if("WebSocket" in window) {
	var ws = new WebSocket("ws://127.0.0.1:8090/api/webSocket");
	ws.onopen = function() {
		ws.send("前端向后台发送的数据...");
	}
	ws.onmessage = function(evt) {
		// evt.data后台向前端发送的数据...
	}
	ws.onclose = function() {
		// 关闭连接
	}
} else {
	// 浏览器不支持WebSocket
}

import lombok.extern.slf4j.Slf4j;
import org.springframework.context.annotation.Bean;
import org.springframework.stereotype.Component;
import org.springframework.web.socket.server.standard.ServerEndpointExporter;

import javax.websocket.OnClose;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.server.ServerEndpoint;
import java.io.IOException;
import java.util.concurrent.CopyOnWriteArraySet;


@ServerEndpoint("/api/webSocket")
@Component
@Slf4j
public class WebSocket {

    private Session session;
    private static CopyOnWriteArraySet<WebSocket> webSockets = new CopyOnWriteArraySet<>();

    /**
     * 新建webSocket配置类
     *
     * @return
     */
    @Bean
    public ServerEndpointExporter serverEndpointExporter() {
        return new ServerEndpointExporter();
    }

    /**
     * 建立连接
     *
     * @param session
     */
    @OnOpen
    public void onOpen(Session session) {
        this.session = session;
        webSockets.add(this);
        log.info("【新建连接】，连接总数:{}", webSockets.size());
    }

    /**
     * 断开连接
     */
    @OnClose
    public void onClose() {
        webSockets.remove(this);
        log.info("【断开连接】，连接总数:{}", webSockets.size());
    }

    /**
     * 接收到信息
     *
     * @param message
     */
    @OnMessage
    public void onMessage(String message) {
        log.info("【收到】，客户端的信息:{}，连接总数:{}", message, webSockets.size());
    }

    /**
     * 发送消息
     *
     * @param message
     */
    public void sendMessage(String message) {
        log.info("【广播发送】，信息:{}，总连接数:{}", message, webSockets.size());
        for (WebSocket webSocket : webSockets) {
            try {
                webSocket.session.getBasicRemote().sendText(message);
            } catch (IOException e) {
                log.info("【广播发送】，信息异常:{}", e.fillInStackTrace());
            }
        }
    }

}