Java使用Curator进行ZooKeeper操作的详细教程

<!-- zookeeper支持 -->
<dependency>
   <groupId>org.apache.zookeeper</groupId>
   <artifactId>zookeeper</artifactId>
   <version>3.6.4</version>
</dependency>
<!-- curator-recipes -->
<dependency>
   <groupId>org.apache.curator</groupId>
   <artifactId>curator-recipes</artifactId>
   <version>5.5.0</version>
</dependency>
<!-- curator-framework -->
<dependency>
   <groupId>org.apache.curator</groupId>
   <artifactId>curator-framework</artifactId>
   <version>5.5.0</version>
</dependency>

import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.CuratorFrameworkFactory;
import org.apache.curator.retry.ExponentialBackoffRetry;

public class CuratorExample {
    public static void main(String[] args) {
        // 创建 CuratorFramework 实例
        CuratorFramework client = CuratorFrameworkFactory.builder()
                .connectString("127.0.0.1:2181") // ZooKeeper 地址
                .sessionTimeoutMs(5000)
                .connectionTimeoutMs(3000)
                .retryPolicy(new ExponentialBackoffRetry(1000, 3))
                .build();

        // 启动客户端
        client.start();

        System.out.println("CuratorFramework 已启动");

        // 关闭客户端
        client.close();
    }
}

import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.CuratorFrameworkFactory;
import org.apache.curator.retry.ExponentialBackoffRetry;
import org.apache.curator.framework.recipes.locks.InterProcessMutex;

import java.util.concurrent.TimeUnit;

public class DistributedLockExample {
    public static void main(String[] args) throws Exception {
        // 初始化 CuratorFramework
        CuratorFramework client = CuratorFrameworkFactory.builder()
                .connectString("127.0.0.1:2181")
                .retryPolicy(new ExponentialBackoffRetry(1000, 3))
                .build();
        client.start();

        // 创建分布式锁
        InterProcessMutex lock = new InterProcessMutex(client, "/distributed-lock");

        // 尝试获取锁
        if (lock.acquire(10, TimeUnit.SECONDS)) {
            try {
                System.out.println("成功获取锁，执行任务...");
                Thread.sleep(5000); // 模拟任务
            } finally {
                lock.release();
                System.out.println("锁已释放");
            }
        } else {
            System.out.println("未能获取锁");
        }

        client.close();
    }
}

import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.CuratorFrameworkFactory;
import org.apache.curator.retry.ExponentialBackoffRetry;
import org.apache.curator.framework.recipes.leader.LeaderSelector;
import org.apache.curator.framework.recipes.leader.LeaderSelectorListenerAdapter;

public class LeaderElectionExample {
    public static void main(String[] args) throws InterruptedException {
        CuratorFramework client = CuratorFrameworkFactory.builder()
                .connectString("127.0.0.1:2181")
                .retryPolicy(new ExponentialBackoffRetry(1000, 3))
                .build();
        client.start();

        // 创建 LeaderSelector
        LeaderSelector leaderSelector = new LeaderSelector(client, "/leader-election", new LeaderSelectorListenerAdapter() {
            @Override
            public void takeLeadership(CuratorFramework client) throws Exception {
                System.out.println("成为 Leader，执行任务...");
                Thread.sleep(3000); // 模拟任务
                System.out.println("任务完成，释放 Leader 权限");
            }
        });

        leaderSelector.autoRequeue(); // 自动重新排队参与选举
        leaderSelector.start();

        Thread.sleep(Integer.MAX_VALUE); // 保持主线程运行
        client.close();
    }
}

import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.CuratorFrameworkFactory;
import org.apache.curator.framework.recipes.cache.NodeCache;
import org.apache.curator.retry.ExponentialBackoffRetry;

public class NodeCacheExample {
    public static void main(String[] args) throws Exception {
        CuratorFramework client = CuratorFrameworkFactory.builder()
                .connectString("127.0.0.1:2181")
                .retryPolicy(new ExponentialBackoffRetry(1000, 3))
                .build();
        client.start();

        // 创建 NodeCache
        NodeCache nodeCache = new NodeCache(client, "/test-node");
        nodeCache.getListenable().addListener(() -> {
            System.out.println("节点数据变更，新的数据为：" + new String(nodeCache.getCurrentData().getData()));
        });

        nodeCache.start();

        // 创建节点并修改数据
        client.create().orSetData().forPath("/test-node", "initial-data".getBytes());
        Thread.sleep(1000);
        client.setData().forPath("/test-node", "updated-data".getBytes());

        Thread.sleep(5000); // 保持运行观察结果
        client.close();
    }
}