javaWEB项目中webSocket的简单应用

客官°小女子只卖身不卖艺 2022-06-09 09:22 219阅读 0赞

webSocket握手协议  
客户端到服务端：  
GET /demo HTTP/1.1  
Host: example.com  
Connection: Upgrade  
Sec-WebSocket-Key2: 12998 5 Y3 1 .P00  
Upgrade: WebSocket  
Sec-WebSocket-Key1: 4@1 46546xW%0l 1 5  
Origin: [http://example.com][http_example.com]  
\[8-byte security key\]

服务端到客户端：  
HTTP/1.1 101 WebSocket Protocol Handshake  
Upgrade: WebSocket  
Connection: Upgrade  
WebSocket-Origin: [http://example.com][http_example.com]  
WebSocket-Location: ws://example.com/demo  
\[16-byte hash response\]

1.添加maven依赖

tomcat版本要7.0.65及以上,不然不支持webSocket
    
    <spring.version>4.3.9.RELEASE</spring.version>
        <dependency>
            <groupId>net.sf.json-lib</groupId>
            <artifactId>json-lib</artifactId>
            <version>2.4</version>
            <classifier>jdk15</classifier>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>2.8.5</version>
        </dependency>
          <dependency>  
        <groupId>com.fasterxml.jackson.core</groupId>  
        <artifactId>jackson-databind</artifactId>  
        <version>2.8.5</version>  
    </dependency>
    
    <dependency>
       <groupId>javax.websocket</groupId>
       <artifactId>javax.websocket-api</artifactId>
       <version>1.1</version>
       <scope>provided</scope>
    </dependency>
    
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-websocket</artifactId>
        <version>${spring.version}</version>
    </dependency>

2.Spring-mvc.xml文件中添加

<bean id="mappingJacksonHttpMessageConverter" class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
            <property name="supportedMediaTypes">
                <list>
                    <value>text/html;charset=UTF-8</value>
                </list>
            </property>
        </bean>

3.前端代码 包含心跳重连

添加webSocket的js引用
    <script src="${pageContext.request.contextPath}/js/sockjs-0.3.min.js"></script>
     /*Websocket*/
            var websocket;
            var userId = $('#userId').val();
            var storeId = $('#storeId').val();
            var host = window.location.host;
            if(storeId!=0){
                    if('WebSocket' in window) {
                        console.log("此浏览器支持websocket");
                        reconnect(userId,storeId);
                    } else if('MozWebSocket' in window) {
                        alert("此浏览器只支持MozWebSocket");
                    } else {    
                        alert("此浏览器只支持SockJS");
                    }
                    //websocket连接打开
                    websocket.onopen = function(evnt) { 
                          heartCheck.start();
                        $("#socketMsg").html("链接服务器成功!")
                    };
                    //接收到服务器消息时调用方法
                    websocket.onmessage = function(evnt) { 
                         heartCheck.reset();
                         var  resultMsg = JSON.parse(evnt.data)
                        //调用播放语音的方法
                        var ele= document.getElementById("eleme");
                        var meituan = document.getElementById("meituan");
                        if(resultMsg.message.indexOf("饿了么")!=-1){
                            ele.play();
                        }else if(evnt.data.indexOf("美团")!=-1){
                            meituan.play();
                        }
                        //调用打印方法
                            var orderId = resultMsg.orderId;
                            if(orderId!='' && orderId!=null  &&　orderId != undefined){
                                print(orderId);
                            }
    
                    };
                    websocket.onerror = function(evnt) { 
                        reconnect(userId,storeId);
                        $('#socketMsg').html("与服务器连接异常!");
                    };
                    websocket.onclose = function(evnt) { 
                        reconnect(userId,storeId);
                        $("#socketMsg").html("与服务器断开了链接!")
                    }
            }
                    //心跳重连
                var heartCheck = {
                    timeout: 30000,//60ms
                    timeoutObj: null,
                    serverTimeoutObj: null,
                    reset: function(){ 
                        clearTimeout(this.timeoutObj);
                        clearTimeout(this.serverTimeoutObj);
                　　　　 this.start();
                    },
                    start: function(){ 
                        var self = this;
                        this.timeoutObj = setTimeout(function(){ 
                            websocket.send("HeartBeat");
                            self.serverTimeoutObj = setTimeout(function(){ 
                                //如果onclose会执行reconnect，我们执行ws.close()就行了.如果直接执行reconnect 会触发onclose导致重连两次
                                websocket.close();
                            }, self.timeout)
                        }, this.timeout)
                    },
            }
                    //重连方法
                    function reconnect(userId,storeId){ 
                     websocket = new WebSocket("ws://"+host+"/koms/websocket/remindOrder/"+userId+"/"+storeId);
                    }

4.服务端代码  
其中包含一些业务代码,需要做到订单自动打印,打印的控制是放在HttpSession里面，当时做的时候碰到一个问题,当一个用户在同一个浏览器里面打开多个窗口的时候，消息会重复发多次. 就会重复打印。  
登录一个页面之后,当前页面不关闭,直接复制本页面,这样我的服务端的Set集合里面对同一个用户保存了多个webSocket的session，这样我在服务端给客户端发信息的时候，同一个用户在同一个浏览器就发了多次。  
后来的解决方案是,将webSocket的session保存到HttpSession中，每一个HttpSession发送一条信息,然后跳出，这样就不会存在同一个HTTPSession发多个消息了。同一个用户登录登录不同的浏览器,这样httpSession就不一样,我们业务里面允许就没有做处理

在Websocket中获取httpsession

import javax.servlet.http.HttpSession;
    import javax.websocket.HandshakeResponse;
    import javax.websocket.server.HandshakeRequest;
    import javax.websocket.server.ServerEndpointConfig;
    import javax.websocket.server.ServerEndpointConfig.Configurator;
    /* * 获取HttpSession * */
    
    public class GetHttpSessionConfigurator extends Configurator { 
    
        @Override
        public void modifyHandshake(ServerEndpointConfig sec,
                HandshakeRequest request, HandshakeResponse response) {
            // TODO Auto-generated method stub
            HttpSession httpSession=(HttpSession) request.getHttpSession();
            sec.getUserProperties().put(HttpSession.class.getName(),httpSession);
        }
    
    }

import java.io.IOException;
    import java.util.HashMap;
    import java.util.HashSet;
    import java.util.Map;
    import java.util.Set;
    
    import javax.servlet.http.HttpSession;
    import javax.websocket.EndpointConfig;
    import javax.websocket.OnClose;
    import javax.websocket.OnError;
    import javax.websocket.OnMessage;
    import javax.websocket.OnOpen;
    import javax.websocket.Session;
    import javax.websocket.server.PathParam;
    import javax.websocket.server.ServerEndpoint;
    
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    import org.springframework.stereotype.Component;
    
    import com.cn.framework.constant.SessionListener;
    
    @Component
    @ServerEndpoint(value="/websocket/remindOrder/{userId}/{storeId}",configurator=GetHttpSessionConfigurator.class)
    public class OrderRemind { 
        //日志记录
        private Logger logger = LoggerFactory.getLogger(OrderRemind.class);
    
        //记录每个用户下多个终端的连接
        private static Map<Long, Set<OrderRemind>> userSocket = new HashMap<>();
    
        //需要session来对用户发送数据, 获取连接特征userId
        private Session session;
        private  Long userId;
        private int storeId;
    
        //httpsession
        public  static HttpSession httpSession = null;
        /** * @Title: onOpen * @Description: websocekt连接建立时的操作 * @param @param userId 用户id * @param @param session websocket连接的session属性 * @param @throws IOException */
        @OnOpen
        public void onOpen(@PathParam("userId") Long userId,@PathParam("storeId") int storeId,Session session,EndpointConfig config) throws IOException{
            this.session = session;
            this.userId = userId;
            this.storeId = storeId;
    
    
            //将webSocket的对象放到HttpSession集合中
            httpSession= (HttpSession) config.getUserProperties().get(HttpSession.class.getName());
            Set<OrderRemind>  webSocketSessions = (Set) httpSession.getAttribute("webSocketObject");
            if(webSocketSessions!=null){
                webSocketSessions.add(this);
            }else{
                webSocketSessions  = new HashSet<>();
                webSocketSessions.add(this);
            }
            httpSession.setAttribute("webSocketObject", webSocketSessions);
    
            //根据该用户当前是否已经在别的终端登录进行添加操作
            if (userSocket.containsKey(this.userId)) {
                Set<OrderRemind> set = userSocket.get(this.userId);
                System.out.println(set.size());
                logger.error("当前用户id:{},门店:{},weSocketSession:{},已有其他终端登录",this.userId,this.storeId,this.session.hashCode());
                userSocket.get(this.userId).add(this); //增加该用户set中的连接实例
            }else {
                   logger.error("当前用户id:{},门店:{},weSocketSession:{},第一个终端登录",this.userId,this.storeId,this.session.hashCode());
                Set<OrderRemind> addUserSet = new HashSet<>();
                addUserSet.add(this);
                userSocket.put(this.userId, addUserSet);
            }
            logger.error("用户{}登录的终端个数是为{}",userId,userSocket.get(this.userId).size());
            logger.error("当前在线用户数为：{},所有终端个数为：{}",userSocket.size(),SessionListener.sessions.size());
        }
    
        /** * @Title: onClose * @Description: 连接关闭的操作 */
        @OnClose
        public void onClose(){
            //连接关闭的时候 httpsession中移除webSocket对象
            Set<OrderRemind>  webSocketSessions = (Set) httpSession.getAttribute("webSocketObject");
            webSocketSessions.remove(this);
            httpSession.setAttribute("webSocketObject",webSocketSessions);
    
            //移除当前用户终端登录的websocket信息,如果该用户的所有终端都下线了，则删除该用户的记录
            if (userSocket.get(this.userId).size() == 0) {
                userSocket.remove(this.userId);
            }else{
                userSocket.get(this.userId).remove(this);
            }
            logger.error("用户{}登录的终端个数是为{}",this.userId,userSocket.get(this.userId).size());
            logger.error("当前在线用户数为：{},所有终端个数为：{}",userSocket.size(),SessionListener.sessions.size());
        }
    
        /** * @Title: onMessage * @Description: 收到消息后的操作 * @param @param message 收到的消息 * @param @param session 该连接的session属性 */
        @OnMessage
        public void onMessage(String message, Session session) {    
            logger.error("收到来自用户id为：{}的消息：{}",this.userId,message);
            if(session ==null)  logger.debug("session null");
            //心跳重连机制
            try {
                session.getBasicRemote().sendText("{\"message\":\"连接正常!\"}");
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    
        /** * @Title: onError * @Description: 连接发生错误时候的操作 * @param @param session 该连接的session * @param @param error 发生的错误 */
        @OnError
        public void onError(Session session, Throwable error){
            logger.error("用户id为：{}的连接发送错误",this.userId);
            error.printStackTrace();
        }
    
        /** * @Title: sendMessageToUser * @Description: 发送消息给用户下的所有终端 * @param @param userId 用户id * @param @param message 发送的消息 * @param @return 发送成功返回true，反则返回false */
          public Boolean sendMessageToUser(Map<String,Object> remindMessage){
            //订单门店
            int storeId = (Integer)remindMessage.get("store_id");
            //订单渠道
            int channelId = (Integer)remindMessage.get("channel_id");
            //品牌
            int brandId = (Integer)remindMessage.get("brand_id");
            //订单号
            Integer orderId =  (Integer)remindMessage.get("order_id");
            logger.error("sendMessageToUser:{ storeId:"+storeId+" ---- channelId"+channelId+" ---- brandId"+brandId+"}");
             String   message = "";
            if(channelId==1){
                message = "{\"message\":\"您有新的饿了么订单,请及时处理\",\"orderId\":\""+orderId+"\"}";
            }else if(channelId ==2){
                message = "{\"message\":\"您有新的美团外卖订单,请及时处理\",\"orderId\":\""+orderId+"\"}";
            }
            final String  sendMessage = message;
            //获取到所有的session 遍历所有的session ,取得所有session里面的webSocket对象 匹配userid和storeId
            Map<String, HttpSession> sessions = SessionListener.sessions;
            //遍历所有的session
            Set<String> keySets = sessions.keySet();
            for (String key : keySets) {
                HttpSession session =(HttpSession)sessions.get(key);
                Set<OrderRemind> orderReminds = (Set)session.getAttribute("webSocketObject");
                try {
                    if(orderReminds==null || orderReminds.size()==0){
                        continue;
                    }
                            for (OrderRemind orderRemind : orderReminds) {
                                if(storeId==orderRemind.storeId){
                                    logger.error("发送消息到客户端:{ userId:"+userId+" ---- orderId"+orderId+"---orderRemind.storeId:"+orderRemind.storeId+"}");
                                    orderRemind.session.getBasicRemote().sendText(sendMessage);
                                }
                            break;
                        }
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
    
    
    /* Set<Long> keys = userSocket.keySet(); for (Long userId : keys) { Set<OrderRemind> orderRemindes = userSocket.get(userId); for (OrderRemind orderRemind : orderRemindes) { //属于该门店的用户均发送推送消息 if(orderRemind.storeId==storeId){ try { logger.error("发送消息到客户端:{ userId:"+userId+" ---- orderId"+orderId+"---orderRemind.storeId:"+orderRemind.storeId+"}"); orderRemind.session.getBasicRemote().sendText(message); } catch (IOException e) { logger.error(" 给用户id为：{}发送消息失败",orderRemind.userId); e.printStackTrace(); } } } }*/
              return false;
          }
    
    
    }

结尾:仅供自己学习,记录问题和参考,若有带来误解和不便请见谅,共勉！

[http_example.com]: http://example.com