帮我写一个zookeeper心跳代码java

好的，下面是一个简单的 ZooKeeper 心跳代码示例，使用 Java 实现：

import org.apache.zookeeper.*;
import org.apache.zookeeper.data.Stat;

import java.io.IOException;
import java.util.concurrent.CountDownLatch;

public class Heartbeat {

    private static final int SESSION_TIMEOUT = 5000;
    private static final String ZOOKEEPER_ADDRESS = "localhost:2181";
    private static final String Z_NODE = "/heartbeats";

    private ZooKeeper zooKeeper;
    private CountDownLatch latch;

    public Heartbeat() throws IOException, InterruptedException, KeeperException {
        latch = new CountDownLatch(1);
        zooKeeper = new ZooKeeper(ZOOKEEPER_ADDRESS, SESSION_TIMEOUT, new Watcher() {
            @Override
            public void process(WatchedEvent event) {
                if (event.getState() == Event.KeeperState.SyncConnected) {
                    System.out.println("Connected to ZooKeeper");
                    latch.countDown();
                }
            }
        });
        latch.await();
        createHeartbeatNode();
    }

    private void createHeartbeatNode() throws KeeperException, InterruptedException {
        Stat stat = zooKeeper.exists(Z_NODE, false);
        if (stat == null) {
            zooKeeper.create(Z_NODE, new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
        }
        sendHeartbeat();
    }

    private void sendHeartbeat() throws KeeperException, InterruptedException {
        String zNode = zooKeeper.create(Z_NODE + "/heartbeat", new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL_SEQUENTIAL);
        System.out.println("Sent heartbeat to " + zNode);
    }

    public static void main(String[] args) throws IOException, InterruptedException, KeeperException {
        Heartbeat heartbeat = new Heartbeat();
        while (true) {
            Thread.sleep(5000);
            heartbeat.sendHeartbeat();
        }
    }
}

在上面的代码中，我们使用 ZooKeeper 的 Java API 进行心跳检测。我们首先连接到 ZooKeeper，然后创建一个 `/heartbeats` 节点，然后每隔 5 秒钟发送一个心跳到 `/heartbeats/heartbeat` 路径下。

在 `createHeartbeatNode()` 方法中，我们首先检查 `/heartbeats` 节点是否存在，如果不存在，则创建它。在 `sendHeartbeat()` 方法中，我们创建一个带有自增序列的临时节点 `/heartbeats/heartbeat`，每次发送心跳时都会创建一个新的节点。

请注意，这只是一个简单的示例代码，实际上，您可能需要更复杂的逻辑来处理心跳和节点失效等情况。