAL_WRITING;
}
解决方案：SocketHandler类在对端建立连接后afterConnectionEstablished(WebSocketSession session)，将单线程WebSocketSession session 修改为并发方式ConcurrentWebSocketSessionDecorator，即：
ConcurrentWebSocketSessionDecorator sessionDecorator = new ConcurrentWebSocketSessionDecorator(session, 10000, 524288)

参考

demo资源下载地址
demo参考 boot-websocket