Curator教程（一）快速入门

Curator是Netflix公司开源的一个Zookeeper客户端，与Zookeeper提供的原生客户端相比，Curator的抽象层次更高，简化了Zookeeper客户端编程。

它包含以下几个组件：

环境配置

• JDK 1.7
• Zookeeper 3.4.8
• Curator 2.11.1
• Maven 3.3

快速入门

Maven依赖

<properties>
    <java.version>1.7</java.version>
    <curator.version>2.11.1</curator.version>
</properties>

<dependencies>
    <dependency>
        <groupId>org.apache.zookeeper</groupId>
        <artifactId>zookeeper</artifactId>
        <version>3.4.8</version>
        <exclusions>
            <exclusion>
                <artifactId>slf4j-log4j12</artifactId>
                <groupId>org.slf4j</groupId>
            </exclusion>
            <exclusion>
                <artifactId>log4j</artifactId>
                <groupId>log4j</groupId>
            </exclusion>
        </exclusions>
    </dependency>

    <dependency>
        <groupId>org.apache.curator</groupId>
        <artifactId>curator-framework</artifactId>
        <version>${curator.version}</version>
    </dependency>
    <dependency>
        <groupId>org.apache.curator</groupId>
        <artifactId>curator-client</artifactId>
        <version>${curator.version}</version>
        <exclusions>
            <exclusion>
                <groupId>com.google.guava</groupId>
                <artifactId>guava</artifactId>
            </exclusion>
        </exclusions>
    </dependency>

    <dependency>
        <groupId>com.google.guava</groupId>
        <artifactId>guava</artifactId>
        <version>18.0</version>
    </dependency>
</dependencies>

1.创建Curator 连接实例

String address = "localhost:2181";
CuratorFramework client = CuratorFrameworkFactory.newClient(address, new ExponentialBackoffRetry(1000, 3));

注意：一个Zookeeper集群只需要构造一个CuratorFramework 实例对象即可。

CuratorFramework 使用之前必须先调用

client.start();

完成一系列操作后，调用client.close();方法，可以使用try-finally语句：

CuratorFramework client = CuratorFrameworkFactory.newClient(address, new ExponentialBackoffRetry(1000, 3));
try{
    client.start();
    ...
}finally {
    if(client!=null)
        client.close();
}

2.创建节点

a. 创建永久性节点

client.create()
      .creatingParentContainersIfNeeded()
      .withMode(CreateMode.PERSISTENT)
      .withACL(ZooDefs.Ids.OPEN_ACL_UNSAFE)
      .forPath(path, "hello, zk".getBytes());

b. 创建临时节点

client.create().withMode(CreateMode.EPHEMERAL).forPath(path, "hello".getBytes());  

3.获取节点值

byte[] buf = client.getData().forPath(path);
System.out.println("get data path:"+path+", data:"+new String(buf));

4.设置节点值

client.setData().inBackground().forPath(path, "ricky".getBytes());

5.checkExists

Stat stat = client.checkExists().forPath(path);
if(stat==null){
    System.out.println("exec create path:"+path);
}else {
    System.out.println("exec getData");
}

6.删除节点

client.delete().deletingChildrenIfNeeded().forPath("/pandora");

点此下载完整代码：https://github.com/TiFG/zookeeper-samples

参考

Getting Started：http://curator.apache.org/getting-started.html