zookeeper分布式配置管理

配置中心代码：

package test2;

import java.io.IOException;
import java.io.PrintStream;
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;
import org.apache.zookeeper.ZooDefs.Ids;
import org.apache.zookeeper.ZooKeeper;
import org.apache.zookeeper.data.Stat;

public class ConfigCenter implements Watcher {
	ZooKeeper zk = null;
	String znode;

	ConfigCenter(String address, String znode) {
		this.znode = znode;
		try {
			this.zk = new ZooKeeper(address, 3000, this);
			Stat st = this.zk.exists("/root1", true);
			if (st == null) {
			      this.zk.create(znode, new byte[0], ZooDefs.Ids.OPEN_ACL_UNSAFE, 
			    	        CreateMode.PERSISTENT);
			}
		} catch (IOException e) {
			e.printStackTrace();
			this.zk = null;
		} catch (KeeperException e) {
			e.printStackTrace();
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
	}
	
	public void process(WatchedEvent event) {
		System.out.println(event.toString());
		try {
			this.zk.exists("/root1", true);
		} catch (KeeperException e) {
			e.printStackTrace();
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
	}

	void updateConfig(String str) {
		try {
			Stat s = this.zk.exists(this.znode, true);
			this.zk.setData(this.znode, str.getBytes(), s.getVersion());
		} catch (Exception e) {
			e.printStackTrace();
		}
	}	
}

package test2;

import java.io.IOException;
import java.io.PrintStream;
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;
import org.apache.zookeeper.ZooDefs.Ids;
import org.apache.zookeeper.data.Stat;
import org.apache.zookeeper.ZooKeeper;

public class ZooKeeperWatcher implements Watcher ,Runnable {
	
	private ZooKeeper zooKeeper = null;
	private String znode;

	public ZooKeeper getZooKeeper() {
		return this.zooKeeper;
	}

	public void connect(String hosts, String znode) throws IOException,
			InterruptedException, KeeperException {
		this.zooKeeper = new ZooKeeper(hosts, 2000, this);
		this.znode = znode;
		this.zooKeeper.exists(znode, true);
	}

	public void setData(byte[] data) {
		try {
			Stat s = this.zooKeeper.exists(znode, false);
			this.zooKeeper.setData(znode, data, s.getVersion());
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	public void process(WatchedEvent event) {
		System.out.println(event.toString());
		try {
			this.zooKeeper.exists(znode, true);//不知道为什么一定要加上这句话，下次事件到来时，才会触发process事件
		} catch (KeeperException e) {
			e.printStackTrace();
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
	}
	
	public void run() {
		try {
			synchronized (this) {
                           while (true) {
                              wait();
                            }
                        }
		} catch (InterruptedException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}

}

package test2;

import java.io.IOException;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.ZooKeeper;

public class test {
	public static void main(String[] args) throws IOException, InterruptedException, KeeperException {
		ZooKeeperWatcher zw1 = new ZooKeeperWatcher();
		zw1.connect("127.0.0.1", "/root1");
		ZooKeeperWatcher zw2 = new ZooKeeperWatcher();
		zw2.connect("127.0.0.1", "/root1");
		new Thread(zw1).start();
		new Thread(zw2).start();
		ConfigCenter cc = new ConfigCenter("127.0.0.1","/root1");
		cc.updateConfig("a");
		cc.updateConfig("b");
		cc.updateConfig("c");
		cc.updateConfig("d");
	}
}