How do I extend an abstract inner class?

Extending an abstract inner class in java

In the earlier posts, I mentioned about inner classes. For the reference we can see in the below link.

http://www.javatechtipssharedbygaurav.com/2013/05/inner-classes-in-java.html

For extending an abstract inner class we have few approaches:-

We can extend abstract inner class in following ways

Example to extend abstract inner class

AbstractNonStaticInnerClass.java

package com.gaurav.corejava.innerclass;

public class AbstractNonStaticInnerClass {
    private int secondNumber = 10;

    public int getCalculatedValue() {
        SubNonStaticInnerClass nsic = new SubNonStaticInnerClass();
        int firstNumber = nsic.getFirstNumber();
        return firstNumber + secondNumber;
    }

    abstract class NonStaticInnerClass {
        int firstNum = 20;

        public abstract String getName();

        public String strNonStInVar = "MYSELF NON STATIC INNER CLASS VARIABLE ";

        public int getFirstNumber() {

            return firstNum;
        }

    }

    class SubNonStaticInnerClass extends NonStaticInnerClass {
        String name = "ARYAN GAURAV";

        public String getName() {
            return name;
        }
    }

    public static void main(String args[]) {

        // FIRST WAY TO CREATE AN INSTANCE OF NON STATIC INNER CLASS

        AbstractNonStaticInnerClass nsictd = new AbstractNonStaticInnerClass();
        AbstractNonStaticInnerClass.NonStaticInnerClass nonStaticInner = nsictd.new SubNonStaticInnerClass();
        System.out.println("******************************************");
        System.out
                .println("GETTING FIRST NUMBER FROM NON STATIC INNER CLASS :- "
                        + nonStaticInner.getFirstNumber());
        System.out.println("GETTING CALCULATED VALUE :- "
                + nsictd.getCalculatedValue());

        // SECOND WAY TO CREATE AN INSTANCE OF NON STATIC INNER CLASS
        System.out.println("\n******************************************");
        AbstractNonStaticInnerClass.NonStaticInnerClass nonstInner = (new AbstractNonStaticInnerClass()).new SubNonStaticInnerClass();
        System.out
                .println("GETTING FIRST NUMBER FROM NON STATIC INNER CLASS WITH SECOND APPROACH :- "
                        + nonstInner.getFirstNumber());
        System.out
                .println("GETTING STRING VALUE FROM NON STATIC INNER CLASS WITH SECOND APPROACH :- "
                        + nonstInner.strNonStInVar);
        System.out
                .println("CALLING METHOD OF SUB CLASS NON STATIC INNER CLASS-"
                        + nonstInner.getName());
    }
}

Result:-

******************************************
GETTING FIRST NUMBER FROM NON STATIC INNER CLASS :- 20
GETTING CALCULATED VALUE :- 30

******************************************
GETTING FIRST NUMBER FROM NON STATIC INNER CLASS WITH SECOND APPROACH :- 20
GETTING STRING VALUE FROM NON STATIC INNER CLASS WITH SECOND APPROACH :- MYSELF NON STATIC INNER CLASS VARIABLE
CALLING METHOD OF SUB CLASS NON STATIC INNER CLASS-ARYAN GAURAV

Example to extend abstract inner class using second way i.e Anonymous class

CallAbstractNonStaticInnerClass.java

package com.gaurav.corejava.innerclass;

public class CallAbstractNonStaticInnerClass {
    private int secondNumber = 10;

    abstract class NonStaticInnerClass {
        int firstNum = 20;

        public abstract String getName();

        public String strNonStInVar = "MYSELF ABSTRACT NON STATIC INNER CLASS VARIABLE ";

        public int getCalculatedNumber() {

            return firstNum + secondNumber;
        }

    }

}

ExtendAbstractNonStaticInnerClass.java

package com.gaurav.corejava.innerclass;


public class ExtendAbstractNonStaticInnerClass {

    public static void main(String args[]){
    CallAbstractNonStaticInnerClass.NonStaticInnerClass nest = (new CallAbstractNonStaticInnerClass()).new NonStaticInnerClass(){

        @Override
        public String getName() {
            System.out.println("INSIDE GETNAME() METHOD WHICH IS ABSTRACT METHOD IN NON STATIC INNER CLASS");
            return "GAURAV";
        }};
        System.out.println("THE STRING VALUE RETURNED BY GETNAME METHOD IS : - "+nest.getName());
        System.out.println("ACCESSING INT VARIABLE OF THE ABSTRACT INNER CLASS :- "+nest.firstNum);
        System.out.println("ACCESSING STRING VARIABLE OF THE ABSTRACT INNER CLASS :- "+nest.strNonStInVar);
        System.out.println("ACCESSING GETCALCULATEDNUMBER METHOD OF THE ABSTRACT INNER CLASS :-"+nest.getCalculatedNumber());
    }

   
}

Result:-

INSIDE GETNAME() METHOD WHICH IS ABSTRACT METHOD IN NON STATIC INNER CLASS
THE STRING VALUE RETURNED BY GETNAME METHOD IS : - GAURAV
ACCESSING INT VARIABLE OF THE ABSTRACT INNER CLASS :- 20
ACCESSING STRING VARIABLE OF THE ABSTRACT INNER CLASS :- MYSELF ABSTRACT NON STATIC INNER CLASS VARIABLE
ACCESSING GETCALCULATEDNUMBER METHOD OF THE ABSTRACT INNER CLASS :-30