spring+websocket的整合实例(超详细，可使用)

定义：

WebSocket协议是基于TCP的一种新的网络协议。它实现了浏览器与服务器全双工(full-duplex)通信——允许服务器主动发送信息给客户端

上面是百度官网的介绍，我主要使用websocket的目的是为了，能让服务器能够主动推送消息给浏览器，而不是之前通过ajax或者长轮循不断触发服务器。

我通过学习整合了一个简单可用通讯的实例。好了，废话不多说，直接上内容。

整合步骤：

由于我用的maven项目，所以先通过pom.xml进行引包。

**第一步：**pom.xml引包

在这里需要注意2点：1、spring相关的jar包必须是版本4以上的 2、websoket引入的jar包版本号和spring的版本号要一直，如果不一致的话回出现：NoClassDefFoundError: org/springframework/web/cors/CorsProcessor，这样框架异常。

添加的spring的支持包：

<!-- 添加Spring支持 -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>4.2.4.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-beans</artifactId>
<version>4.2.4.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-tx</artifactId>
<version>4.2.4.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>4.2.4.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context-support</artifactId>
<version>4.2.4.RELEASE</version>
</dependency>

<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>4.2.4.RELEASE</version>
</dependency>

<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>4.2.4.RELEASE</version>
</dependency>

<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aop</artifactId>
<version>4.2.4.RELEASE</version>
</dependency>

<dependency>
<groupId>commons-lang</groupId>
<artifactId>commons-lang</artifactId>
<version>2.6</version>
<scope>provided</scope>
</dependency>

<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aspects</artifactId>
<version>4.2.4.RELEASE</version>
</dependency>

<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>4.2.4.RELEASE</version>
</dependency>

添加websocket的jar包

<!-- 添加对websocket的支持 -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-orm</artifactId>
<version>4.2.4.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>4.2.4.RELEASE</version>
</dependency>

<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-websocket</artifactId>
<version>4.2.4.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-messaging</artifactId>
<version>4.2.4.RELEASE</version>
</dependency>

第二步：配置spring-websocket.xml文件

这里注意的是：xsi:schemaLocation属性后面俩行一定要有。

<?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:websocket="http://www.springframework.org/schema/websocket"
xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd http://www.springframework.org/schema/websocket http://www.springframework.org/schema/websocket/spring-websocket-4.0.xsd">

<bean id="websocket" class="com.web.common.util.websocket.WebSocketHander" />

<websocket:handlers>
<websocket:mapping path="/echo" handler="websocket" />
<websocket:handshake-interceptors>
<bean class="com.web.common.util.websocket.HandshakeInterceptor" />
</websocket:handshake-interceptors>
</websocket:handlers>

</beans>

在applicationContext.xml中引入spring-websocket.xml文件

<!-- 引入websocket -->
<import resource="spring-websocket.xml"/>

在web.xml中引入applicationContext.xml

<!-- Spring配置文件 -->
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:applicationContext.xml</param-value>
</context-param>

第三步：编写代码

package com.web.common.util.websocket;

import org.apache.shiro.session.Session;
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 javax.servlet.http.HttpServletRequest;

import java.util.Map;

/**
* 拦截器
*
* @author wangguan,
* @date 2017年11月22日 上午9:33:46,
* @version argType
*/

public class HandshakeInterceptor implements org.springframework.web.socket.server.HandshakeInterceptor{
Session session;
// 初次握手访问前
public boolean beforeHandshake(ServerHttpRequest request, ServerHttpResponse serverHttpResponse,
WebSocketHandler webSocketHandler, Map<String, Object> map) throws Exception {
if (request instanceof ServletServerHttpRequest) {
HttpServletRequest servletRequest = ((ServletServerHttpRequest) request).getServletRequest();
String sessionId=servletRequest.getSession().getId();//获取浏览器的sessionid
String username=(String)servletRequest.getSession().getAttribute("name");
System.out.println("获取session里面的name-------------------"+username);
// 使用userName区分WebSocketHandler，以便定向发送消息
/* String userName = (String)*/
//session.getAttribute("WEBSOCKET_USERNAME");
map.put("WEBSOCKET_USERNAME", username);
servletRequest.getSession().setAttribute("WEBSOCKET_USERNAME", username);
}
return true;
}

// 初次握手访问后
public void afterHandshake(ServerHttpRequest serverHttpRequest, ServerHttpResponse serverHttpResponse,
WebSocketHandler webSocketHandler, Exception e) {

}
}

WebSocketHander 实现WebSocketHandler

package com.web.common.util.websocket;

import org.apache.log4j.Logger;
import org.springframework.web.socket.*;

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

public class WebSocketHander implements WebSocketHandler {

private static final Logger logger = Logger.getLogger(WebSocketHander.class);

private static final ArrayList<WebSocketSe
a859
ssion> users = new ArrayList<WebSocketSession>();

private String userName="";

// 初次链接成功执行
public void afterConnectionEstablished(WebSocketSession session) throws Exception {
logger.debug("链接成功......");
users.add(session);
userName = (String) session.getAttributes().get("WEBSOCKET_USERNAME");
System.out.println("第一次连接获取的id--"+userName);
if (userName != null) {
// 查询未读消息
int count = 5;
session.sendMessage(new TextMessage(count + ""));
}
}

// 接受消息处理消息
public void handleMessage(WebSocketSession webSocketSession, WebSocketMessage<?> webSocketMessage)
throws Exception {
//sendMessageToUsers(new TextMessage(webSocketMessage.getPayload() + ""));
sendMessageToUser(userName, new TextMessage(webSocketMessage.getPayload() + ""));

}

public void handleTransportError(WebSocketSession webSocketSession, Throwable throwable) throws Exception {
if (webSocketSession.isOpen()) {
webSocketSession.close();
}
logger.debug("链接出错，关闭链接......");
users.remove(webSocketSession);
}

public void afterConnectionClosed(WebSocketSession webSocketSession, CloseStatus closeStatus) throws Exception {
logger.debug("链接关闭......" + closeStatus.toString());
users.remove(webSocketSession);
}

public boolean supportsPartialMessages() {
return false;
}

/**
* 给所有在线用户发送消息
*
* @param message
*/
public void sendMessageToUsers(TextMessage message) {
for (WebSocketSession user : users) {
System.out.println(user.getAttributes().get("WEBSOCKET_USERNAME"));
try {
if (user.isOpen()) {
user.sendMessage(message);
}
} catch (IOException e) {
e.printStackTrace();
}
}
}

/**
* 给某个用户发送消息，模拟给admin发信息
*
* @param userName
* @param message
*/
public void sendMessageToUser(String userName, TextMessage message) {
for (WebSocketSession user : users) {
System.out.println("从session里面获取的id"+user.getAttributes().get("WEBSOCKET_USERNAME"));
if (user.getAttributes().get("WEBSOCKET_USERNAME").equals("admin")) {
try {
if (user.isOpen()) {
user.sendMessage(message);
}
} catch (IOException e) {
e.printStackTrace();
}
break;
}
}
}
}

启动项目：

我做了一个模拟，用俩个用户登录，让其中一个用户发消息，另外一个用户接受到消息。所以在我HandshakeInterceptor 用session去用户的登录名用户定向发送消息。(可以自己写一个login的controller,然后把loginName存入的session中，这样HandshakeInterceptor 中才能取到name值。)

我分别用360浏览器和火狐浏览器，模拟俩个登录用户，admin和tea



由tea向admin发送消息