zookeeper

package com.cdn.zookeeper.zookeeper;

import org.apache.zookeeper.*;
import org.apache.zookeeper.data.Stat;

import java.util.List;
import java.util.concurrent.CountDownLatch;

/**
 * 功能简述：
 * author CDN
 * create 2019-06-02 00:59
 * VERSION 1.0.0
 */
public class BaseZookeeper implements Watcher {

    private ZooKeeper zookeeper;
    /** zookeeper地址 */
    private static final String CONNECT_ADDR = "127.0.0.1:2181,192.168.80.87:2181,192.168.80.86:2181";
    /** session超时时间 */
    private static final int SESSION_TIME_OUT = 2000;//ms
    /** 信号量，阻塞程序执行，用于等待zookeeper连接成功，发送成功信号 */
    private CountDownLatch countDownLatch = new CountDownLatch(1);


    @Override
    public void process(WatchedEvent event) {
        if (event.getState() == Event.KeeperState.SyncConnected) {
            System.out.println("Watch received event");
            countDownLatch.countDown();
        }
    }


    /**
     * 连接zookeeper
     *     * @param host
     *     * @throws Exception
     *    
     */
    void connectZookeeper() throws Exception {
        zookeeper = new ZooKeeper(CONNECT_ADDR, SESSION_TIME_OUT, this);
        //进行阻塞
        countDownLatch.await();
        System.out.println("zookeeper 连接成功");
    }

    /**
     *     * 创建节点
     *     * @param path
     *     * @param data
     *     * @throws Exception
     *    
     */
    public String createNode(String path, String data) throws Exception {
        return this.zookeeper.create(path, data.getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
    }

    /**
     *     * 获取路径下所有子节点
     *     * @param path
     *     * @return
     *     * @throws KeeperException
     *     * @throws InterruptedException
     *    
     */

    public List<String> getChildren(String path) throws KeeperException, InterruptedException {
        List<String> children = zookeeper.getChildren(path, false);
        return children;
    }

    /**
     *     * 获取节点上面的数据
     *     * @param path  路径
     *     * @return
     *     * @throws KeeperException
     *     * @throws InterruptedException
     *    
     */
    public String getData(String path) throws KeeperException, InterruptedException {
        byte[] data = zookeeper.getData(path, false, null);
        if (data == null) {
            return "";
        }
        return new String(data);
    }

    /**
     *     * 设置节点信息
     *     * @param path  路径
     *     * @param data  数据
     *     * @return
     *     * @throws KeeperException
     *     * @throws InterruptedException
     *    
     */
    public Stat setData(String path, String data) throws KeeperException, InterruptedException {
        Stat stat = zookeeper.setData(path, data.getBytes(), -1);
        return stat;
    }

    /**
     *     * 删除节点
     *     * @param path
     *     * @throws InterruptedException
     *     * @throws KeeperException
     *    
     */
    public void deleteNode(String path) throws InterruptedException, KeeperException {
        zookeeper.delete(path, -1);
    }

    /**
     *     * 获取创建时间
     *     * @param path
     *     * @return
     *     * @throws KeeperException
     *     * @throws InterruptedException
     *    
     */
    public String getCTime(String path) throws KeeperException, InterruptedException {
        Stat stat = zookeeper.exists(path, false);
        return String.valueOf(stat.getCtime());
    }

    /**
     *     * 获取某个路径下孩子的数量
     *     * @param path
     *     * @return
     *     * @throws KeeperException
     *     * @throws InterruptedException
     *    
     */
    public Integer getChildrenNum(String path) throws KeeperException, InterruptedException {
        int childenNum = zookeeper.getChildren(path, false).size();
        return childenNum;
    }

    /**
     *     * 关闭连接
     *     * @throws InterruptedException
     *    
     */
    public void closeConnection() throws InterruptedException {
        if (zookeeper != null) {
            zookeeper.close();
        }
    }
}