实现的版本jdk1.7.0_25, tomcat7.0.47.0, Tengine/2.1.1 (nginx/1.6.2), servlet3.0, spring4.2.2
使用maven导入版本3.0+的servlet包:
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
<version>3.0-alpha-1</version>
</dependency>
然后配置web.xml将版本的xsi配置在3.0以上:
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
version="3.0">
导入spring web socket包:
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-websocket</artifactId>
<version>4.2.2.RELEASE</version>
</dependency>
在spirng的DispatcherServlet的配置文件配置spring websocket handler,配置了建立连接的路径并通过allowed-origins参数来允许跨域访问:
<websocket:handlers allowed-origins="*">
<websocket:mapping path="/outer/notice/listen" handler="noticeMessageHandler"/>
<websocket:handshake-interceptors>
<bean class="com.j.socket.notice.NoticeMessageInterceptor"/>
</websocket:handshake-interceptors>
</websocket:handlers> <websocket:handlers allowed-origins="*">
<websocket:mapping path="/outer/notice/sockjs/listen" handler="noticeMessageHandler"/>
<websocket:handshake-interceptors>
<bean class="com.j.socket.notice.NoticeMessageInterceptor"/>
</websocket:handshake-interceptors>
<websocket:sockjs/>
</websocket:handlers>
配置handler class:
package com.j.socket.notice.NoticeMessageHandler; // import packages
@Component
public class NoticeMessageHandler implements WebSocketHandler { //存储当前所有的在线用户socket
//目前以userId为key,所以一个用户打开多个socket页面时只会在最新的页面推送消息
private static final Map<String, WebSocketSession> users = new HashMap<>(); //socket 连接常见时该方法被调用
@Override
public void afterConnectionEstablished(WebSocketSession webSocketSession) throws Exception {
//在socket Interceptor中设置的参数
String userId = webSocketSession.getAttributes().get("SOCKET_USER");
users.put(userId, webSocketSession);
} @Override
public void handleMessage(WebSocketSession webSocketSession, WebSocketMessage<?> webSocketMessage) throws Exception {
//前端发送消息时调用该方法
} //连接出错时
@Override
public void handleTransportError(WebSocketSession webSocketSession, Throwable throwable) throws Exception {
if (webSocketSession.isOpen()) {
webSocketSession.close();
}
String userId = webSocketSession.getAttributes().get("SOCKET_USER");
users.remove(userId);
} //连接关闭时
@Override
public void afterConnectionClosed(WebSocketSession webSocketSession, CloseStatus closeStatus) throws Exception {
String userId = webSocketSession.getAttributes().get("SOCKET_USER");
users.remove(userId);
} @Override
public boolean supportsPartialMessages() {
return false;
} //向某个用户发送消息
public void sendMessage(TextMessage message, String userId) {
WebSocketSession user = users.get(userId);
if (null != user && user.isOpen()) {
try {
user.sendMessage(message);
} catch (Exception e) {
}
}
} //批量向所有用户发送消息
public void sendMessage(TextMessage message) {
for (WebSocketSession user : users.values()) {
if (user.isOpen()) {
try {
user.sendMessage(message);
} catch (Exception e) {
}
}
}
}
}
配置拦截器，在websocket链接时从请求中获取用户数据，并存储起来。
public class NoticeMessageInterceptor implements HandshakeInterceptor {
@Override
public boolean beforeHandshake(ServerHttpRequest serverHttpRequest, ServerHttpResponse serverHttpResponse, WebSocketHandler webSocketHandler, Map<String, Object> map) throws Exception {
if (serverHttpRequest instanceof ServletServerHttpRequest) {
ServletServerHttpRequest request = (ServletServerHttpRequest) serverHttpRequest;
String userId = request.getServletRequest().getParameter("userId");
if (StringUtils.isNotBlank(userId)) {
map.put(Constants.SOCKET_USER, userId);
return true;
}
}
return false;
}
@Override
public void afterHandshake(ServerHttpRequest serverHttpRequest, ServerHttpResponse serverHttpResponse, WebSocketHandler webSocketHandler, Exception e) {
}
}
前端js代码，如果浏览器不支持socket时将使用sockJS 所以需要根据情况导入sockJS文件
var websocket;
if ('WebSocket' in window) {
websocket = new WebSocket("ws://yoururl.com/outer/notice/listen?userId="+ getUserId());
} else if ('MozWebSocket' in window) {
websocket = new MozWebSocket("ws://yoururl.com/outer/notice/listen?userId="+getUserId());
} else {
websocket = new SockJS("http://yoururl.com/outer/notice/sockjs/listen?userId="+getUserId());
}
websocket.onopen = function (evnt) {
};
var length = 0 ;
websocket.onmessage = function (evnt) {
console.log(length+=evnt.data.length);
};
websocket.onerror = function (evnt) {
console.log(evnt);
};
websocket.onclose = function (evnt) {
}
nginx相应配置
map $http_upgrade $connection_upgrade {
default upgrade;
'' close;
}
server {
...
location ~* /(outer/notice)|(outer/sockjs/notice)/ {
proxy_pass http://127.0.0.1:8084;
proxy_redirect off;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header Host $http_host;
proxy_set_header X-NginX-Proxy true;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "upgrade";
}