在SpringMVC中使用WebSocket

2019-11-10 17:19:38

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SPRingMvc項目的搭建在這里就不做多解釋，要在Spring中實現 WebSocket 必須加上 spring-websocket和 spring-messaging兩個包，同樣，完整的pom.xml給出如下:<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.656463</groupId> <artifactId>demo-websocket</artifactId> <packaging>war</packaging> <name>demo-websocket Maven Webapp</name> <version>0.0.1-SNAPSHOT</version> <url>http://maven.apache.org</url> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <spring.version>4.1.6.RELEASE</spring.version> </properties> <dependencies>  <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-beans</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-aop</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context-support</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-jdbc</artifactId> <version>${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> <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> <dependency> <groupId>org.aspectj</groupId> <artifactId>aspectjweaver</artifactId> <version>1.7.4</version> </dependency> <dependency> <groupId>com.google.code.gson</groupId> <artifactId>gson</artifactId> <version>2.7</version> </dependency> <dependency> <groupId>jstl</groupId> <artifactId>jstl</artifactId> <version>1.2</version> </dependency> <dependency> <groupId>taglibs</groupId> <artifactId>standard</artifactId> <version>1.1.2</version> </dependency> <dependency> <groupId>javax.websocket</groupId> <artifactId>javax.websocket-api</artifactId> <version>1.1</version> <scope>provided</scope> </dependency> <dependency> <groupId>javax</groupId> <artifactId>javaee-api</artifactId> <version>7.0</version> <scope>provided</scope> </dependency> </dependencies> <build> <finalName>demo-websocket</finalName> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <version>3.0</version> <configuration> <source>1.7</source> <target>1.7</target> </configuration> </plugin> <plugin> <groupId>org.apache.tomcat.maven</groupId> <artifactId>tomcat7-maven-plugin</artifactId> <version>2.2</version> <configuration> <port>8080</port> <path>/</path> </configuration> </plugin> </plugins> </build></project>定義一個簡單的WebSocket客戶端頁面，這里只有一個連接和發送消息的功能，這個示例和上個示例的功能類似<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" %><!DOCTYPE html><html lang="en"><head> <meta charset="utf-8"> <title></title> <script type="text/Javascript" src="/static/js/jquery-1.9.1.js"></script> <script type="text/javascript"> $(function () { var websocket; var target = "ws://192.168.56.101:8080/hello.htm"; if ('WebSocket' in window) { websocket = new WebSocket(target); } else if ('MozWebSocket' in window) { websocket = new MozWebSocket(target); } else { alert('WebSocket is not supported by this browser.'); return; } websocket.onopen = function (evnt) { $("#tou").html("鏈接服務器成功!") }; websocket.onmessage = function (evnt) { $("#msg").html($("#msg").html() + "<br/>" + evnt.data); }; websocket.onerror = function (evnt) { }; websocket.onclose = function (evnt) { $("#tou").html("與服務器斷開了鏈接!") } $('#send').bind('click', function () { send(); }); function send() { if (websocket != null) { var message = document.getElementById('message').value; websocket.send(message); } else { alert('未與服務器鏈接.'); } } }); </script></head><body><div id="tou"> webSocket及時聊天Demo程序</div><div id="msg"></div><input type="text" id="message"><button type="button" id="send"> 發送</button></body></html>創建握手攔截器的類 HandInterceptor ，此類實現 HandshakeInterceptor接口。此類的功能有點類似于使用原始J2EE實現的@OnOpen注解package com._656463.demo.websocket.spring;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;import javax.servlet.http.HttpServletRequest;import java.util.Map;/** * 攔截器（握手） */public class HandInterceptor implements HandshakeInterceptor { @Override public boolean beforeHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler handler, Map<String, Object> map) throws Exception { if (request instanceof ServletServerHttpRequest) { HttpServletRequest req = ((ServletServerHttpRequest) request).getServletRequest(); String userName = "default-user"; // 使用userName區分WebSocketHandler，以便定向發送消息 // String userName = (String) // session.getAttribute("WEBSOCKET_USERNAME"); map.put("WEBSOCKET_USERNAME", userName); req.getSession().setAttribute("WEBSOCKET_USERNAME", userName); } return true; } @Override public void afterHandshake(ServerHttpRequest serverHttpRequest, ServerHttpResponse serverHttpResponse, WebSocketHandler webSocketHandler, Exception e) { }}創建一個類 WebSocketHander，實現 WebSocketHandler接口，此類的主要功能是消息處理中心，相當于使用原始J2EE API實現中的@OnMessage和@OnClose注解功能package com._656463.demo.websocket.spring;import org.springframework.web.socket.*;import java.io.IOException;import java.util.ArrayList;import java.util.List;/** * 消息處理中心 */public class WebSocketHander implements WebSocketHandler { private static final List<WebSocketSession> users = new ArrayList<WebSocketSession>(); /** * 初次鏈接成功執行 * * @param session * @throws Exception */ @Override public void afterConnectionEstablished(WebSocketSession session) throws Exception { System.out.println("鏈接成功......"); users.add(session); String userName = (String) session.getAttributes().get("WEBSOCKET_USERNAME"); if (userName != null) { //查詢未讀消息 int count = 5; session.sendMessage(new TextMessage(count + "")); } } /** * 接受消息處理消息 * * @param session * @param message * @throws Exception */ @Override public void handleMessage(WebSocketSession session, WebSocketMessage<?> message) throws Exception { sendMessageToUsers(new TextMessage(message.getPayload() + "")); } @Override public void handleTransportError(WebSocketSession session, Throwable throwable) throws Exception { if (session.isOpen()) { session.close(); } System.out.println("鏈接出錯，關閉鏈接......"); users.remove(session); } @Override public void afterConnectionClosed(WebSocketSession session, CloseStatus status) throws Exception { System.out.println("鏈接關閉......" + status.toString()); users.remove(session); } @Override public boolean supportsPartialMessages() { return false; } /** * 給所有在線用戶發送消息 * * @param message */ public void sendMessageToUsers(TextMessage message) { for (WebSocketSession user : users) { try { if (user.isOpen()) { user.sendMessage(message); } } catch (IOException e) { e.printStackTrace(); } } } /** * 給某個用戶發送消息 * * @param userName * @param message */ public void sendMessageToUser(String userName, TextMessage message) { for (WebSocketSession user : users) { if (user.getAttributes().get("WEBSOCKET_USERNAME").equals(userName)) { try { if (user.isOpen()) { user.sendMessage(message); } } catch (IOException e) { e.printStackTrace(); } break; } } }}有了握手攔截器和消息處理中心之后，要開啟WebSocket，讓他工作起來。開啟WebSocket有兩種方式，一種是基于注解的方式，二是基本XML配置的方式 1、基于注解的方式在springmvc的配置文件中，配置掃描包<context:component-scan base-package="com._656463.demo.websocket.spring"/>創建WebSocketConfig，開啟WebSocket，并注冊WebSocket的請求路徑package com._656463.demo.websocket.spring;import org.springframework.context.annotation.Configuration;import org.springframework.web.servlet.config.annotation.EnableWebMvc;import org.springframework.web.socket.config.annotation.EnableWebSocket;import org.springframework.web.socket.config.annotation.WebSocketConfigurer;import org.springframework.web.socket.config.annotation.WebSocketHandlerRegistry;/** * EnableWebSocket 開啟websocket * * @EnableWebMvc //這個標注可以不加，如果有加，要extends WebMvcConfigurerAdapter */@Configuration@EnableWebSocketpublic class WebSocketConfig implements WebSocketConfigurer { @Override public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) { // 支持websocket 的訪問鏈接 registry.addHandler(new WebSocketHander(), "/hello.htm") .addInterceptors(new HandInterceptor()); // 不支持websocket的訪問鏈接 registry.addHandler(new WebSocketHander(), "/sockjs/hello.htm") .addInterceptors(new HandInterceptor()) .withSockJS(); }}2、基于XML配置的方式在springmvc的配置文件中，通過websocket標簽配置WebSocket<bean id="websocket" class="com._656463.demo.websocket.spring.WebSocketHander"/><websocket:handlers> <websocket:mapping path="/hello.htm" handler="websocket" /> <websocket:handshake-interceptors> <bean class="com._656463.demo.websocket.spring.HandInterceptor"/> </websocket:handshake-interceptors></websocket:handlers>本次基于Springmvc的WebSocket實例就講完了，本實例是書生參考網絡整理的，希望對你有所幫助

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