spring 5.x 系列第17篇 —— 整合websocket (xml配置方式)

源码Gitub地址：https://github.com/heibaiying/spring-samples-for-all

一、说明

1.1 项目结构说明

1. 项目模拟一个简单的群聊功能，为区分不同的聊天客户端，登录时候将临时用户名存储在session当中；
2. CustomHander为消息的自定义处理器；
3. CustomHandershakerInterceptor为自定义的 websocket 的握手拦截器；
4. 项目以web的方式构建。

1.2 依赖说明

除了基本的spring 依赖外，还需要导入webSocket的依赖包

<!--spring webSocket 的依赖包 --><dependency> <groupId>org.springframework</groupId> <artifactId>spring-websocket</artifactId> <version>5.1.3.RELEASE</version></dependency>

二、spring websocket

2.1 创建消息处理类，继承自TextWebSocketHandler

/** * @author : heibaiying * @description : 自定义消息处理类 */public class CustomHandler extends TextWebSocketHandler { private Map<String, WebSocketSession> nameAndSession = new ConcurrentHashMap<>(); // 建立连接时候触发 @Override public void afterConnectionEstablished(WebSocketSession session) { String username = getNameFromSession(session); nameAndSession.putIfAbsent(username, session); } // 关闭连接时候触发 @Override public void afterConnectionClosed(WebSocketSession session, CloseStatus status) { String username = getNameFromSession(session); nameAndSession.remove(username); } // 处理消息 @Override protected void handleTextMessage(WebSocketSession session, TextMessage message) throws Exception { // 防止中文乱码 String msg = URLDecoder.decode(message.getPayload(), "utf-8"); String username = getNameFromSession(session); // 简单模拟群发消息 TextMessage reply = new TextMessage(username + " : " + msg); nameAndSession.forEach((s, webSocketSession) -> { try { webSocketSession.sendMessage(reply); } catch (IOException e) { e.printStackTrace(); } }); } private String getNameFromSession(WebSocketSession session) { Map<String, Object> attributes = session.getAttributes(); return (String) attributes.get(Constant.USER_NAME); }}

2.2 创建websocket 握手拦截器（如果没有权限拦截等需求，这一步不是必须的）

/** * @author : heibaiying * @description : 可以按照需求实现权限拦截等功能 */public class CustomHandshakeInterceptor extends HttpSessionHandshakeInterceptor { @Override public boolean beforeHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler wsHandler, Map<String, Object> attributes) throws Exception { InetSocketAddress remoteAddress = request.getRemoteAddress(); InetAddress address = remoteAddress.getAddress(); System.out.println(address); /* * 最后需要要显示调用父类方法，父类的beforeHandshake方法 * 把ServerHttpRequest 中session中对应的值拷贝到WebSocketSession中。 * 如果我们没有实现这个方法，我们在最后的handler处理中 是拿不到 session中的值 * 作为测试 可以注释掉下面这一行 可以发现自定义处理器中session的username总是为空 */ return super.beforeHandshake(request, response, wsHandler, attributes); }}

2.3 配置websocket

<?xml version="1.0" encoding="UTF-8"?><beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:websocket="http://www.springframework.org/schema/websocket" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.1.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.1.xsd http://www.springframework.org/schema/websocket http://www.springframework.org/schema/websocket/spring-websocket.xsd"> <!-- 开启注解包扫描--> <context:component-scan base-package="com.heibaiying.*"/> <!--使用默认的Servlet来响应静态文件 --> <mvc:default-servlet-handler/> <!-- 开启注解驱动 --> <mvc:annotation-driven/> <!-- 配置视图解析器 --> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" id="internalResourceViewResolver"> <!-- 前缀 --> <property name="prefix" value="/WEB-INF/jsp/"/> <!-- 后缀 --> <property name="suffix" value=".jsp"/> </bean> <!--配置webSocket--> <bean id="customHandler" class="com.heibaiying.websocket.CustomHandler"/> <websocket:handlers> <!--指定webSocket 地址--> <websocket:mapping path="/socket" handler="customHandler"/> <!--webSocket握手--> <websocket:handshake-interceptors> <bean class="com.heibaiying.websocket.CustomHandshakeInterceptor"/> </websocket:handshake-interceptors> </websocket:handlers></beans>

2.4 前端 websocket 的实现

<%@ page contentType="text/html;charset=UTF-8" language="java" %><html><head> <title>${sessionScope.get("username")}您好！欢迎进入群聊大厅！</title></head><body><input id="message" type="text"><button id="btn">发送消息</button><div id="show"></div><script> let btn = document.getElementById("btn"); let message = document.getElementById("message"); let show = document.getElementById("show"); let ws = new WebSocket("ws://localhost:8080/socket"); ws.onmessage = function (evt) { let node = document.createElement("div"); node.innerHTML = "<h5>" + evt.data + "</h5>"; show.appendChild(node); }; btn.addEventListener("click", function () { let data = message.value; console.log(data); if (data) { ws.send(encodeURI(data)); } else { alert("请输入消息后发送"); } message.value = ""; }); // 关闭页面时候关闭ws window.addEventListener("beforeunload", function(event) { ws.close(); });</script></body></html>

2.5 简单登录的实现

<%@ page contentType="text/html;charset=UTF-8" language="java" %><html><head> <title>Title</title></head><body><form action="${pageContext.request.contextPath}/login" method="post"> <input name="username" type="text"> <button id="btn">输入临时用户名后登录！</button></form></body></html>

@Controllerpublic class LoginController { @PostMapping("login") public String login(String username, HttpSession session){ session.setAttribute(Constant.USER_NAME,username); return "chat"; }}

附：源码Gitub地址：https://github.com/heibaiying/spring-samples-for-all