Zookeeper API JAVA 解析

常用方法：

• new ZooKeeper()構造方法
• create
• exists
• getChildren
• getData

注意點：

watcher 的觸發，為一次性。

測試程序

package zookeeper;

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;

public class ZookeeperTest {

public static final int Zookeeper_SESSION_TIMEOUT = 20000;

static ZooKeeper zk;

static class TestWatcher implements Watcher {

@Override
public void process(WatchedEvent event) {
// TODO Auto-generated method stub
System.out.println("come from TestWatcher-> process");
}

}

static TestWatcher watcher = new TestWatcher();

/**
* new ZooKeeper
* 初始化 ZooKeeper 實例
*/
public static void createZKInstance() throws IOException, KeeperException,
InterruptedException {
zk = new ZooKeeper("ip:port,ip:port", Zookeeper_SESSION_TIMEOUT,watcher);
}

/**
* create
* 創建節點
*/
public static void createNode(String node) throws IOException, InterruptedException,KeeperException
{
if (zk.exists(node, null) == null) {
zk.create(node,node.getBytes(), Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL);
}
}

/**
* exists
* 判斷節點是否存在
*/
public static boolean isExists(String node) throws InterruptedException,
KeeperException {
if (zk.exists(node, null) == null) {
return false;
}
return true;
}

/**
* getChildren
* 獲取一個節點的子節點列表
*/
public static List<String> getChildren(String node) throws KeeperException, InterruptedException{
return zk.getChildren(node, null);
}

/**
* 返回節點的數據
*/
public static byte[] getDate(String path ) throws KeeperException, InterruptedException{
return zk.getData(path, null, null);
}

public static void main(String[] args) {
try {
createZKInstance();

createNode("/testnodes");

} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (KeeperException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}

}

ZooKeeper 的詳細介紹：請點這裡
ZooKeeper 的下載地址：請點這裡