Java中Spring WebSocket详解
首先 pom.xml
<parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.5.8.RELEASE</version> </parent> <dependency> <groupId>org.apache.commons</groupId> <artifactId>commons-io</artifactId> </dependency> <dependency> <groupId>javax.websocket</groupId> <artifactId>javax.websocket-api</artifactId> <version>1.0</version> <scope>provided</scope> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-websocket</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</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-undertow</artifactId> </dependency>
接收消息后的处理类 GameHandler :
import java.net.URI; import org.springframework.web.socket.BinaryMessage; import org.springframework.web.socket.CloseStatus; import org.springframework.web.socket.PongMessage; import org.springframework.web.socket.TextMessage; import org.springframework.web.socket.WebSocketSession; import org.springframework.web.socket.handler.AbstractWebSocketHandler; public class GameHandler extends AbstractWebSocketHandler { /** * 处理字符串类的信息 * * @param session * @param message * @throws Exception */ @Override protected void handleTextMessage(WebSocketSession session, TextMessage message) throws Exception { session.sendMessage(new TextMessage(message.asBytes())); } /** * 处理二进制类的信息 * * @param session * @param message * @throws Exception */ @Override protected void handleBinaryMessage(WebSocketSession session, BinaryMessage message) throws Exception { session.sendMessage(new BinaryMessage(message.getPayload())); } /** * ping-pong * * @param session * @param message * @throws Exception */ @Override protected void handlePongMessage(WebSocketSession session, PongMessage message) throws Exception { } /** * 传出错误的处理 * * @param session * @param exception * @throws Exception */ @Override public void handleTransportError(WebSocketSession session, Throwable exception) throws Exception { } /** * 连接关闭的处理 * * @param session * @param status * @throws Exception */ @Override public void afterConnectionClosed(WebSocketSession session, CloseStatus status) throws Exception { } /** * 连接建立后的处理 * * @param session * @throws Exception */ @Override public void afterConnectionEstablished(WebSocketSession session) throws Exception { } }
握手信息拦截器 WebSocketHandshakeInterceptor :
import java.util.Map; import javax.servlet.http.Cookie; 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; public class WebSocketHandshakeInterceptor implements HandshakeInterceptor { @Override public boolean beforeHandshake(ServerHttpRequest request, ServerHttpResponse shr1, WebSocketHandler wsh, Map<String, Object> attributes) throws Exception { // 此处可以做一些权限认证的事情或者其他 return true; } @Override public void afterHandshake(ServerHttpRequest shr, ServerHttpResponse shr1, WebSocketHandler wsh, Exception excptn) { } }
使用WebSocket的配置类 WebSocketConfig :
import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter; 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 public class WebSocketConfig extends WebMvcConfigurerAdapter implements WebSocketConfigurer { @Override public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) { // 允许连接的域,只能以http或https开头 String[] allowsOrigins = {"http://127.0.0.1:1213", "http://localhost:1213"}; registry.addHandler(gameHandler(),"/game").addInterceptors(handshakeInterceptor()).setAllowedOrigins(allowsOrigins); } @Bean public GameHandler gameHandler() { return new GameHandler(); } @Bean public WebSocketHandshakeInterceptor handshakeInterceptor() { return new WebSocketHandshakeInterceptor(); } }
启动类 Launcher :
@SpringBootApplication public class Launcher { public static void main(String[] params) { SpringApplication.run(Launcher.class, params); } }
配置文件 main/resources/application.properties:
server.port=1213 server.session-timeout=1800 server.undertow.io-threads=4 server.undertow.worker-threads=20 server.undertow.buffer-size=1024 server.undertow.buffers-per-region=1024 server.undertow.direct-buffers=true
前端的测试页面 main\resources\static\index.html
<!DOCTYPE html> <html lang="zh-CN"> <head> <meta charset="utf-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <meta name="viewport" content="width=device-width, initial-scale=1"> <title>Platform Gateway</title> <link href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="external nofollow" rel="stylesheet"> <!--<link href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap-theme.min.css" rel="external nofollow" rel="stylesheet">--> <script src="https://cdn.bootcss.com/jquery/3.2.1/jquery.min.js"></script> <script src="https://cdn.bootcss.com/jquery-scrollTo/2.1.2/jquery.scrollTo.min.js"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/pako/1.0.6/pako.min.js"></script> <!--[if lt IE 9]> <script src="https://cdn.bootcss.com/html5shiv/3.7.3/html5shiv.min.js"></script> <script src="https://cdn.bootcss.com/respond.js/1.4.2/respond.min.js"></script> <![endif]--> <style> #message{ height: 600px; overflow-y:auto; } </style> </head> <body> <div class="container"> <h1>WebSocket Test Page</h1> <hr/> <div class="form-inline"> <div class="form-group"> <label for="wsAddr">WebSocket Address: </label> <div class="input-group"> <span class="input-group-addon" id="basic-ws">ws://127.0.0.1:1213/</span> <input type="text" class="form-control" id="basic-ws-addr" aria-describedby="basic-ws" placeholder="game" data-container="body" data-placement="top" data-content="链接地址不能为空,请填写"> </div> </div> <button type="button" id="btnConnect" class="btn btn-primary" onclick="connect();"> <span class="glyphicon glyphicon-resize-small" aria-hidden="true"></span> 连接 </button> <button type="button" id="btnClose" class="btn btn-danger" disabled="disabled" onclick="closeWebSocket();"> <span class="glyphicon glyphicon-remove" aria-hidden="true"></span> 断开 </button> <button type="button" id="btnSend" class="btn btn-info" disabled="disabled" style="margin-left: 50px;" onclick="send();"> <span class="glyphicon glyphicon-transfer" aria-hidden="true"></span> 发送消息 </button> </div><br/> <textarea class="form-control" id="inMsg" rows="5" placeholder="在这里输入需要发送的信息..."></textarea> <hr/> <div id="message"></div> </div> <script src="https://cdn.bootcss.com/bootstrap/3.3.7/js/bootstrap.min.js"></script> <script type="text/javascript"> function zip(str) { var binaryString = pako.gzip(str, {to: 'string'}); return btoa(binaryString); } function unzip(b64Data) { var strData = atob(b64Data); var charData = strData.split('').map(function (x) { return x.charCodeAt(0); }); var binData = new Uint8Array(charData); var data = pako.inflate(binData); strData = String.fromCharCode.apply(null, new Uint16Array(data)); return strData; } var websocket = null; var wsBaseUrl = null; var wsUrl = null; function init() { wsBaseUrl = "ws://" + window.location.host + "/"; $("#basic-ws").text(wsBaseUrl); $(function () { $('[data-toggle="popover"]').popover(); }); return false; } //关闭WebSocket连接 function closeWebSocket() { if (websocket) { websocket.close(); } return false; } //将消息显示在网页上 function setMessageInnerHTML(who, msg) { var message = null; if (who === 1) { message = '<div class="alert alert-success" role="alert">本地: ' + msg + '</div>'; } else { message = '<div class="alert alert-info" role="alert">服务器: ' + msg + '</div>'; } document.getElementById('message').innerHTML = (document.getElementById('message').innerHTML + message); $("#message").scrollTo('100%'); return false; } //发送消息 function send() { if (websocket) { var message = $("#inMsg").val(); websocket.send(zip(message)); setMessageInnerHTML(1, message); } return false; } function connect() { var url = $("#basic-ws-addr").val(); if (url.length <= 0) { $('#basic-ws-addr').popover('show'); setTimeout(function () { $('#basic-ws-addr').popover('hide'); }, 3000); } else { wsUrl = wsBaseUrl + url; if ('WebSocket' in window) { websocket = new WebSocket(wsUrl); //连接发生错误的回调方法 websocket.onerror = function () { setMessageInnerHTML(0, "WebSocket连接发生错误 -> " + wsUrl); $("#btnConnect").removeAttr("disabled"); $("#btnClose").attr("disabled", "disabled"); $("#btnSend").attr("disabled", "disabled"); }; //连接成功建立的回调方法 websocket.onopen = function () { setMessageInnerHTML(0, "WebSocket连接成功 -> " + wsUrl); $("#btnConnect").attr("disabled", "disabled"); $("#btnClose").removeAttr("disabled"); $("#btnSend").removeAttr("disabled"); }; //接收到消息的回调方法 websocket.onmessage = function (event) { setMessageInnerHTML(0, unzip(event.data)); }; //连接关闭的回调方法 websocket.onclose = function () { setMessageInnerHTML(0, "WebSocket连接关闭 -> " + wsUrl); $("#btnConnect").removeAttr("disabled"); $("#btnClose").attr("disabled", "disabled"); $("#btnSend").attr("disabled", "disabled"); }; //监听窗口关闭事件,当窗口关闭时,主动去关闭websocket连接,防止连接还没断开就关闭窗口,server端会抛异常。 window.onbeforeunload = function () { closeWebSocket(); }; } else { alert('Not support websocket'); } } return false; } window.onload = init(); </script> </body> </html>
到此就可以使用 WebSocket 进行前后端的通信了,如果大家还有不明白的或者有更好的方法,可以在下方的留言区讨论。
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