Create Abstract Class Java

1/. Create A.java

abstract public class A {
    abstract void callme();
   
    // concrete methods are still allowed in abstract classes
    void callmetoo() {
        System.out.println("This is a concrete method.");
    }
}
2/.Create B.java

public class B extends A{
    void callme() {
        System.out.println("B's implementation of callme.");
    }
}
3/.Create Abstract.java

public class AbstractDemo {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
        B b = new B();
        b.callme();
        b.callmetoo();
    }