Spring WebSocket實現消息推送

第一步： 添加Spring WebSocket的依賴jar包

（注：這裏使用maven方式添加 手動添加的同窗請自行下載相應jar包放到lib目錄）

        <!-- 使用spring websocket依賴的jar包 -->
        <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>            

第二步：創建一個類實現WebSocketConfigurer接口

package com.quicksand.push;

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;


@Configuration
@EnableWebMvc
@EnableWebSocket
public class SpringWebSocketConfig extends WebMvcConfigurerAdapter implements WebSocketConfigurer {
    public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
        registry.addHandler(webSocketHandler(),"/websocket/socketServer.do").addInterceptors(new SpringWebSocketHandlerInterceptor());
        registry.addHandler(webSocketHandler(), "/sockjs/socketServer.do").addInterceptors(new SpringWebSocketHandlerInterceptor()).withSockJS();
    }
 
    @Bean
    public TextWebSocketHandler webSocketHandler(){
        return new SpringWebSocketHandler();
    }

}

 第三步：繼承WebSocketHandler對象。該對象提供了客戶端鏈接,關閉,錯誤,發送等方法,重寫這幾個方法便可實現自定義業務邏輯

package com.quicksand.push;

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;


public class SpringWebSocketHandler extends TextWebSocketHandler {
    private static final ArrayList<WebSocketSession> users;//這個會出現性能問題，最好用Map來存儲，key用userid
    private static Logger logger = Logger.getLogger(SpringWebSocketHandler.class);
    static {
        users = new ArrayList<WebSocketSession>();
    }
    
    public SpringWebSocketHandler() {
        // TODO Auto-generated constructor stub
    }

    /**
     * 鏈接成功時候，會觸發頁面上onopen方法
     */
    public void afterConnectionEstablished(WebSocketSession session) throws Exception {
        // TODO Auto-generated method stub
        System.out.println("connect to the websocket success......當前數量:"+users.size());
        users.add(session);
        //這塊會實現本身業務，好比，當用戶登陸後，會把離線消息推送給用戶
        //TextMessage returnMessage = new TextMessage("你將收到的離線");
        //session.sendMessage(returnMessage);
    }
    
    /**
     * 關閉鏈接時觸發
     */
    public void afterConnectionClosed(WebSocketSession session, CloseStatus closeStatus) throws Exception {
        logger.debug("websocket connection closed......");
        String username= (String) session.getAttributes().get("WEBSOCKET_USERNAME");
        System.out.println("用戶"+username+"已退出！");
        users.remove(session);
        System.out.println("剩餘在線用戶"+users.size());
    }

    /**
     * js調用websocket.send時候，會調用該方法
     */
    @Override    
    protected void handleTextMessage(WebSocketSession session, TextMessage message) throws Exception {
        super.handleTextMessage(session, message);
    }

    public void handleTransportError(WebSocketSession session, Throwable exception) throws Exception {
        if(session.isOpen()){session.close();}
        logger.debug("websocket connection closed......");
        users.remove(session);
    }

    public boolean supportsPartialMessages() {
        return false;
    }
    
    
    /**
     * 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;
            }
        }
    }
    
    /**
     * 給全部在線用戶發送消息
     *
     * @param message
     */
    public void sendMessageToUsers(TextMessage message) {
        for (WebSocketSession user : users) {
            try {
                if (user.isOpen()) {
                    user.sendMessage(message);
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

}

第四步：繼承HttpSessionHandshakeInterceptor對象。該對象做爲頁面鏈接websocket服務的攔截器,代碼以下：

package com.quicksand.push;
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;

/**
 * WebSocket攔截器
 * @author WANG
 *
 */
public class SpringWebSocketHandlerInterceptor extends HttpSessionHandshakeInterceptor {
    @Override
    public boolean beforeHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler wsHandler,
            Map<String, Object> attributes) throws Exception {
        // TODO Auto-generated method stub
        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區分WebSocketHandler，以便定向發送消息
                String userName = (String) session.getAttribute("SESSION_USERNAME");
                if (userName==null) {
                    userName="default-system";
                }
                attributes.put("WEBSOCKET_USERNAME",userName);
            }
        }
        return super.beforeHandshake(request, response, wsHandler, attributes);
        
    }
    
    @Override
    public void afterHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler wsHandler,
            Exception ex) {
        // TODO Auto-generated method stub
        super.afterHandshake(request, response, wsHandler, ex);
    }
}

第5步 讓SpringWebSocketConfig配置類隨spring容器啓動 spring文件中加入以下代碼：

<!-- websocket相關掃描，主要掃描：WebSocketConfig  若是前面配置能掃描到此類則能夠不加 -->
<context:component-scan base-package="com.quicksand.push"/>

 

 

-------------------------------------------------------------------------到這裏就算完成啦 下面準備測試-------------------------------------------------------------

1.定義一個控制器用來作鏈接標識和發送消息

package com.quicksand.controller;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.springframework.context.annotation.Bean;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.socket.TextMessage;

import com.quicksand.push.SpringWebSocketHandler;

@Controller
public class WebsocketController {
    @Bean//這個註解會從Spring容器拿出Bean
    public SpringWebSocketHandler infoHandler() {
        return new SpringWebSocketHandler();
    }

    @RequestMapping("/websocket/login")
    public ModelAndView login(HttpServletRequest request, HttpServletResponse response) throws Exception {
        String username = request.getParameter("username");
        System.out.println(username+"登陸");
        HttpSession session = request.getSession(false);
        session.setAttribute("SESSION_USERNAME", username);
        //response.sendRedirect("/quicksand/jsp/websocket.jsp");
        return new ModelAndView("websocket");
    }

    @RequestMapping("/websocket/send")
    @ResponseBody
    public String send(HttpServletRequest request) {
        String username = request.getParameter("username");
        infoHandler().sendMessageToUser(username, new TextMessage("你好，測試！！！！"));
        return null;
    }
}

 

2.創建登陸頁面

<%@ 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>
<body>
<h2>Hello World!</h2>
<body>
    <!-- ship是個人項目名-->
    <form action="websocket/login.do">
        登陸名：<input type="text" name="username"/>
        <input type="submit" value="登陸"/>
    </form>
</body>
</body>
</html>

 

3.創建發消息頁面

<%@ 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>Insert title here</title>
</head>
<body>
<script type="text/javascript" src="http://cdn.bootcss.com/jquery/3.1.0/jquery.min.js"></script>
<script type="text/javascript" src="http://cdn.bootcss.com/sockjs-client/1.1.1/sockjs.js"></script>
<script type="text/javascript">
    var websocket = null;
    if ('WebSocket' in window) {
        websocket = new WebSocket("ws://localhost:8080/quicksand/websocket/socketServer.do");
    } 
    else if ('MozWebSocket' in window) {
        websocket = new MozWebSocket("ws://localhost:8080/quicksand/websocket/socketServer.do");
    } 
    else {
        websocket = new SockJS("http://localhost:8080/quicksand/sockjs/socketServer.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);//調用後臺handleTextMessage方法
            alert("發送成功!");  
        } else {  
            alert("鏈接失敗!");  
        }  
    }

　　　window.close=function()
　　　{
　　　　　websocket.onclose();
　　　}

</script>
請輸入：<textarea rows="5" cols="10" id="inputMsg" name="inputMsg"></textarea>
<button onclick="doSend();">發送</button>
</body>
</html>

 

測試結果以下圖：

 

 

文章參考：http://www.myexception.cn/web/1775480.html