介绍

WebSocket是基于TCP的一种新的网络协议，实现了浏览器域服务器全双工通信——浏览器和服务器只需要完成一次握手，两者直接就可以创建持久性的连接，并进行双向数据传输。

Http协议和WebSocket协议对比：

* HTTP是短连接

* WebSocket是长连接

* HTTP通信是单向的，基于请求响应模式

* WebSocket支持双向通信

步骤

        <dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-websocket</artifactId></dependency>

config配置

package com.sky.config;import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.server.standard.ServerEndpointExporter;/*** WebSocket配置类，用于注册WebSocket的Bean*/
@Configuration
public class WebSocketConfiguration {@Beanpublic ServerEndpointExporter serverEndpointExporter() {return new ServerEndpointExporter();}}

package com.sky.task;import com.sky.websocket.WebSocketServer;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;@Component
public class WebSocketTask {@Autowiredprivate WebSocketServer webSocketServer;/*** 通过WebSocket每隔5秒向客户端发送消息*/@Scheduled(cron = "0/5 * * * * ?")public void sendMessageToClient() {webSocketServer.sendToAllClient("这是来自服务端的消息：" + DateTimeFormatter.ofPattern("HH:mm:ss").format(LocalDateTime.now()));}
}