Interfaces and Abstract Classes

gistfile1.java

public interface Drivable
{
    public void drive();
}

public abstract Plane implements Drivable
{
    @Override
    public void drive()
    {
        // drive in a plane sort of way
    }
}

public abstract Car implements Drivable
{
    boolean fuelEmpty = false;
    
    @Override
    public void drive()
    {
        useFuel();
        goForward();
    }
    
    public void goForward()
    {
        /* use wheels and stuff */
    }
    
    public boolean isFuelEmpty()
    {
        return fuelEmpty;
    }
    
    public boolean setFuelEmpty(boolean empty)
    {
        fuelEmpty = empty;
    }
    
    public abstract void useFuel();
}

public class DiesalCar extends Car
{
    @Override
    public void useFuel()
    {
        /* use fuel in a diesal way */
        setEmpty(true);
    }
}

public class PetrolCar extends Car
{
    @Override
    public void useFuel()
    {
        /* use fuel in a diesal way */
        setEmpty(true);
    }
}

public class SolarPanelCar extends Car
{
    @Override
    public void useFuel()
    {
        /* use solar panel */
    }
}

// as for usage of implements

public void PhysicsHandler
{
    public static driveVehicle(Drivable drivableVehicle)
    {
        drivableVehicle.drive();
    }
    
    public static driveCar(Car car)
    {
        car.drive();
    }
}