spring 搭建 websocket

最新推荐文章于 2024-10-28 15:19:00 发布

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最新推荐文章于 2024-10-28 15:19:00 发布

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CC 4.0 BY-SA版权

文章标签：网络 java ui

原文链接：https://my.oschina.net/u/2528821/blog/1186743

本文介绍了一个基于Spring框架的WebSocket聊天应用实例，详细展示了如何配置Maven依赖、设置web.xml及springmvc-servlet.xml文件，同时提供了控制器类IndexController的具体实现，并深入解析了WebSocket配置类WebsocketConfig的工作原理。

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maven依赖

pool.xml

<?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/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>springws</groupId>
    <artifactId>springws</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>4.3.9.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>4.3.9.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-websocket</artifactId>
            <version>4.3.9.RELEASE</version>
        </dependency>

    </dependencies>

</project>

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
         version="3.1">

    <!--configure the setting of springmvcDispatcherServlet and configure the mapping-->
    <servlet>
        <servlet-name>springmvc</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>/WEB-INF/springmvc-servlet.xml</param-value>
        </init-param>
        <!-- <load-on-startup>1</load-on-startup> -->
    </servlet>

    <servlet-mapping>
        <servlet-name>springmvc</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

</web-app>

springmvc-servlet.xml

<?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"
       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">

    <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
        <property name="messageConverters">
            <list>
                <ref bean="stringHttpMessageConverter" />
            </list>
        </property>
    </bean>


    <!-- scan the package and the sub package -->
    <context:component-scan base-package="com.chen"/>

    <!-- don't handle the static resource -->
    <mvc:default-servlet-handler />

    <!-- if you use annotation you must configure following setting -->
    <mvc:annotation-driven />

    <!-- configure the InternalResourceViewResolver -->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"
          id="internalResourceViewResolver">
        <!-- 前缀 -->
        <property name="prefix" value="/WEB-INF/view/" />
        <!-- 后缀 -->
        <property name="suffix" value=".jsp" />
    </bean>


    <bean id="stringHttpMessageConverter"
          class="org.springframework.http.converter.StringHttpMessageConverter">
        <property name="supportedMediaTypes">
            <list>
                <value>text/plain;charset=UTF-8</value>
            </list>
        </property>
    </bean>
</beans>

显示的控制器：

indexController.java

package com.chen;

import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.RequestMapping;

/**
 * Created by yuerwang on 2017/7/6.
 */

@Controller
@RequestMapping("/Index")
public class IndexController {
    @RequestMapping("/index")
    public void index(ModelMap mp){
         mp.put("chen",123);
    }

}

显示页面

index.jsp

<%--
  Created by IntelliJ IDEA.
  Date: 2017/7/6
  Time: 14:39
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
  <title>测试</title>
  <script src="http://libs.baidu.com/jquery/2.0.0/jquery.min.js"></script>
</head>
<body>
${chen}
<input type="text" id="inputMsg" placeholder="请输入内容"/>
<button onclick="send()">提交</button>
</body>

<script type="text/javascript">


  var wsUri ="ws://localhost:8080/websocket/chatMessageServer.do";
  var output;

  function init() {
     testWebSocket();
  }

  function testWebSocket() {
    websocket = new WebSocket(wsUri);
    websocket.onopen = function(evt) {
      onOpen(evt)
    };
    websocket.onclose = function(evt) {
      onClose(evt)
    };
    websocket.onmessage = function(evt) {
      onMessage(evt)
    };
    websocket.onerror = function(evt) {
      onError(evt)
    };
  }

  function send(){
    if (websocket.readyState == websocket.OPEN) {
      var msg = document.getElementById("inputMsg").value;
      websocket.send(msg);//调用后台handleTextMessage方法
    }else{
      alert("没有链接")
    }
  }

  function onOpen(evt) {
    writeToScreen("CONNECTED");
    doSend("WebSocket rocks");
  }

  function onClose(evt) {
    writeToScreen("DISCONNECTED");
  }

  function onMessage(evt) {
    writeToScreen('<span style="color: blue;">RESPONSE: '+ evt.data+'</span>');
    //websocket.close();
  }

  function onError(evt) {
    writeToScreen('<span style="color: red;">ERROR:</span> '+ evt.data);
  }

  function doSend(message) {
    writeToScreen("SENT: " + message);
    websocket.send(message);
  }

  function writeToScreen(message) {
    var pre = document.createElement("p");
    pre.style.wordWrap = "break-word";
    pre.innerHTML = message;
    console.log(message)
  }

  window.addEventListener("load", init, false);

</script>
</html>

处理websocket

WebsocketConfig.java

package com.chen.conf;

import org.springframework.context.annotation.Bean;
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;
import org.springframework.web.socket.handler.TextWebSocketHandler;

@Configuration
@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();
    }

}

ChatHandshakeInterceptor.java

package com.chen.conf;

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 org.springframework.web.socket.server.support.HttpSessionHandshakeInterceptor;


import javax.servlet.http.HttpSession;
import java.util.Map;

/**
 * Created by yuerwang on 2017/7/6.
 */
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);
    }
}

ChatMessageHandler.java(主要处理逻辑)

package com.chen.conf;

import java.io.IOException;
import java.util.ArrayList;

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;



/**
 * Created by yuerwang on 2017/7/6.
 */
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
    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("你将收到的消息");
        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 {
        for (WebSocketSession user:users){
            System.out.println(user);
        }
        System.out.println("发送的是："+message);
        //回复群体消息
        //sendMessageToUsers(new TextMessage("全体消息："+message.getPayload()));
        //回复发送者消息
        session.sendMessage(message);
        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();
        }
        users.remove(session);
    }

    @Override
    public void afterConnectionClosed(WebSocketSession session, CloseStatus closeStatus) throws Exception {
        users.remove(session);
    }

    @Override
    public boolean supportsPartialMessages() {
        return false;
    }

}

Constants.java

package com.chen.conf;

public class Constants {
   public static final String WEBSOCKET_USERNAME = "ws_user";  
   public static final String SESSION_USERNAME = "se_user";
}

转载于:https://my.oschina.net/u/2528821/blog/1186743