SpringBootでWebSocketを使う

プロセス全体は次のとおりです.
1.依存の追加
2.注入サーバEndpointExporter
3.WebSocketインタフェースの作成
4.ビジネスで呼び出す
5.フロントエンドjs
以下から開始します.
1.依存の追加

	org.springframework.boot
	spring-boot-starter-websocket

2.注入サーバEndpointExporter

import org.springframework.context.annotation.Bean;
import org.springframework.stereotype.Component;
import org.springframework.web.socket.server.standard.ServerEndpointExporter;


@Component
public class WebSocketConfig {

    @Bean
    public ServerEndpointExporter serverEndpointExporter(){
        return new ServerEndpointExporter();
    }

}

3.WebSocketインタフェースの作成

import lombok.extern.apachecommons.CommonsLog;
import org.springframework.stereotype.Component;

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;


@Component
@CommonsLog
@ServerEndpoint("/websocket")
public class WebSocket {

    private Session session;

    private static CopyOnWriteArraySet webSocketSet = new CopyOnWriteArraySet<>();

    @OnOpen
    public void onOpen(Session session){
        this.session = session;
        webSocketSet.add(this);
        log.info("      ，     ：" + webSocketSet.size());
    }

    @OnClose
    public void onClose(){
        webSocketSet.remove(this);
        log.info("       ，     ：" + webSocketSet.size());
    }

    @OnMessage
    public void onMessage(String message){
        log.info("      ：" + message);
    }

    public void sendMessage(String message){
        for(WebSocket webSocket : webSocketSet){
            log.info("    ：" + message);
            try {
                webSocket.session.getBasicRemote().sendText(message);
            } catch (IOException e){
                log.error(e.fillInStackTrace());
            }

        }
    }


}

4.ビジネスで呼び出す

@Autowired
private WebSocket webSocket;

...

webSocket.sendMessage("new-order");

5.フロントエンドjs

    //             
    var myAuto = document.getElementById('order_audio');
    var websocket = null;
    if('WebSocket' in window){
        websocket = new WebSocket('wss://xxxx.com/websocket');
    } else {
        alert('      websocket');
    }

    //     ，      
    var heartCheck = {
        timeout: 60000,//60s
        timeoutObj: null,
        reset: function(){
            clearInterval(this.timeoutObj);
            this.start();
        },
        start: function(){
            this.timeoutObj = setInterval(function(){
                if(websocket.readyState==1){
                    websocket.send("HeartBeat");
                }
            }, this.timeout)
        }
    };

    websocket.onopen = function (ev) {
        console.log("    ");
        heartCheck.start();
    }
    websocket.onclose = function (ev) {
        console.log("    ");
        if (ev.code != 4500) {
            reconnect();
        }
    }
    websocket.onmessage = function (ev) {
        console.log("    :" + ev.data);
        heartCheck.reset();
        if(ev.data=='new-order'){
            //     
            myAuto.play();
	}
    }
    websocket.onerror = function (ev) {
        console.log("      ");
    }
    window.onbeforeunload = function (ev) {
        websocket.close();
    }

}

ここではhttpsを使っているのでwebsocketはwssです.