基于Spring 4.0 的 Web Socket 聊天室/游戏服务端简单架构

2023-08-22 17:26:55

在现在很多业务场景（比如聊天室），又或者是手机端的一些online游戏，都需要做到实时通信，那怎么来进行双向通信呢，总不见得用曾经很破旧的ajax每隔10秒或者每隔20秒来请求吧，我的天呐()，这尼玛太坑了

跟webservice来相比，Web Socket可以做到保持长连接，或者说强连接，一直握手存在两端可以互相发送消息互相收到消息，而webservice是一次性的，你要我响应就必须要请求我一次（黄盖：“请鞭挞我吧！”）

注：浏览器需要使用高版本的chrome或者Firefox，Tomcat使用8

先来了解一下基本概念

一、WebSocket是HTML5出的，是一种协议，也就是说原版的HTTP协议没有变化的，又或者说这两者压根就是不一样的东西，HTTP本身就不支持强连接
二、Websocket是什么样的协议，具体有什么优点
首先，Websocket是一个持久化的协议，相对于HTTP这种非持久的协议来说。
举个栗子吧，简单来说
1) HTTP的生命周期通过Request来界定，也就是一个Request 对应一个Response，或者多个Request 对应多个Response，
也就是说request对应的response数量是恒定不变的。而且这个response也是被动的，不能主动发起，必须有request才会有response

那么Websocket究竟是啥玩意呢
首先Websocket是基于HTTP协议的，或者说引用了HTTP的协议来完成一小部分的握手

简单来说，客服的发起请求到服务端，服务端找到对应的小弟（服务助理），找到好，这个小弟就会一直和老大保持联系，为老大服务

三、Websocket的作用

曾经接触WebSocket之前，我接触过ajax轮询以及long poll ，先来说说这2个概念，因为至今还有一些小项目是这么做的
ajax轮询：

原理非常简单，JS控制让浏览器隔个几秒就发送一次请求，询问服务器是否有新信息，有的话就响应给客户端
以此循环获取后端的数据，同时浏览器又不需要刷新

简单的例子：OA首页显示流程，每个几秒刷新看看有没有需要处理的新流程出现

long poll:
long poll 其实原理跟 ajax轮询差不多，都是采用循环的方式，不过采取的手段不太友好，是阻塞模型，客户端发起请求后，如果没响应，就一直不返回Response，直到有响应才返回，返回完之后，客户端再次建立连接，如此循环往复不亦乐乎。。。

从上面这两种方式看出他们都是在不断地建立HTTP连接，然后等待服务器处理，这样显得十分被动

那么缺点也随之而来：
这两种形式非常消耗资源，性能也不不好

好！接下来说说Websocket
Websocket的出现，使得资源不需要像之前那种方式那么浪费

它非常主动，服务端就可以主动推送信息给客户端
所以，只需建立一次HTTP请求，就可以做到源源不断的信息传送了。（就像你在手机上玩ol游戏，一开始建立连接后，你就一直保持在线，除非你断线再连）

下面贴出我的代码片段以及github地址

功能点：

spring websocket chating room
使用spring websocket实现聊天室基本功能
1.群发消息给所有人
2.悄悄话给某个人

效果：

主要代码：

pom.xml引入必要的库

 <?xml version="1.0" encoding="UTF-8"?>

 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">

     <modelVersion>4.0.0</modelVersion>

     <groupId>com.lee</groupId>

     <artifactId>websocket</artifactId>

     <name>maven-spring-websocket-01</name>

     <packaging>war</packaging>

     <version>1.0.0-BUILD-SNAPSHOT</version>

     <properties>

         <java.version>1.7</java.version>

         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>

         <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>

         <spring.version>4.0.0.RELEASE</spring.version>

         <junit.version>4.11</junit.version>

         <!-- Logging -->

         <logback.version>1.0.13</logback.version>

         <slf4j.version>1.7.7</slf4j.version>

     </properties>

     <dependencies>

         <!--spring MVC -->

         <dependency>

             <groupId>org.springframework</groupId>

             <artifactId>spring-core</artifactId>

             <version>${spring.version}</version>

         </dependency>

         <dependency>

             <groupId>org.springframework</groupId>

             <artifactId>spring-web</artifactId>

             <version>${spring.version}</version>

         </dependency>

         <dependency>

             <groupId>org.springframework</groupId>

             <artifactId>spring-webmvc</artifactId>

             <version>${spring.version}</version>

         </dependency>

         <!-- jstl -->

         <dependency>

             <groupId>jstl</groupId>

             <artifactId>jstl</artifactId>

             <version>1.2</version>

         </dependency>

         <!--spring测试框架 -->

         <dependency>

             <groupId>org.springframework</groupId>

             <artifactId>spring-test</artifactId>

             <version>${spring.version}</version>

             <scope>test</scope>

         </dependency>

         <!--spring数据库操作库 -->

         <dependency>

             <groupId>org.springframework</groupId>

             <artifactId>spring-jdbc</artifactId>

             <version>${spring.version}</version>

         </dependency>

         <dependency>

             <groupId>junit</groupId>

             <artifactId>junit</artifactId>

             <version>4.8.2</version>

             <scope>test</scope>

         </dependency>

         <!--spring websocket库 -->

         <dependency>

             <groupId>org.springframework</groupId>

             <artifactId>spring-websocket</artifactId>

             <version>${spring.version}</version>

         </dependency>

         <dependency>

             <groupId>org.springframework</groupId>

             <artifactId>spring-messaging</artifactId>

             <version>${spring.version}</version>

         </dependency>

         <!--jackson用于json操作 -->

         <dependency>

             <groupId>com.fasterxml.jackson.core</groupId>

             <artifactId>jackson-databind</artifactId>

             <version>2.3.0</version>

         </dependency>

         <dependency>

             <groupId>commons-fileupload</groupId>

             <artifactId>commons-fileupload</artifactId>

             <version>1.2.2</version>

         </dependency>

         <dependency>

             <groupId>commons-io</groupId>

             <artifactId>commons-io</artifactId>

             <version>2.2</version>

         </dependency>

         <!-- Logging with SLF4J & LogBack -->

         <dependency>

             <groupId>org.slf4j</groupId>

             <artifactId>slf4j-api</artifactId>

             <version>${slf4j.version}</version>

             <scope>compile</scope>

         </dependency>

         <dependency>

             <groupId>ch.qos.logback</groupId>

             <artifactId>logback-classic</artifactId>

             <version>${logback.version}</version>

             <scope>runtime</scope>

         </dependency>

         <!--使用阿里的连接池 -->

         <dependency>

             <groupId>com.alibaba</groupId>

             <artifactId>druid</artifactId>

             <version>1.0.4</version>

         </dependency>

         <!--mysql connector -->

         <dependency>

             <groupId>mysql</groupId>

             <artifactId>mysql-connector-java</artifactId>

             <version>5.1.29</version>

         </dependency>

     </dependencies>

     <build>

         <plugins>

             <plugin>

                 <groupId>org.apache.maven.plugins</groupId>

                 <artifactId>maven-compiler-plugin</artifactId>

                 <configuration>

                     <source>1.7</source>

                     <target>1.7</target>

                 </configuration>

             </plugin>

         </plugins>

     </build>

 </project>

主要结构

HandshakeInterceptor.java

 package com.lee.websocket;

 import java.util.Map;

 import javax.servlet.http.HttpSession;

 import org.springframework.http.server.ServerHttpRequest;

 import org.springframework.http.server.ServerHttpResponse;

 import org.springframework.http.server.ServletServerHttpRequest;

 import org.springframework.web.socket.WebSocketHandler;

 public class HandshakeInterceptor implements org.springframework.web.socket.server.HandshakeInterceptor {

     //进入hander之前的拦截

     @Override

     public boolean beforeHandshake(ServerHttpRequest request, ServerHttpResponse serverHttpResponse, WebSocketHandler webSocketHandler, Map<String, Object> map) throws Exception {

         if (request instanceof ServletServerHttpRequest) {

             ServletServerHttpRequest servletRequest = (ServletServerHttpRequest) request;

             String clientName = (String)servletRequest.getServletRequest().getParameter("name");

             System.out.println(clientName);

             HttpSession session = servletRequest.getServletRequest().getSession(true);

 //            String userName = "lee";

             if (session != null) {

                 //使用userName区分WebSocketHandler，以便定向发送消息

 //                String clientName = (String) session.getAttribute("WEBSOCKET_USERNAME");

                 map.put("WEBSOCKET_USERNAME", clientName);

             }

         }

         return true;

     }

     @Override

     public void afterHandshake(ServerHttpRequest serverHttpRequest, ServerHttpResponse serverHttpResponse, WebSocketHandler webSocketHandler, Exception e) {

     }

 }

HomeController.java

 package com.lee.websocket;

 import java.text.DateFormat;

 import java.util.Date;

 import java.util.Locale;

 import org.slf4j.Logger;

 import org.slf4j.LoggerFactory;

 import org.springframework.stereotype.Controller;

 import org.springframework.ui.Model;

 import org.springframework.web.bind.annotation.RequestMapping;

 import org.springframework.web.bind.annotation.RequestMethod;

 /**

  * Handles requests for the application home page.

  */

 @Controller

 public class HomeController {

     private static final Logger logger = LoggerFactory.getLogger(HomeController.class);

     /**

      * Simply selects the home view to render by returning its name.

      */

     @RequestMapping(value = "/", method = RequestMethod.GET)

     public String home(Locale locale, Model model) {

         logger.info("Welcome home! The client locale is {}.", locale);

         Date date = new Date();

         DateFormat dateFormat = DateFormat.getDateTimeInstance(DateFormat.LONG, DateFormat.LONG, locale);

         String formattedDate = dateFormat.format(date);

         model.addAttribute("serverTime", formattedDate );

         return "home";

     }

     @RequestMapping(value = "/chat", method = RequestMethod.GET)

     public String chat(Locale locale, Model model) {

         return "chat";

     }

 }

WebSocketConfig.java

 package com.lee.websocket;

 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;

 @Configuration

 @EnableWebSocket//开启websocket

 public class WebSocketConfig implements WebSocketConfigurer {

     @Override

     public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {

         registry.addHandler(new WebSocketHander(),"/echo").addInterceptors(new HandshakeInterceptor()); //支持websocket 的访问链接

         registry.addHandler(new WebSocketHander(),"/sockjs/echo").addInterceptors(new HandshakeInterceptor()).withSockJS(); //不支持websocket的访问链接

     }

 }

WebSocketHander.java

 package com.lee.websocket;

 import java.io.IOException;

 import java.util.ArrayList;

 import org.slf4j.Logger;

 import org.slf4j.LoggerFactory;

 import org.springframework.web.socket.CloseStatus;

 import org.springframework.web.socket.TextMessage;

 import org.springframework.web.socket.WebSocketHandler;

 import org.springframework.web.socket.WebSocketMessage;

 import org.springframework.web.socket.WebSocketSession;

 public class WebSocketHander implements WebSocketHandler {

     private static final Logger logger = LoggerFactory.getLogger(WebSocketHander.class);

     private static final ArrayList<WebSocketSession> users = new ArrayList<>();

     //初次链接成功执行

     @Override

     public void afterConnectionEstablished(WebSocketSession session) throws Exception {

         logger.debug("链接成功......");

         users.add(session);

         String userName = (String) session.getHandshakeAttributes().get("WEBSOCKET_USERNAME");

         if(userName!= null){

             session.sendMessage(new TextMessage("欢迎来到Nathan的聊天室，我们开始聊天吧！~"));

         }

     }

     //接受消息处理消息

     @Override

     public void handleMessage(WebSocketSession session, WebSocketMessage<?> webSocketMessage) throws Exception {

         String clientName = (String) session.getHandshakeAttributes().get("WEBSOCKET_USERNAME");

         clientName = "<a onclick='changeChater(this)'>" + clientName + "</a>";

         String msg = webSocketMessage.getPayload().toString();

         String charter = "";

         String msgs[] = msg.split("\\|");

         if (msgs.length > 1) {

             msg = msgs[1];

             charter = msgs[0];

             sendMessageToUser(charter, new TextMessage(clientName + "  悄悄地对你说 ：" + msg));

         } else {

             sendMessageToUsers(new TextMessage(clientName + "  说：" + msg));

         }

     }

     @Override

     public void handleTransportError(WebSocketSession webSocketSession, Throwable throwable) throws Exception {

         if(webSocketSession.isOpen()){

             webSocketSession.close();

         }

         logger.debug("链接出错，关闭链接......");

         users.remove(webSocketSession);

     }

     @Override

     public void afterConnectionClosed(WebSocketSession webSocketSession, CloseStatus closeStatus) throws Exception {

         logger.debug("链接关闭......" + closeStatus.toString());

         users.remove(webSocketSession);

     }

     @Override

     public boolean supportsPartialMessages() {

         return false;

     }

     /**

      * 给所有在线用户发送消息

      *

      * @param message

      */

     public void sendMessageToUsers(TextMessage message) {

         for (WebSocketSession user : users) {

             try {

                 if (user.isOpen()) {

                     user.sendMessage(message);

                 }

             } catch (IOException e) {

                 e.printStackTrace();

             }

         }

     }

     /**

      * 给某个用户发送消息

      *

      * @param userName

      * @param message

      */

     public void sendMessageToUser(String userName, TextMessage message) {

         for (WebSocketSession user : users) {

             if (user.getHandshakeAttributes().get("WEBSOCKET_USERNAME").equals(userName)) {

                 try {

                     if (user.isOpen()) {

                         user.sendMessage(message);

                     }

                 } catch (IOException e) {

                     e.printStackTrace();

                 }

                 break;

             }

         }

     }

 }

Person.java

 package com.lee.websocket.entity;

 public class Person {

     private int age;

     private String name;

     private String sex;

     public int getAge() {

         return age;

     }

     public void setAge(int age) {

         this.age = age;

     }

     public String getName() {

         return name;

     }

     public void setName(String name) {

         this.name = name;

     }

     public String getSex() {

         return sex;

     }

     public void setSex(String sex) {

         this.sex = sex;

     }

 }

chat.jsp

 <%@ page contentType="text/html; charset=utf-8" language="java" %>

 <html>

 <head lang="en">

     <meta charset="UTF-8">

     <script src="http://cdn.sockjs.org/sockjs-0.3.min.js"></script>

     <!-- 新 Bootstrap 核心 CSS 文件 -->

     <link rel="stylesheet" href="//cdn.bootcss.com/bootstrap/3.3.5/css/bootstrap.min.css">

     <!-- 可选的Bootstrap主题文件（一般不用引入） -->

     <link rel="stylesheet" href="//cdn.bootcss.com/bootstrap/3.3.5/css/bootstrap-theme.min.css">

     <!-- jQuery文件。务必在bootstrap.min.js 之前引入 -->

     <script src="//cdn.bootcss.com/jquery/1.11.3/jquery.min.js"></script>

     <!--<script type="text/javascript" src="js/jquery-1.7.2.js"></script>-->

     <!-- 最新的 Bootstrap 核心 JavaScript 文件 -->

     <script src="//cdn.bootcss.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>

     <title>webSocket测试</title>

     <script type="text/javascript">

         var chater;

         $(function(){

             var websocket;

             function connectServer() {

                 var clientName = $("#client_name").val();

                 if ("WebSocket" in window) {

                     websocket = new WebSocket("ws://127.0.0.1:8080/websocket/echo?name=" + clientName);

                 } else if ("MozWebSocket" in window) {

                     alert("MozWebSocket");

                     websocket = new MozWebSocket("ws://echo");

                 } else {

                     alert("SockJS");

                     websocket = new SockJS("http://127.0.0.1:8080/websocket/sockjs/echo");

                 }

             }

 //             websocket.onopen = function (evnt) {

 //                 $("#tou").html("链接服务器成功!")

 //             };

 //             websocket.onmessage = function (evnt) {

 //                 $("#msg").html($("#msg").html() + "<br/>" + evnt.data);

 //             };

 //             websocket.onerror = function (evnt) {

 //             };

 //             websocket.onclose = function (evnt) {

 //                 $("#tou").html("与服务器断开了链接!")

 //             }

             $("#conncet_server").bind("click", function() {

                 connectServer();

                 websocket.onopen = function (evnt) {

                     $("#tou").html("链接服务器成功!")

                 };

                 websocket.onmessage = function (evnt) {

                     $("#msg").html($("#msg").html() + "<br/>" + evnt.data);

                 };

                 websocket.onerror = function (evnt) {

                 };

                 websocket.onclose = function (evnt) {

                     $("#tou").html("与服务器断开了链接!")

                 }

             });

             $("#send").bind("click", function() {

                 send();

             });

             function send(){

                 if (websocket != null) {

                     var message = document.getElementById("message").value;

                     if ($.trim(chater) != "") {

                         message = chater + "|" + message;

                     }

                     websocket.send(message);

                 } else {

                     alert("未与服务器链接.");

                 }

             }

         });

         function changeChater(e) {

             chater = $(e).html();

             alert("您将和" + chater + "进行聊天...");

         }

     </script>

 </head>

 <body>

     <div class="page-header" id="tou">webSocket及时聊天Demo程序</div>

     <div class="well" id="msg"></div>

     <div class="col-lg">

         <div class="input-group">

             <input type="text" class="form-control" placeholder="请输入用户名..." id="client_name">

             <span class="input-group-btn">

                 <button class="btn btn-default" type="button" id="conncet_server">连接服务器</button>

             </span>

         </div>

     </div>

     <br/>

     <div class="col-lg">

         <div class="input-group">

             <input type="text" class="form-control" placeholder="发送信息..." id="message">

             <span class="input-group-btn">

                 <button class="btn btn-default" type="button" id="send">发送</button>

             </span>

         </div>

     </div>

 </body>

 </html>

有兴趣的朋友可以关注github地址：https://github.com/leechenxiang/maven-spring-websocket-01

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