spring websocket 使用@SendToUser
之前我们利用@SendTo在方法上进行注解，方法的返回值会被messageconverter转化并推送到消息代理器中，由消息代理器广播到订阅路径去
@MessageMapping("bar") //@MessageMapping接收客户端消息
@SendTo("/topic/brocast") //@SendTo广播消息出去
public String handle1(String msg) {
return msg;
}上面msg会被广播到”/topic/brocast”这个订阅路径中，只要客户端订阅了这条路径，不管是哪个用户，都会接收到消息
那么需求来了，如果我只是想简单的用websocket向服务器请求资源而已，然后服务器你就把资源给我就行了，别的用户就不用你广播推送了，简单点，就是我请求，你就推送给我。
spring websocket 可以使用@SendToUser做到这一点，在使用@SendToUser之前，我们需要明白以下几点：
1.spring webscoket通道的建立最开始还是源于http协议的第一次握手，握手成功之后，就打开了浏览器和服务器的webscoket通过，这时，httprequest中的登录授权信息即javax.security.Principal会被绑定到websocket的session中
2.spring webscoket能识别带”/user”的订阅路径并做出处理，例如，如果浏览器客户端，订阅了’/user/topic/greetings’这条路径，
stompClient.subscribe('/user/topic/greetings', function(data) {
//...
});就会被spring websocket利用UserDestinationMessageHandler进行转化成”/topic/greetings-usererbgz2rq”,”usererbgz2rq”中，user是关键字，erbgz2rq是sessionid，这样子就把用户和订阅路径唯一的匹配起来了
3.spring webscoket在使用@SendToUser广播消息的时候,
@MessageMapping("handle")
@SendToUser("/topic/greetings")
public String handle(String msg) {
//...
return msg;
}“/topic/greetings”会被UserDestinationMessageHandler转化成”/user/role1/topic/greetings”,role1是用户的登录帐号，这样子就把消息唯一的推送到请求者的订阅路径中去，这时候，如果一个帐号打开了多个浏览器窗口，也就是打开了多个websocket session通道，这时，spring webscoket默认会把消息推送到同一个帐号不同的session，你可以利用broadcast = false把避免推送到所有的session中
@MessageMapping("handle")
@SendToUser(value = "/topic/greetings",broadcast = false)
public String handle(String msg) {
//...
return name;
}下面来做个demo，首先是服务器要配置登录验证权限，这里利用tomcat的basic安全验证，在web.xml里面配置
<security-constraint>
<web-resource-collection>
<web-resource-name>protect resources web-resource-name>
<url-pattern>/*url-pattern>
<http-method>HEADhttp-method>
<http-method>GEThttp-method>
<http-method>POSThttp-method>
<http-method>PUThttp-method>
<http-method>DELETEhttp-method>
web-resource-collection>
<auth-constraint>
<role-name>role1role-name>
auth-constraint>
<user-data-constraint>
<transport-guarantee>NONEtransport-guarantee>
user-data-constraint>
security-constraint>
<login-config>
<auth-method>BASICauth-method>
login-config>
<security-role>
<description>Role1description>
<role-name>role1role-name>
security-role> role1是登录的角色名，其中验证信息可以在tomcat-users.xml里面配置
<role rolename="tomcat"/>
<role rolename="role1"/>
<user username="tomcat" password="tomcat" roles="tomcat"/>
<user username="both" password="tomcat" roles="tomcat,role1"/>
<user username="role1" password="tomcat" roles="role1"/>这里有俩个帐号，role1和both，角色都有role1，password都是tomcat，我们可以利用这俩个帐号在IE9和谷歌浏览器进行登录
然后服务器，我们分别使用@SendTo和@SendToUser进行广播推送和精准推送
首先我们注册下spring webscoket服务器
@Configuration
@EnableWebSocketMessageBroker
public class WebSocketMessageBrokerConfig implements WebSocketMessageBrokerConfigurer {
@Override
public void registerStompEndpoints(StompEndpointRegistry registry) {
//portfolio-stomp就是websocket的端点，客户端需要注册这个端点进行链接，withSockJS允许客户端利用sockjs进行浏览器兼容性处理
registry.addEndpoint("/portfolio-stomp").withSockJS();
}
@Override
public void configureMessageBroker(MessageBrokerRegistry registry) {
registry.enableSimpleBroker("/topic"); //设置服务器广播消息的基础路径
registry.setApplicationDestinationPrefixes("/app"); //设置客户端订阅消息的基础路径
registry.setPathMatcher(new AntPathMatcher(".")); //可以已“.”来分割路径，看看类级别的@messageMapping和方法级别的@messageMapping
}
@Override
public boolean configureMessageConverters(List messageConverters) {
return true;
}
@Override
public void configureWebSocketTransport(WebSocketTransportRegistration registry) {
// TODO Auto-generated method stub
registry.addDecoratorFactory(new MyWebSocketHandlerDecoratorFactory());
}
@Override
public void configureClientInboundChannel(ChannelRegistration registration) {
registration.setInterceptors(new MyChannelInterceptor());
}
@Override
public void configureClientOutboundChannel(ChannelRegistration registration) {
// TODO Auto-generated method stub
}
@Override
public void addArgumentResolvers(List argumentResolvers) {
// TODO Auto-generated method stub
}
@Override
public void addReturnValueHandlers(List returnValueHandlers) {
// TODO Auto-generated method stub
}
}
然后写下服务的的接收和发送
@Controller
@RequestMapping("/webSocket")
@MessageMapping("foo")
public class WebSocketController {
/**
* 精准推送
* @param msg
* @param principal
* @return
*/
@MessageMapping("handle1")
@SendToUser(value = "/topic/greetings1",broadcast = false)
public String handle1(String msg,Principal principal) {
return "精准推送，只推送到" + principal.getName();
}
/**
* 广播推送
* @param msg
* @param principal
* @return
*/
@MessageMapping("handle2")
@SendTo("topic/greetings2")
public String handle2(String msg,Principal principal) {
return "广播推送，所有用户都收得到";
}
}最后在浏览器客户端，我们利用sockjs和stomp.js链接并发送和订阅消息,其中在websocket.js代码就是这样子的
var socket = new SockJS('/whats/portfolio-stomp');
var stompClient = Stomp.over(socket);
stompClient.connect({}, function(frame) {
stompClient.subscribe('/user/topic/greetings1', function(data) {
$("#ret").text(data.body);
});
stompClient.subscribe('/topic/greetings2', function(data) {
$("#ret").text(data.body);
});
});
/**
* 精准推送
*/
document.getElementById("ws1").onclick = function() {
stompClient.send("/app/foo.handle2",{},{
msg : "精准推送"
});
}
/**
* 广播推送
*/
document.getElementById("ws").onclick = function() {
stompClient.send("/app/foo.handle1",{},{
msg : "广播推送"
});
}
jsp页面其实就是这样子的
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<html>
<head>
<meta charset="UTF-8">
<title>websockettitle>
head>
<body>
<h1>hello websocket client !!h1>
<button id = "ws">精准推送button>
<button id = "ws1">广播推送button>
<span id ="ret">span>
<script type="text/javascript" src="${pageContext.request.contextPath}/content/uilib/websocket/sockjs-1.0.3.js">script>
<script type="text/javascript" src="${pageContext.request.contextPath}/content/uilib/websocket/stomp.js">script>
<script type="text/javascript" src="${pageContext.request.contextPath}/content/js/websocket/websocket.js">script>
body>
html>到这里就完成了功能了
精准推送
广播推送
