1、引入jar，spring-websocket-starter

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

2、配置websocket config

import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.config.annotation.EnableWebSocket;
import org.springframework.web.socket.config.annotation.WebSocketConfigurer;
import org.springframework.web.socket.config.annotation.WebSocketHandlerRegistry;
 
@Configuration
@EnableWebSocket
public class WebSocketConfig implements WebSocketConfigurer {
    @Override
    public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
        registry.addHandler(myHandler(), "/myEndpoint").setAllowedOrigins("*");
    }
 
    public WebSocketHandler myHandler() {
        return new MyWebSocketHandler();
    }
}

3、使用实现websocket handler

import org.springframework.web.socket.TextMessage;
import org.springframework.web.socket.WebSocketSession;
import org.springframework.web.socket.handler.TextWebSocketHandler;
 
public class MyWebSocketHandler extends TextWebSocketHandler {
    @Override
    public void handleTextMessage(WebSocketSession session, TextMessage message) throws Exception {
        System.out.println("Received: " + message.getPayload());
        session.sendMessage(new TextMessage("Hello from server"));
    }
}

4、前端使用

<script>
    var socket = new WebSocket("ws://localhost:8080/myEndpoint");
    socket.onmessage = function(event) {
        console.log('Received from server:', event.data);
    };
    socket.onopen = function() {
        socket.send('Hello Server');
    };
</script>