1.Tomcat實(shí)現(xiàn)websocket方法
1.1 新建JavaWeb測(cè)試項(xiàng)目
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1.2 在pom.xml中添加Jar包依賴
<dependency>
<groupId>javax</groupId>
<artifactId>javaee-api</artifactId>
<version>7.0</version>
<scope>provided</scope>
</dependency>
2. Spring整合websocket方法(基于Spring MVC 框架)
2.1 WebSocketConfig.java
- 這個(gè)類是配置類，所以需要在spring mvc配置文件中加入對(duì)這個(gè)類的掃描，第一個(gè)addHandler是對(duì)正常連接的配置，第二個(gè)是如果瀏覽器不支持websocket，使用socketjs模擬websocket的連接。
package com.websocket;
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(),"/webSocketServer").addInterceptors(new ChatHandshakeInterceptor());
registry.addHandler(chatMessageHandler(), "/sockjs/webSocketServer").addInterceptors(new ChatHandshakeInterceptor()).withSockJS();
}
@Bean
public TextWebSocketHandler chatMessageHandler(){
return new ChatMessageHandler();
}
}
2.2 ChatHandshakeInterceptor.java
- 這個(gè)類的作用就是在連接成功前和成功后增加一些額外的功能，Constants.java類是一個(gè)工具類，兩個(gè)常量。
package com.websocket;
import java.util.Map;
import org.apache.shiro.SecurityUtils;
import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.server.support.HttpSessionHandshakeInterceptor;
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區(qū)分WebSocketHandler，以便定向發(fā)送消息 String userName =
* (String) session.getAttribute(Constants.SESSION_USERNAME); if
* (userName==null) { userName="default-system"; }
* attributes.put(Constants.WEBSOCKET_USERNAME,userName);
*
* } }
*/
//使用userName區(qū)分WebSocketHandler，以便定向發(fā)送消息(使用shiro獲取session,或是使用上面的方式)
String userName = (String) SecurityUtils.getSubject().getSession().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);
}
}
2.3 ChatMessageHandler.java
- 這個(gè)類是對(duì)消息的一些處理，比如是發(fā)給一個(gè)人，還是發(fā)給所有人，并且前端連接時(shí)觸發(fā)的一些動(dòng)作.
package com.websocket;
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 ChatMessageHandler extends TextWebSocketHandler {
private static final ArrayList<WebSocketSession> users;// 這個(gè)會(huì)出現(xiàn)性能問(wèn)題，最好用Map來(lái)存儲(chǔ)，key用userid
private static Logger logger = Logger.getLogger(ChatMessageHandler.class);
static {
users = new ArrayList<WebSocketSession>();
}
/**
* 連接成功時(shí)候，會(huì)觸發(fā)UI上onopen方法
*/
@Override
public void afterConnectionEstablished(WebSocketSession session) throws Exception {
System.out.println("connect to the websocket success......");
users.add(session);
// 這塊會(huì)實(shí)現(xiàn)自己業(yè)務(wù)，比如，當(dāng)用戶登錄后，會(huì)把離線消息推送給用戶
// TextMessage returnMessage = new TextMessage("你將收到的離線");
// session.sendMessage(returnMessage);
}
/**
* 在UI在用js調(diào)用websocket.send()時(shí)候，會(huì)調(diào)用該方法
*/
@Override
protected void handleTextMessage(WebSocketSession session, TextMessage message) throws Exception {
sendMessageToUsers(message);
//super.handleTextMessage(session, message);
}
/**
* 給某個(gè)用戶發(fā)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;
}
}
}
/**
* 給所有在線用戶發(fā)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;
}
}
2.4 spring-mvc.xml
- 正常的配置文件，同時(shí)需要增加對(duì)WebSocketConfig.java類的掃描，并且增加
xmlns:websocket="http://www.springframework.org/schema/websocket"
http://www.springframework.org/schema/websocket
<a target="_blank" >http://www.springframework.org/schema/websocket/spring-websocket-4.1.xsd</a>
2.5 客戶端
<script type="text/javascript"
src="http://localhost:8080/Bank/js/sockjs-0.3.min.js"></script>
<script>
var websocket;
if ('WebSocket' in window) {
websocket = new WebSocket("ws://" + document.location.host + "/Bank/webSocketServer");
} else if ('MozWebSocket' in window) {
websocket = new MozWebSocket("ws://" + document.location.host + "/Bank/webSocketServer");
} else {
websocket = new SockJS("http://" + document.location.host + "/Bank/sockjs/webSocketServer");
}
websocket.onopen = function(evnt) {};
websocket.onmessage = function(evnt) {
$("#test").html("(<font color='red'>" + evnt.data + "</font>)")
};
websocket.onerror = function(evnt) {};
websocket.onclose = function(evnt) {}
$('#btn').on('click', function() {
if (websocket.readyState == websocket.OPEN) {
var msg = $('#id').val();
//調(diào)用后臺(tái)handleTextMessage方法
websocket.send(msg);
} else {
alert("連接失敗!");
}
});
</script>
