package cn.itcast.bigdata.zk;import java.io.IOException;import java.util.List;import org.apache.zookeeper.CreateMode;import org.apache.zookeeper.KeeperException;import org.apache.zookeeper.WatchedEvent;import org.apache.zookeeper.Watcher;import org.apache.zookeeper.ZooDefs.Ids;import org.apache.zookeeper.ZooKeeper;import org.apache.zookeeper.data.Stat;import org.junit.Before;import org.junit.Test;public class SimpleZkClient {	private static final String connectString = "mini1:2181,mini2:2181,mini3:2181";	private static final int sessionTimeout = 2000;	ZooKeeper zkClient = null;	@Before	public void init() throws Exception {		zkClient = new ZooKeeper(connectString, sessionTimeout, new Watcher() {			@Override			public void process(WatchedEvent event) {				// 收到事件通知后的回调函数（应该是我们自己的事件处理逻辑）				System.out.println(event.getType() + "---" + event.getPath());				try {					zkClient.getChildren("/", true);				} catch (Exception e) {				}			}		});	}	/**	 * 数据的增删改查	 * 	 * @throws InterruptedException	 * @throws KeeperException	 */	// 创建数据节点到zk中	public void testCreate() throws KeeperException, InterruptedException {		// 参数1：要创建的节点的路径 参数2：节点大数据 参数3：节点的权限 参数4：节点的类型		String nodeCreated = zkClient.create("/eclipse", "hellozk".getBytes(), Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);		//上传的数据可以是任何类型，但都要转成byte[]	}	//判断znode是否存在	@Test		public void testExist() throws Exception{		Stat stat = zkClient.exists("/eclipse", false);		System.out.println(stat==null?"not exist":"exist");					}		// 获取子节点	@Test	public void getChildren() throws Exception {		List
    
      children = zkClient.getChildren("/", true);		for (String child : children) {			System.out.println(child);		}		Thread.sleep(Long.MAX_VALUE);	}	//获取znode的数据	@Test	public void getData() throws Exception {				byte[] data = zkClient.getData("/eclipse", false, null);		System.out.println(new String(data));			}		//删除znode	@Test	public void deleteZnode() throws Exception {				//参数2：指定要删除的版本，-1表示删除所有版本		zkClient.delete("/eclipse", -1);					}	//删除znode	@Test	public void setData() throws Exception {				zkClient.setData("/app1", "imissyou angelababy".getBytes(), -1);				byte[] data = zkClient.getData("/app1", false, null);		System.out.println(new String(data));			}		}