zookeeper之客户端Curator的使用

Curator是一个开源的zookeeper客户端，解决了很多zookeeper原生客户端非常底层的细节开发工作，如连接重试、反复注册watcher等。

public class CuratorOperator {

    // zookeeper地址
    private static final String zkServers = "127.0.0.1:2181";
    private static final String path = "/mynode";

    public static void main(String[] args) throws Exception {
        //重试策略
        RetryPolicy retryPolicy = new ExponentialBackoffRetry(1000, 3);
        //RetryPolicy retryPolicy = new RetryNTimes(5, 500);

        //1.创建zk客户端
        //第一种方式
        //CuratorFramework client = CuratorFrameworkFactory.newClient(zkServerPath, retryPolicy);

        //第二种方式
        CuratorFramework client = CuratorFrameworkFactory.builder().connectString(zkServers)
                .sessionTimeoutMs(5000)//会话超时
                .connectionTimeoutMs(5000)//连接超时
                .retryPolicy(retryPolicy)//重试策略
                .build();

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

        //2.创建节点
        String data = "hello";
        client.create()
                .creatingParentsIfNeeded()//若创建节点的父节点不存在则会先创建父节点再创建子节点
                .withMode(CreateMode.EPHEMERAL)//节点类型
                .forPath(path, data.getBytes());

        //3.获取节点的所有子节点
        System.out.println(client.getChildren().forPath("/"));

        //4.获取节点的数据
        byte[] buf = client.getData().forPath(path);
        System.out.println(new String(buf));

        //5.修改节点数据
        String newData = "world";
        client.setData().forPath(path, newData.getBytes());
        buf = client.getData().forPath(path);
        System.out.println(new String(buf));

        //6.删除节点
        client.delete().forPath(path);
        System.out.println(client.getChildren().forPath("/"));

        //7.关闭zk客户端连接
        if (client != null) {
            client.close();
        }
    }

}