How to Create Singleton Class with Static Inner Class in Java

In this example we will show how to use static inner class to develop singleton class in Java.

Source Code

package com.beginner.examples;

public class StaticInnerSingletonExample {
	 
    public static void main(String[] args){
    	// get singleton instance
        Singleton s = Singleton.getInstance();
        s.test();
    }
}

class Singleton {

    private Singleton() {}

    private static class SingletonInstance {
        private static final Singleton INSTANCE = new Singleton();
    }

    public static Singleton getInstance() {
        return SingletonInstance.INSTANCE;
    }
    
    public void test(){
        System.out.println("It is a singleton example.");
    }
}

Output:

It is a singleton example.