public class InterfaceBlogExample{

public static void main(String[] args){
    // Creating hard coded wheels
    DefaultWheels hardCodedWheels = new DefaultWheels();
    // Injecting hard coded wheels
    Car nonMantainableCar = new Car(hardCodedWheels);
    nonMantainableCar.roll();
  //Rolling

  //Using interface
    Wheels defaultWheels = new DefaultWheelsImpl();
    Wheels AwesomeWheelsImpl = new  AwesomeWheelsImpl();
    // New car with default wheels
    MaintainableCar maintainableCar = new MaintainableCar(defaultWheels);
    maintainableCar.roll();
    // Went to the dealer, and decided to change wheels
    maintainableCar.changeWheels(AwesomeWheelsImpl);

    maintainableCar.roll();
  //Car still rolling

}
}

class DefaultWheels{



 public void roll(){
   System.out.println("Let's roll with hard coded wheels!!");
 }

}


// This is a non maintainable car
class Car{

   // This are the default wheels
   private DefaultWheels carWheel;

   Car(DefaultWheels wheels){
     carWheel = wheels;
   }

   void roll(){
     carWheel.roll();
   }

 // at this point, your car is hard coded to use just the default wheels.
 // putting other wheels on it will not work (obviously).
}


class MaintainableCar{

   Wheels wheels;

   MaintainableCar(){}

   MaintainableCar(Wheels wheels){
     this.wheels = wheels;
   }

   void roll(){
     wheels.roll();
   }

   void changeWheels(Wheels newWheels){
     this.wheels = newWheels;
   }

}

interface Wheels{

   void roll();

}

// The same default wheels but now, implementing the Wheels interface
class DefaultWheelsImpl implements Wheels{


   @Override
   public void roll(){
     System.out.println("Let's roll :/ with defult wheels!!");
   }

}

class AwesomeWheelsImpl implements Wheels{

   @Override
   public void roll(){
     System.out.println("Let's ROOOLLL with Awesome Wheels!!");
   }

}