JAVA EE: Java Tutorial : Java abstract class(implements interface by abstract class)

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Java Tutorial : Java abstract class(implements interface by abstract class)

MyClass.java

interface A
{
    void sayWelcome();

    void sayHi();

    void sayBye();
}

/*
 * The abstract class can also be used to provide some
 * implementation of the interface. In such case, the end
 * user may not be forced to override all the methods of the
 * interface.
 */
abstract class B implements A
{

    @Override
    public void sayWelcome()
    {
        System.out.println("Welcome...");
    }

}

public class MyClass extends B
{

    @Override
    public void sayHi()
    {
        System.out.println("Hi...");

    }

    @Override
    public void sayBye()
    {
        System.out.println("Bye...");
    }

}

AbstractClassTest.java

public class AbstractClassTest
{

    public static void main(String[] args)
    {
        A aRef = new MyClass();
        aRef.sayWelcome();
        aRef.sayHi();
        aRef.sayBye();
        
    }

}

Output