zclient1.java

package com.myfirstjava.program;
import org.apache.zookeeper.*;
import org.apache.zookeeper.Watcher.Event.KeeperState;
import org.apache.zookeeper.AsyncCallback.StatCallback;
import org.apache.zookeeper.data.*;
import java.io.*;
import java.util.Scanner;
import java.util.concurrent.CountDownLatch;

public class zclient1 {
	private static byte[] toByteArray (final String i) throws IOException {
	return i.getBytes();
	}
	
	public static void main(String[] args) throws Exception {
	final CountDownLatch connectedSignal = new CountDownLatch(1);
	ZooKeeper zoo = new ZooKeeper("localhost:2181",5000,null);
	String path = "/clients/client1";
	Scanner sc = new Scanner(System.in);
	System.out.println("write something here: ");
	String txt = sc.nextLine();
	byte[] ar = toByteArray(txt);
	zoo.create("/clients", null, ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT); //this should be run once time to create parent node for the other sub nodes, otherwise it will complain that showing node exists because persistent
	zoo.create(path, ar, ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.EPHEMERAL);
	Watcher w = new Watcher() {
		public void process(WatchedEvent event) {
			try {
				for (String s: zoo.getChildren("/clients",this, null)) {
					s = "/clients" + "/"+ s;
					if (zoo.exists(s, this) != null) {
						System.out.println("this client there" + " " +  s);
					}else {
						System.out.println("showing the disconnected clients"+ " "  +  s);
					}
				}
				for (String s: zoo.getChildren("/clients",this, null)) {
					System.out.println(s);
					s = "/clients" + "/"+ s;
					byte[] b = zoo.getData(s,this, null);
					String data = new String(b, "UTF-8");
					System.out.println(data);
				}
				for(String c: zoo.getChildren("/", this,null)) {
					c = "/" + "/" + c;
					if(zoo.exists("/",false) == null) {
						System.out.println("root node does not have any nodes" + c);
					}else {
						System.out.println("root node is having nodes" + c);
					}
				}
				zoo.getChildren("/clients",this, null);
			}catch(Exception e) {	
				}
		}
	};
	
	zoo.getChildren("/clients",w, null);
	zoo.getChildren("/", w, null);
	byte[] bn = zoo.getData(path, null, null);
	String data = new String(bn, "UTF-8");
	System.out.println(data);
	int v = zoo.getSessionTimeout();
	for (String s: zoo.getChildren("/clients",w, null)) {
		if (v == 1000) {
			System.out.println("all clients" + " "+  s);
				}
	}
	connectedSignal.await();
	}
}