java WebSocket, 如何只发一个信息，就停止。

Question

用JAVA websocket 发信息，用的是tyrus 工具包。 client 端代码如下：

package websockets;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.concurrent.CountDownLatch;
import javax.websocket.ClientEndpoint;
import javax.websocket.CloseReason;
import javax.websocket.DeploymentException;
import javax.websocket.OnClose;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import org.glassfish.tyrus.client.ClientManager;

@ClientEndpoint
public class ChatClientEndpoint {

    private static CountDownLatch latch;

    @OnOpen
    public void onOpen(Session session) {
        System.out.println("--- Connected " + session.getId());
        try {
            session.getBasicRemote().sendText("Sk_execute");
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    @OnMessage
    public String onMessage(String message, Session session) {
        BufferedReader bufferRead = new BufferedReader(new InputStreamReader(System.in));
        try {
            System.out.println("--- Received: " + message);
            String userInput = bufferRead.readLine();
               CloseReason closeReason = null;
                this.onClose(session, closeReason);
                session.close();

            }
            return userInput;
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    @OnClose
    public void onClose(Session session, CloseReason closeReason) {
        System.out.println("Session " + session.getId()
                + " closed because " + closeReason);
        //latch.countDown();
    }

    public static void main(String[] args) {
        latch = new CountDownLatch(1);
        ClientManager client = ClientManager.createClient();
        try {
            URI uri = new URI("ws://192.168.1.10:3000/");
            client.connectToServer(ChatClientEndpoint.class, uri);

            latch.await();

        } catch (DeploymentException | URISyntaxException | InterruptedException e) {
            e.printStackTrace();
        }
    }
}

我现在想实现，我client 发一个信号后，关闭线程。如何操作？现阶段的代码是 信息一直在发送。除此之外， @OnMessage 这个方法中的下面两行用不了。
this.onClose(session, closeReason);
session.close();

我想实现的是，client 收到一个信息后，关闭线程。

Answer 1

@OnMessage
    public String onMessage(String message, Session session) {
        BufferedReader bufferRead = new BufferedReader(new InputStreamReader(System.in));
        try {
            System.out.println("--- Received: " + message);
            String userInput = bufferRead.readLine();
               CloseReason closeReason = null;
                this.onClose(session, closeReason);
                session.close();
 
            }
            return userInput;
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

问题在这里，你把
CloseReason closeReason = null;
this.onClose(session, closeReason);
这两句去掉，这是close事件，只要调用close方法就行，而且你把 CloseReason closeReason = null;可能会引起onClose中执行代码异常，导致真正的连接关闭代码close不被执行，所以结果就是没关闭。