zookeeper使用实例

以下是一个使用ZooKeeper的Java示例：

import org.apache.zookeeper.*;

public class ZooKeeperExample implements Watcher {

    private static final String ZOOKEEPER_ADDRESS = "localhost:2181";
    private static final int SESSION_TIMEOUT = 3000;

    private ZooKeeper zooKeeper;

    public static void main(String[] args) {
        try {
            ZooKeeperExample example = new ZooKeeperExample();
            example.connect();
            example.createNode("/myNode", "myNodeData");
            String data = example.getData("/myNode");
            System.out.println("Data: " + data);
            example.deleteNode("/myNode");
            example.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void connect() throws Exception {
        zooKeeper = new ZooKeeper(ZOOKEEPER_ADDRESS, SESSION_TIMEOUT, this);
    }

    public void createNode(String path, String data) throws Exception {
        zooKeeper.create(path, data.getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
    }

    public String getData(String path) throws Exception {
        byte[] data = zooKeeper.getData(path, false, null);
        return new String(data);
    }

    public void deleteNode(String path) throws Exception {
        zooKeeper.delete(path, -1);
    }

    public void close() throws Exception {
        zooKeeper.close();
    }

    @Override
    public void process(WatchedEvent event) {
        // Do nothing
    }
}

这个实例创建了一个ZooKeeper连接，然后它创建了一个节点，获取节点的数据，删除节点，最后关闭连接。关键点在于使用ZooKeeper类来连接到ZooKeeper服务并执行操作。此外，还需要实现Watcher接口，以便处理ZooKeeper事件。