Singleton Class using private constructor

singleton.java

import java.io.*;

class singletonExample
{
	public static singletonExample obj = null;
	private singletonExample()
	{
		System.out.println("Created object");
	}
	public static singletonExample createObject()
	{
		if(obj == null)
		{
			obj = new singletonExample();
		}
			return obj;
	}
}

public class test
{
	public static void main(String args[])
	{
		singletonExample ob1 = singletonExample.createObject();
		singletonExample ob2 = singletonExample.createObject();
		singletonExample ob3 = singletonExample.createObject();
	}
}