Simple Inheritance

public class HelloWorld{

    public static void main(String args[]){

        Greet msg=new Greet();

        System.out.println(msg.getMessage());

        System.out.println(msg.getThankYou());

        msg.getMyMessage();

    }

}

public class Greet extends Message{

       private String msg=new String("Computer Science - ");

       public Greet(){

           super();

        }

    public String getMessage(){

        return msg+getWord();

    }

}

public class Message extends Goodbye implements Welcome {

       private String word;

       public Message(){

           System.out.println("Did you just call me?");

           word="Hello World";

        }

    public final String getWord(){   //try to override this in message

        return word;

    }

    public void greetMe(String m){

        System.out.println("Welcome to my application");

    }

    public String getThankYou() {

        return thanks;

    }

}

public abstract class Goodbye{

    protected String thanks="Thank you for visiting us";

    public abstract String getThankYou();

    public void getMyMessage(){

        System.out.println("This is from the abstract class");

    }

}

public interface Welcome{

    void greetMe(String m);

    //only default and public class modifier can be used

    //try to copy a method with body - fail

}