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本文介绍如何使用websocket发送和请求消息
项目目录
依赖
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-websocket</artifactId>
</dependency>
DemoApplication
package com.springlearn.learn;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class DemoApplication {
public static void main(String[] args) {
SpringApplication.run(DemoApplication.class, args);
}
}
MessageModel
package com.springlearn.learn.model;
public class MessageModel {
private String name;
public String getName() {
return "测试成功" + name;
}
public void setName(String name) {
this.name = name;
}
}
WebConfig
package com.springlearn.learn.config;
import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.annotation.EnableScheduling;
import org.springframework.web.servlet.config.annotation.CorsRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
@Configuration
@EnableScheduling
public class WebConfig implements WebMvcConfigurer {
@Override
public void addCorsMappings(CorsRegistry registry) {
registry.addMapping("/**").allowedOrigins("*").allowedMethods("GET", "POST", "PUT", "DELETE").allowedOrigins("*")
.allowedHeaders("*");
}
}
WebSocketConfig
package com.springlearn.learn.config;
import com.springlearn.learn.Handler.HttpHandshakeInterceptor;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
import org.springframework.messaging.simp.config.MessageBrokerRegistry;
import org.springframework.web.socket.config.annotation.EnableWebSocketMessageBroker;
import org.springframework.web.socket.config.annotation.StompEndpointRegistry;
import org.springframework.web.socket.config.annotation.WebSocketMessageBrokerConfigurer;
@Configuration
@EnableWebSocketMessageBroker
public class WebSocketConfig implements WebSocketMessageBrokerConfigurer {
@Autowired
private HttpHandshakeInterceptor handshakeInterceptor; // 这个是自定义的拦截器
@Override
public void registerStompEndpoints(StompEndpointRegistry registry) {
registry.addEndpoint("/ws").setAllowedOrigins("*").withSockJS().setInterceptors(handshakeInterceptor);
}
@Override
public void configureMessageBroker(MessageBrokerRegistry registry) {
registry.setApplicationDestinationPrefixes("/app"); // 前端发送消息的前缀
registry.enableSimpleBroker("/topic"); // 前端接收后台消息和后台发送消息给前端的前缀
}
}
HttpHandshakeInterceptor
package com.springlearn.learn.Handler;
import java.util.Map;
import javax.servlet.http.HttpSession;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.http.server.ServletServerHttpRequest;
import org.springframework.stereotype.Component;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.server.HandshakeInterceptor;
@Component
public class HttpHandshakeInterceptor implements HandshakeInterceptor {
private static final Logger logger = LoggerFactory.getLogger(HttpHandshakeInterceptor.class);
@Override
public boolean beforeHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler wsHandler, Map<String, Object> attributes) throws Exception {
logger.info("Call beforeHandshake"); // 和out一样，输出语句，正式开发用这个多
if (request instanceof ServletServerHttpRequest) {
ServletServerHttpRequest servletRequest = (ServletServerHttpRequest) request;
HttpSession session = servletRequest.getServletRequest().getSession();
attributes.put("sessionId", session.getId());
}
return true;
}
public void afterHandshake(ServerHttpRequest request, ServerHttpResponse response, WebSocketHandler wsHandler,
Exception ex) {
logger.info("Call afterHandshake");
}
}
WebSocketEventListener
// 监听器，监听socket连接和短线
package com.springlearn.learn.listener;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.event.EventListener;
import org.springframework.messaging.simp.SimpMessageSendingOperations;
import org.springframework.messaging.simp.stomp.StompHeaderAccessor;
import org.springframework.stereotype.Component;
import org.springframework.web.socket.messaging.SessionConnectedEvent;
import org.springframework.web.socket.messaging.SessionDisconnectEvent;
@Component
public class WebSocketEventListener {
private static final Logger logger = LoggerFactory.getLogger(WebSocketEventListener.class);
@Autowired
private SimpMessageSendingOperations messagingTemplate;
@EventListener
public void handleWebSocketConnectListener(SessionConnectedEvent event) {
logger.info("Received a new web socket connection");
}
@EventListener
public void handleWebSocketDisconnectListener(SessionDisconnectEvent event) {
StompHeaderAccessor headerAccessor = StompHeaderAccessor.wrap(event.getMessage());
String username = (String) headerAccessor.getSessionAttributes().get("username");
if(username != null) {
logger.info("User Disconnected : " + username);
messagingTemplate.convertAndSend("/topic/getResponse", "User Disconnected : " + username);
}
}
}
WebSocketController
package com.springlearn.learn.controller;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import com.springlearn.learn.model.MessageModel;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.messaging.handler.annotation.MessageMapping;
import org.springframework.messaging.handler.annotation.Payload;
import org.springframework.messaging.handler.annotation.SendTo;
import org.springframework.messaging.simp.SimpMessageHeaderAccessor;
import org.springframework.messaging.simp.SimpMessageSendingOperations;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Controller;
@Controller
public class WebSocketController {
private static final DateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss sss");
@Autowired
private SimpMessageSendingOperations messagingTemplate;
@MessageMapping("/welcome")
@SendTo("/topic/getResponse")
public MessageModel sendMessage(@Payload MessageModel requestMessage, SimpMessageHeaderAccessor headerAccessor) {
headerAccessor.getSessionAttributes().put("username", requestMessage.getName());
MessageModel message = new MessageModel();
message.setName(requestMessage.getName());
return message;
}
@Scheduled(cron="* * * * * *" )
@SendTo("/topic/getResponse")
public Object callback() throws Exception {
Date now = new Date();
messagingTemplate.convertAndSend("/topic/getResponse", df.format(now));
return "callback";
}
}
前端测试
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
<script src="https://unpkg.com/axios/dist/axios.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/vue@2.5.17/dist/vue.js"></script>
<link rel="stylesheet" href="//unpkg.com/iview/dist/styles/iview.css">
<script src="//unpkg.com/iview/dist/iview.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/sockjs-client@1/dist/sockjs.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/stomp.js/2.3.3/stomp.min.js"></script>
</head>
<body>
<div id="app">
</div>
<script>
new Vue({
el: \'#app\',
mounted () {
var stompClient = null;
var socket = new SockJS(\'http://localhost:9001/ws\');
stompClient = Stomp.over(socket);
stompClient.connect(
{},
function (frame) {
stompClient.subscribe(\'/topic/getResponse\', function (payload) {
console.log(payload.body)
})
stompClient.send(
"/app/welcome",
{},
JSON.stringify({name: "yejiawei"})
)
},
function(error) {
connectingElement.textContent = \'Could not connect to WebSocket server. Please refresh this page to try again!\';
connectingElement.style.color = \'red\';
}
);
setTimeout(function() {
stompClient.send(
"/app/welcome",
{},
JSON.stringify({name: "来自前端的请求"})
)
}, 3000)
}
})
</script>
</body>
</html>