Program: Example for singleton class using static block.

Since static blocks will be called only once, we can use static blocks to develop singleton class. Below example shows how to create singleton classes using static block. To create singleton class, make constructor as private, so that you cannot create object outside of the class. Create a private static variable of same class type, so that created object will be pointed to this reference. Now create static block, and create object inside static block. Since static block will be called only once, the object will be created only once.

package com.java2novice.staticexmp;

public class MyStaticSingleton {

	public static void main(String a[]){
		MySingleton ms = MySingleton.getInstance();
		ms.testSingleton();
	}
}

class MySingleton{
	
	private static MySingleton instance;
	
	static{
		instance = new MySingleton();
	}
	
	private MySingleton(){
		System.out.println("Creating MySingleton object...");
	}
	
	public static MySingleton getInstance(){
		return instance;
	}
	
	public void testSingleton(){
		System.out.println("Hey.... Instance got created...");
	}
}

Creating MySingleton object...
Hey.... Instance got created...