websocket为浏览器为服务器提供了双工异步通信的功能,即浏览器可以向服务器发送消息,服务器也可以向浏览器发送消息。websocket需要浏览器的支持(ie10+、chrome 13+、firefox 6+)。
websocket是通过一个socket来实现双工异步通信功能,但是直接使用websocket会比较麻烦,我们使用它的子协议stomp,它是一个更高级的协议,stomp使用一个基于帧的格式来定义消息,与http的request和response类似。
实战(新建spring boot项目,选择thymeleaf和websocket)
1、广播式
广播式即服务端有消息时,会将消息发给所有连接了当前endpoint的浏览器。
① 配置websocket,需要再配置类上使用@EnableWebSocketMessageBroker开启websocket,并通过AbstractWebSocketMessageBrokerConfigurer类。
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 | package com.example.demo; import org.springframework.context.annotation.Configuration; import org.springframework.messaging.simp.config.MessageBrokerRegistry; import org.springframework.web.socket.config.annotation.AbstractWebSocketMessageBrokerConfigurer; import org.springframework.web.socket.config.annotation.EnableWebSocketMessageBroker; import org.springframework.web.socket.config.annotation.StompEndpointRegistry; import org.springframework.web.socket.config.annotation.WebSocketMessageBrokerConfigurer; /** * Created by xingzhuipingye on 2017/5/25. */ @Configuration //开启stomp协议来传输基于代理message broker的消息 @EnableWebSocketMessageBroker public class WebSocketConfig extends AbstractWebSocketMessageBrokerConfigurer { @Override //注册stomp协议节点 endpoint public void registerStompEndpoints(StompEndpointRegistry stompEndpointRegistry) { //注册一个endpoint 并指定是哟个socketjs stompEndpointRegistry.addEndpoint( "/endpointWisely" ).withSockJS(); } @Override //配置消息代理 public void configureMessageBroker(MessageBrokerRegistry registry) { //广播式配置一个topic的消息代理 registry.enableSimpleBroker( "/topic" ); } } |
② 浏览器向服务器发送的类
1 2 3 4 5 6 7 8 9 10 11 12 13 | package com.example.demo; /** * Created by xingzhuipingye on 2017/5/25. */ //浏览器向服务器发送消息用此类接受 public class WiselyMessage { private String name; public String getName() { return name; } } |
③ 服务器向浏览器发送此类的消息
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 | package com.example.demo; /** * Created by xingzhuipingye on 2017/5/25. */ public class WiselyResponse { private String responseMessage; public WiselyResponse(String responseMessage) { this .responseMessage = responseMessage; } public String getResponseMessage() { return responseMessage; } } |
④ 控制器
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 | package com.example.demo; import org.springframework.messaging.handler.annotation.MessageMapping; import org.springframework.messaging.handler.annotation.SendTo; import org.springframework.stereotype.Controller; /** * Created by xingzhuipingye on 2017/5/25. */ @Controller public class WsController { //当浏览器向服务器发送请求的时候通过@MessageMapping 映射/welcome 这个地址 类似 RequestMapping @MessageMapping ( "/welcome" ) //当服务器有消息的时候,会对订阅了@SendTo中的路径浏览器发送消息 @SendTo ( "/topic/getResponse" ) public WiselyResponse say(WiselyMessage wiselyMessage) throws InterruptedException { Thread.sleep( 3000 ); return new WiselyResponse( "Welcome," + wiselyMessage.getName()); } } |
⑤ 页面
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 | <! DOCTYPE html> < html lang="cn" xml:th="http://www.thymeleaf.org" xmlns:link="http://www.w3.org/1999/xhtml" xmlns:th="http://www.w3.org/1999/xhtml"> < head > < meta charset="UTF-8"/> < title >Title</ title > < script src="http://cdn.bootcss.com/sockjs-client/1.1.4/sockjs.min.js"></ script > < script src="https://cdn.bootcss.com/stomp.js/2.3.3/stomp.js"></ script > < script src="https://cdn.bootcss.com/jquery/3.2.1/jquery.min.js"></ script > </ head > < body onload="disconnect()"> < div > < button id="connect" onclick="connect()">连接</ button > < button id="disconnect" disabled="disabled" onclick="disconnect()">断开连接</ button > </ div > < div id="conversationDiv"> < label >输入你的名字</ label > < input type="text" id="name"/> < button id="sendName" onclick="sendName()">发送</ button > < p id="response"></ p > </ div > </ body > < script > var stompClient = null; function setConnected(connected) { document.getElementById("connect").disabled = connected; document.getElementById('disconnect').disabled = !connected; document.getElementById('conversationDiv').style.visibility = connected ? 'visible' : 'hidden'; $('#response').html(); } function connect() { var socket = new SockJS('/endpointWisely'); stompClient = Stomp.over(socket); stompClient.connect({},function (frame) { setConnected(true); console.log('connected'+ frame); stompClient.subscribe('/topic/getResponse',function (response) { showResponse(JSON.parse(response.body).responseMessage); }); }); } function disconnect() { if(stompClient!=null){ stompClient.disconnect(); } setConnected(false); console.log('disconnected') } function sendName() { var name = $('#name').val(); stompClient.send('/welcome',{},JSON.stringify({'name':name})); } function showResponse(message) { var response = $('#response'); response.html(message); } </ script > </ html > |
打开三个浏览器分别输入名字测试
当一个浏览器发送一个消息到服务器端的时候,其他浏览器也能收到从服务器端发送来的消息。