聊聊、Zookeeper 客户端 Curator

【Curator】 

 和 ZkClient 一样，Curator 也是开源客户端，Curator 是 Netflix 公司开源的一套框架。

<dependency>
	<groupId>org.apache.curator</groupId>
	<artifactId>curator-framework</artifactId>
	<version>2.8.0</version>
</dependency>

 创建连接

•  static CuratorFramework newClient(String connectString,RetryPolicy retryPolicy)
• static CuratorFramework newClient(String connectString,int sessionTimeOutMs,int connectionTimeOutMs,RetryPolicy retryPolicy)

和原生 API，ZkClient 客户端都不一样，Curator 通过 CuratorFrameworkFactory 来创建客户端，然后调用 start 方法来启动。

package zookeeper.curator;

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

public class OpenCuratorClient {

	public static void main(String[] args) {
		RetryPolicy policy = new ExponentialBackoffRetry(1000, 3);
		CuratorFramework client = CuratorFrameworkFactory.newClient("127.0.0.1:2181",5000,3000,policy);
		client.start();

	}

}

ExponentialBackoffRetry 是 SleepingRetry 实现类，而 SleepingRetry 又是 RetryPolicy 接口实现类。ExponentialBackoffRetry(1000, 3) 表示初始 sleep 时间 1 秒，重试次数为 3。

创建节点

• public CreateBuilder create()
• public ProtectACLCreateModePathAndBytesable<String> creatingParentsIfNeeded()
• public T withMode(CreateMode mode)
• public T forPath(String path,byte[] data) throws Exception
• public T forPath(String path) throws Exception

package zookeeper.curator;

import org.apache.curator.RetryPolicy;
import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.CuratorFrameworkFactory;
import org.apache.curator.retry.ExponentialBackoffRetry;
import org.apache.zookeeper.CreateMode;

public class OpenCuratorClient {

	public static void main(String[] args) {

		RetryPolicy policy = new ExponentialBackoffRetry(1000, 3);
		CuratorFramework client = CuratorFrameworkFactory.newClient("127.0.0.1:2181",5000,3000,policy);
		client.start();

		try {

			client.create().creatingParentsIfNeeded().withMode(CreateMode.EPHEMERAL).forPath("/app2","app2".getBytes());

		} catch (Exception e1) {
			e1.printStackTrace();
		}

		try {
			Thread.sleep(Integer.MAX_VALUE);
		} catch (InterruptedException e) {
			e.printStackTrace();
		}

	}

}

　　

谢谢大家观看！