历经一周把整个消息模块开发完毕,其中在websocket这块遇到比较多的问题是中文乱码,因为项目中用ajax跟后端交互,用@Response注解时候出现中文乱码,需要Spring MVC相关配置,这块遇到配置会在另一个文章体现。
鉴于网上提供的一些文章,都介绍不是很到位,关键部分都没体现,导致在真实项目中出现各种各样的问题。
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环境介绍:
Jdk 1.7
Tomcat7.0.52 (支持Websocket协议)
Spring4.0.26 (支持Websocket)
web.xml(配置了前端自动优化HtmlCompressor和Druid监控),自动优化会影响Websocket js脚本,后面会讲
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配置步骤:
1. 引入Spring相关Jar,特别需要下面这两个
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-websocket</artifactId>
<version>4.0.6.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-messaging</artifactId>
<version>4.0.6.RELEASE</version>
</dependency>
2. 编写WebSocketConfig implements WebSocketConfigurer
WebSocketConfig.java
import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.web.servlet.config.annotation.EnableWebMvc; 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; import org.springframework.web.socket.handler.TextWebSocketHandler; import cn.com.ship.message.handler.ChatMessageHandler; import cn.com.ship.message.handler.TextMessageHandler; @Configuration <strong><span style="color:#ff0000;">//@EnableWebMvc//这个标注可以不加,如果有加,要</span><span style="color:#ff0000;"><strong><span style="color:#ff0000;">extends WebMvcConfigurerAdapter</span></strong></span></strong> @EnableWebSocket public class WebSocketConfig implements WebSocketConfigurer { @Override public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) { registry.addHandler(chatMessageHandler(),"/websocket/chatMessageServer.do").addInterceptors(new ChatHandshakeInterceptor()); registry.addHandler(chatMessageHandler(), "/sockjs/chatMessageServer.do").addInterceptors(new ChatHandshakeInterceptor()).withSockJS(); } @Bean public TextWebSocketHandler chatMessageHandler(){ return new ChatMessageHandler(); } }
3. 编写ChatMessageHandler extends TextWebSocketHandler
ChatMessageHandler.java
import java.io.IOException; import java.util.ArrayList; import org.apache.log4j.Logger; import org.springframework.web.socket.CloseStatus; import org.springframework.web.socket.TextMessage; import org.springframework.web.socket.WebSocketSession; import org.springframework.web.socket.handler.TextWebSocketHandler; import cn.com.ship.message.common.Constants; import cn.com.ship.message.common.MessageCriteria; public class ChatMessageHandler extends TextWebSocketHandler{ private static final ArrayList<WebSocketSession> users;//这个会出现性能问题,最好用Map来存储,key用userid private static Logger logger = Logger.getLogger(ChatMessageHandler.class); static { users = new ArrayList<WebSocketSession>(); } public ChatMessageHandler() { // TODO Auto-generated constructor stub } /** * 连接成功时候,会触发UI上onopen方法 */ @Override public void afterConnectionEstablished(WebSocketSession session) throws Exception { System.out.println("connect to the websocket success......"); users.add(session); //这块会实现自己业务,比如,当用户登录后,会把离线消息推送给用户 //TextMessage returnMessage = new TextMessage("你将收到的离线"); //session.sendMessage(returnMessage); } /** * 在UI在用js调用websocket.send()时候,会调用该方法 */ @Override protected void handleTextMessage(WebSocketSession session, TextMessage message) throws Exception { super.handleTextMessage(session, message); } /** * 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.getAttributes().get(Constants.WEBSOCKET_USERNAME).equals(userName)) { try { if (user.isOpen()) { user.sendMessage(message); } } catch (IOException e) { e.printStackTrace(); } break; } } } /** * 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(); } } } @Override public void handleTransportError(WebSocketSession session, Throwable exception) throws Exception { if(session.isOpen()){ session.close(); } logger.debug("websocket connection closed......"); users.remove(session); } @Override public void afterConnectionClosed(WebSocketSession session, CloseStatus closeStatus) throws Exception { logger.debug("websocket connection closed......"); users.remove(session); } @Override public boolean supportsPartialMessages() { return false; } }
4. 编写websocket握手拦截器ChatHandshakeInterceptor extends HttpSessionHandshakeInterceptor
ChatHandshakeInterceptor.java
package cn.com.ship.message.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; import org.springframework.web.socket.server.support.HttpSessionHandshakeInterceptor; import cn.com.ship.message.common.Constants; public class ChatHandshakeInterceptor extends HttpSessionHandshakeInterceptor { @Override public boolean beforeHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler wsHandler, Map<String, Object> attributes) throws Exception { System.out.println("Before Handshake"); if (request instanceof ServletServerHttpRequest) { ServletServerHttpRequest servletRequest = (ServletServerHttpRequest) request; HttpSession session = servletRequest.getServletRequest().getSession(false); if (session != null) { //使用userName区分WebSocketHandler,以便定向发送消息 String userName = (String) session.getAttribute(Constants.SESSION_USERNAME); if (userName==null) { userName="default-system"; } attributes.put(Constants.WEBSOCKET_USERNAME,userName); } } return super.beforeHandshake(request, response, wsHandler, attributes); } @Override public void afterHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler wsHandler, Exception ex) { System.out.println("After Handshake"); super.afterHandshake(request, response, wsHandler, ex); } }
4. 重点在Spring mvc相关配置(经常出现问题就是:中文乱码,如果是用ajax交互)
<?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:jee="http://www.springframework.org/schema/jee" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:p="http://www.springframework.org/schema/p" xmlns:util="http://www.springframework.org/schema/util" xmlns:tool="http://www.springframework.org/schema/tool" xmlns:context="http://www.springframework.org/schema/context" xmlns:task="http://www.springframework.org/schema/task" 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/tx http://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util.xsd http://www.springframework.org/schema/tool http://www.springframework.org/schema/tool/spring-tool.xsd http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task.xsd http://www.springframework.org/schema/websocket http://www.springframework.org/schema/websocket/spring-websocket-4.1.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.1.xsd"> <!-- 这个bean要放在context:component-scan这个前面,不然会出现中文乱码 --> <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter"> <property name="messageConverters"> <list> <ref bean="stringHttpMessageConverter" /> <ref bean="byteArrayHttpMessageConverter" /> <ref bean="jsonHttpMessageConverter" /> <ref bean="jsonHttpMessageConverter4JS" /> </list> </property> </bean> <!-- 启动SpringMVC Controller的注解功能,完成请求和注解POJO的映射 --> <context:component-scan base-package="cn.com.ship.*.**.controller" /> <!-- websocket相关扫描,主要扫描:WebSocketConfig.java 这个类路径 --> <context:component-scan base-package="cn.com.ship.message.websocket"/> <!-- 下面标签可以不加 等价于所有component-scan--> <context:annotation-config /> <!-- 这个重点,标注必须加,websocket用到--> <mvc:annotation-driven/> <bean id="byteArrayHttpMessageConverter" class="org.springframework.http.converter.ByteArrayHttpMessageConverter" /> <bean id="stringHttpMessageConverter" class="org.springframework.http.converter.StringHttpMessageConverter"> <property name="supportedMediaTypes"> <list> <value>text/plain;charset=UTF-8</value> </list> </property> </bean> <bean id="jsonHttpMessageConverter" class="cn.com.ship.external.spring.converter.json.MappingJackson2HttpMessageConverter"> <property name="objectMapper"> <bean class="com.fasterxml.jackson.databind.ObjectMapper"> <!--对属性值为null的不序列化反序列化--> <property name="serializationInclusion"> <util:constant static-field="com.fasterxml.jackson.annotation.JsonInclude.Include.NON_NULL"/> </property> </bean> </property> <property name="supportedMediaTypes"> <list> <value>application/json</value> </list> </property> </bean> <bean id="jsonHttpMessageConverter4JS" class="cn.com.ship.external.spring.converter.json.MappingJackson2HttpMessageConverter"> <property name="objectMapper"> <bean class="com.fasterxml.jackson.databind.ObjectMapper"> <property name="dateFormat"> <bean class="java.text.SimpleDateFormat"> <constructor-arg type="java.lang.String" value="yyyy-MM-dd HH:mm:ss" /> </bean> </property> <!--对属性值为null的不序列化反序列化--> <property name="serializationInclusion"> <util:constant static-field="com.fasterxml.jackson.annotation.JsonInclude.Include.NON_NULL"/> </property> </bean> </property> <property name="supportedMediaTypes"> <list> <value>text/json</value> </list> </property> </bean> <bean id="viewResolver" class="org.springframework.web.servlet.view.UrlBasedViewResolver"> <property name="viewClass" value="org.springframework.web.servlet.view.JstlView" /> <property name="prefix" value="/" /> <property name="suffix" value=".jsp" /> </bean> <!-- 文件上传配置 --> <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver" p:defaultEncoding="utf-8"> <property name="maxUploadSize" value="1024000000" /> <property name="resolveLazily" value="true" /> </bean> </beans>
注意:MappingJackson2HttpMessageConverter.java,来自Spring代码,并且修改了一点点,这个找到附件位置下载
5. jsp相关Websocket脚本编写
ws.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <html> <head> <title>Java API for WebSocket (JSR-356)</title> </head> <body> <script type="text/javascript" src="http://localhost:8080/ship/js/jquery/jquery.min.js"></script> <script type="text/javascript" src="http://localhost:8080/ship/js/sockjs-0.3.4.min.js"></script> <script type="text/javascript"> var websocket = null; if ('WebSocket' in window) { websocket = new WebSocket("ws://localhost:8080/ship/webSocketServer.do"); } else if ('MozWebSocket' in window) { websocket = new MozWebSocket("ws://localhost:8080/ship/webSocketServer.do"); } else { websocket = new SockJS("http://localhost:8080/ship/sockjs/webSocketServer.do"); } websocket.onopen = onOpen; websocket.onmessage = onMessage; websocket.onerror = onError; websocket.onclose = onClose; function onOpen(openEvt) { //alert(openEvt.Data); } function onMessage(evt) { alert(evt.data); } function onError() {} function onClose() {} function doSend() { if (websocket.readyState == websocket.OPEN) { var msg = document.getElementById("inputMsg").value; websocket.send(msg);//调用后台handleTextMessage方法 alert("发送成功!"); } else { alert("连接失败!"); } } </script> 请输入:<textarea rows="5" cols="10" id="inputMsg" name="inputMsg"></textarea> <button onclick="doSend();">发送</button> </body> </html>
login.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Java API for WebSocket (JSR-356)</title> </head> <body> <!-ship是我的项目名--> <form action="/ship/websocket/login.do"> 登录名:<input type="text" name="username"/> <input type="submit" value="登录"/> </form> </body> </html>
5. 调用端Controller编写 WebsocketController.java
package cn.com.ship.websocket.controller; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.ResponseBody; @Controller public class WebsocketController { @Bean//这个注解会从Spring容器拿出Bean public InfoHandler infoHandler() { return new InfoHandler(); } @RequestMapping("/websocket/login") public void login(HttpServletRequest request, HttpServletResponse response) throws Exception { String username = request.getParameter("username"); HttpSession session = request.getSession(false); session.setAttribute(Constants.SESSION_USERNAME, username); response.sendRedirect("/ship/websocket/ws.jsp"); } @RequestMapping("/websocket/send") @ResponseBody public String send(HttpServletRequest request) { String username = request.getParameter("username"); infoHandler().sendMessageToUser(username, new TextMessage("你好,测试!!!!")); return null; } }
6. 测试Websocket是否连接成功
先在login.jsp上随便输入用户名,然后WebsocketController处理完请求,会重定向到ws.jsp
如果后台打印出现消息,证明Websocket连接成功(前两名消息是在ChatHandshakeInterceptor.java,最后一句是在ChatMessageHandler.java)