AbstractClassAndConstructor

/**
 *  Can abstract class Has constructor ? If yes, how one can call the default constructor / Overloaded contructor
 *  
 *  Reasons : Why abstract  class has constructor
 *  
 *  Purpose of the constructor is to initialize the value of the field if an abstract class has the field.
 *  Constructor are not used to create the object that is the misconception most of the people have.
 *  
 *  (1) you have defined final fields in the abstract class but you did not initialize them in the declaration itself;
 *   in this case, you MUST have a constructor to initialize these fields
 *   
 *   (2) If you want to initialize the abstract class field to some default value for every subclass in that case also 
 *   We need the abstract class constructor. 
 *  
 *  
 */
package com.mypractice.github;

public class MyApp1 extends MyAbstractClass
{
	public MyApp1() 
	{
		super();
		//super(7,9);
		System.out.println("MyApp1 default CTOR");
	}
	
	public static void main(String[] args)
	{
		MyApp1 ma1 = new MyApp1();
		ma1.myMethod1();
		ma1.myMethod2();
	}

	@Override
	void myMethod1() {
		System.out.println("Abstract class method : myMethod1() implementation");
	}
}

abstract class MyAbstractClass
{
	private int i;
	private int j;
	
	public MyAbstractClass() {
		System.out.println("Default CTOR of abstract class");
	}
	
	public MyAbstractClass(int i, int j)
	{
		this.i = i;
		this.j = j;
		System.out.println("Overloaded CTOR of abstract class");
	}
	
	abstract void myMethod1();
	
	void myMethod2()
	{
		System.out.println("This is concret method myMethod2()");
	}
}