zookeeper递归删除znode节点java Demo

因为zookeeper只允许删除叶子节点，如果要删除非叶子节点，只能使用递归，zookeeper的文件结构是树型结构，和linux的目录结构相似，所有程序和我之前写的递归删除本地文件和递归删除hdfs上的文件是差不多的，这里也分享下吧。

下面是zookeeper的存储结构示意图：

如果要删除上面方块节点，必须递归删除，圆形的叶子节点可以直接删除。

• 1.MyWatch类

/** * 自定义watch类，不做任何事 * @author LiJie *  */class MyWatch implements Watcher {    @Override    public void process(WatchedEvent event) {        // DO Nothing    }}

• 2.主程序

package com.lijie.zk1;import java.io.IOException;import java.util.List;import org.apache.zookeeper.WatchedEvent;import org.apache.zookeeper.Watcher;import org.apache.zookeeper.ZooKeeper;/** * zookeeper znode递归删除 * @author LiJie * */public class RmrDemo {    private static final String connectString = "hadoop01:2181,hadoop02:2181,hadoop03:2181";    private static final int sessionTimeout = 2000;    private static ZooKeeper zookeeper = null;    /**     * main函数     * @param args     * @throws Exception     */    public static void main(String[] args) throws Exception {        //调用rmr,删除所有目录        rmr("/");    }    /**     * 递归删除 因为zookeeper只允许删除叶子节点，如果要删除非叶子节点，只能使用递归     * @param path     * @throws IOException     */    public static void rmr(String path) throws Exception {        ZooKeeper zk = getZookeeper();        //获取路径下的节点        List<String> children = zk.getChildren(path, false);        for (String pathCd : children) {            //获取父节点下面的子节点路径            String newPath = "";            //递归调用,判断是否是根节点            if (path.equals("/")) {                newPath = "/" + pathCd;            } else {                newPath = path + "/" + pathCd;            }            rmr(newPath);        }        //删除节点,并过滤zookeeper节点和 /节点        if (path != null && !path.trim().startsWith("/zookeeper") && !path.trim().equals("/")) {            zk.delete(path, -1);            //打印删除的节点路径            System.out.println("被删除的节点为：" + path);        }    }    /**     * 获取Zookeeper实例     * @return     * @throws IOException     */    public static ZooKeeper getZookeeper() throws IOException {        zookeeper = new ZooKeeper(connectString, sessionTimeout, new MyWatch());        return zookeeper;    }}

• 3.创建几个测试目录

[zk: localhost:2181(CONNECTED) 0] ls /[zookeeper][zk: localhost:2181(CONNECTED) 1] create /lijie 1   Created /lijie[zk: localhost:2181(CONNECTED) 2] create /lijie/test1 2Created /lijie/test1[zk: localhost:2181(CONNECTED) 3] create /lijie/test1/test2 3Created /lijie/test1/test2[zk: localhost:2181(CONNECTED) 4] create /lijie/test1/test3 4Created /lijie/test1/test3

• 4.运行程序，查看结果