ZooKeeper——入门

ZooKeeper——入门

博客分类：

• ZooKeeper

ZooKeeper 

1.从http://zookeeper.apache.org下载最新版本的ZooKeeper(当前最新版为zookeeper-3.4.5)

 

2.$ tar zxf zookeeper-3.4.5.tar.gz解压

 

3.在conf目录下创建配置文件zoo.cfg

tickTime=2000
dataDir=/home/lan/zookeeper
clientPort=2181

tickTime=2000
dataDir=/home/lan/zookeeper
clientPort=2181

 tickTime是发送心跳包的时间间隔

 dataDir用于存储Zookeeper的内存数据库快照和更新事务日志（日志目录可另外配置）

 clientPort端口用于监听客户端连接

 

4.启动ZooKeeper

 

5.连接ZooKeeper

 

5.在shell中通过help命令查看客户端可以执行哪些命令

 

6.通过ls命令查看根目录

  

7.创建一个znode

 
 8.读取znode

 

9.修改znode

 

10.删除znode

 

package zookeeper.demo;

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

import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.Watcher.Event.KeeperState;
import org.apache.zookeeper.ZooDefs.Ids;
import org.apache.zookeeper.ZooKeeper;
import org.apache.zookeeper.data.Stat;

public class ZooKeeperTestCase implements Watcher {

    private static ZooKeeper zk;
    private String path;
    private Stat stat;
    private static CountDownLatch countDown = new CountDownLatch(1);

    public ZooKeeperTestCase(){
        if(zk == null){
            try {
                System.out.println("Starting ZK:");
                zk = new ZooKeeper("192.168.202.129", 3000, this);
                countDown.await();
                System.out.println("Finished starting ZK: " + zk);
            } catch (IOException e) {
                zk = null;
                e.printStackTrace();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }

    @Override
    public void process(WatchedEvent event) {
        if(event.getState() == KeeperState.SyncConnected){
            countDown.countDown();
        }
        System.out.println("-----"+event.getState());
    }

    public void create() throws KeeperException, InterruptedException{
        path = zk.create("/zk_java", "java_binding".getBytes(), Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT_SEQUENTIAL);
        System.out.println("created znode:" + path);
    }

    public void list() throws KeeperException, InterruptedException{
        List<String> strings = zk.getChildren("/", true);
        System.out.println("list:"+strings);
    }

    public void exist() throws KeeperException, InterruptedException{
        stat = zk.exists(path, true);
        System.out.println("exits:"+stat.getDataLength());
    }

    public void get() throws KeeperException, InterruptedException{
        Stat stat = new Stat();
        byte[] data = zk.getData(path, true, stat);
        System.out.print(new String(data));
        System.out.println(stat);
    }

    public void set() throws KeeperException, InterruptedException{
        stat = zk.setData(path, "zk_ooxx".getBytes(), stat.getVersion());
    }

    public void delete() throws InterruptedException, KeeperException{
        zk.delete(path, stat.getVersion());
    }

    public void close() throws InterruptedException{
        zk.close();
    }

    public static void main(String[] args) throws Exception {
        ZooKeeperTestCase zkTest = new ZooKeeperTestCase();

        zkTest.list();

        zkTest.create();
        zkTest.list();

        zkTest.exist();
        zkTest.get();

        zkTest.set();
        zkTest.get();

        zkTest.delete();
        zkTest.list();

        zkTest.close();
    }
}