【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!