WebSocketServer

@Component
@ServerEndpoint(value = "/endpoint/ws")
public class WebSocketServer {
    private final Logger logger = LoggerFactory.getLogger(getClass());
    private static final AtomicInteger onlineCount = new AtomicInteger();
    @OnOpen
    public void onOpen(Session session, @PathParam("sid") String sid) {
        //在線數加1
        onlineCount.incrementAndGet();
        logger.info("新窗口監聽 {}, 當前在線人數 {}",sid,onlineCount.get());
    }

    @OnClose
    public void onClose() {
        //在線數減1
        onlineCount.decrementAndGet();
        logger.info("連接關閉, 當前在線人數為 {}",onlineCount.get());
    }

    @OnError
    public void onError(Session session, Throwable error) {
        logger.warn("發生錯誤, 非正常關閉 {}, 當前在線人數為 {}", onlineCount.get());
    }
}