CONCRETE CLASS IN JAVA

Concrete class implements all the operations of an object. It is created using the keyword class. It contains only concrete methods including variables, blocks and constructors. It is always created as sub class next to abstract class or interface in object’s inheritance hierarchy. A method that has body is called as concrete method. The modifiers allowed for a concrete class are – public, final, abstract, strictfp.

Example –

abstract class Bus{

          public abstract void engine();

          public void brakes()

          {

                   System.out.println("Bus has two brakes");

          }

}

class RedBus extends Bus{

          @Override

          public void engine() {

                   System.out.println("Red bus engine capacity is 40 kmph");

          }

}

class Volve extends Bus{

          @Override

          public void engine() {

                   System.out.println("Volve engine capacity is 110 kmph");                  

          }       

}

class Driver{

          public void assignBus(Bus b)

          {

                   b.brakes();

                   b.engine();

          }

}

class Tesr1 {

          public static void main(String[] args) {

                   Driver d = new Driver();

                   d.assignBus(new Volve());

                   Driver d2 = new Driver();

                   d2.assignBus(new RedBus());                

          }       

}

Output –

Bus has two brakes

Volve engine capacity is 110 kmph

Bus has two brakes

Red bus engine capacity is 40 kmph