java websocket心跳检测重连代码

以下是一个简单的Java WebSocket心跳检测和重连的代码示例：

import java.net.URI;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
import javax.websocket.ClientEndpoint;
import javax.websocket.CloseReason;
import javax.websocket.ContainerProvider;
import javax.websocket.OnClose;
import javax.websocket.OnError;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.WebSocketContainer;

@ClientEndpoint
public class WebSocketClient {

    private Session session;
    private ScheduledExecutorService executor = Executors.newSingleThreadScheduledExecutor();

    @OnOpen
    public void onOpen(Session session) {
        System.out.println("Connected to server");
        this.session = session;
        startHeartbeat();
    }

    @OnMessage
    public void onMessage(String message) {
        System.out.println("Received message: " + message);
    }

    @OnClose
    public void onClose(CloseReason reason) {
        System.out.println("Connection closed: " + reason.getReasonPhrase());
        stopHeartbeat();
        reconnect();
    }

    @OnError
    public void onError(Throwable throwable) {
        System.out.println("Error: " + throwable.getMessage());
        stopHeartbeat();
        reconnect();
    }

    private void startHeartbeat() {
        executor.scheduleAtFixedRate(() -> {
            try {
                session.getBasicRemote().sendText("ping");
            } catch (Exception e) {
                System.out.println("Error sending heartbeat: " + e.getMessage());
            }
        }, 0, 30, TimeUnit.SECONDS);
    }

    private void stopHeartbeat() {
        executor.shutdown();
    }

    private void reconnect() {
        WebSocketContainer container = ContainerProvider.getWebSocketContainer();
        try {
            container.connectToServer(this, new URI("wss://example.com"));
        } catch (Exception e) {
            System.out.println("Error reconnecting: " + e.getMessage());
        }
    }
}

在上面的示例中，`startHeartbeat()` 方法使用定时器每30秒向服务器发送一个心跳消息。如果发送心跳消息失败，则会在控制台记录错误消息并停止心跳定时器。

如果WebSocket连接关闭或发生错误，`onClose()` 或 `onError()` 方法将会被调用，这时代码将会停止心跳定时器并尝试重新连接。重新连接使用的是Java WebSocket API的内置功能。

你可以根据自己的需求调整心跳间隔时间和重连策略。