Question

我正在创建一个界面说“汽车”

public interface Car {
    public void drive(int Speed, int Gear ); // for cars which have gears
    public void drive(int Speed); // for cars which do not have gears
}

现在我正在创建我的实施课程，说SimpleCar和AdvanceCar

SimpleCar没有齿轮
AdvanceCar有齿轮

现在，当我编写实现类时，我被迫为这两种方法编写代码，即使我不想在实现类中使用它们

public class SimpleCar implements Car {
    public void drive(int Speed, int Gear ){ ... }; // dont want this method in SimpleCar
    public void drive(int Speed ){ ... };
}

有人可以帮我设计一个有方法但实现类有不同签名的界面吗？

Answer 1

public interface Car {

    public void drive(int Speed, int Gear); // for cars which have gears

    public void drive(int Speed); // for cars which do not have gears
}



public class CarAdapter implements Car {

    @Override
    public void drive(int Speed, int Gear) {
        // TODO Auto-generated method stub

    }

    @Override
    public void drive(int Speed) {
        // TODO Auto-generated method stub

    }

}


public class AdvancedCar extends CarAdapter {

    @Override
    public void drive(int Speed) {
        // TODO Auto-generated method stub
        super.drive(Speed);
    }

    @Override
    public void drive(int Speed, int Gear) {
        // TODO Auto-generated method stub
        super.drive(Speed, Gear);
    }

}


public class SimpleCar extends CarAdapter {

    @Override
    public void drive(int Speed) {
        // TODO Auto-generated method stub
        super.drive(Speed);
    }


}

Answer 2

您应该有一个Car接口和另一个名为GearCar的接口，它扩展了Car接口。

这样您就可以实现GearCar or Car接口。

Answer 3

参见以下设计。我已根据您的要求从gear接口原因删除了Car，因为它对所有汽车无效，因此无法成为界面的一部分。

public interface Car 
{     
    // public void drive(int Speed, int Gear ); // for cars which have gears     
    public void drive(int Speed); // for cars which do not have gears 
}

public abstract class SimpleCar implements Car
{
    public void drive(int speed) { ... }
    public abstract void accelerate(); // you can move it to interface also
}

public abstract class AdvancedCar implements Car
{
    protected int CURRENT_GEAR = 1;
    public void drive(int speed) { ... }
    public void changeGear(int gear) { ... }
    public abstract void accelerate();
}

public class Reva extends SimpleCar
{
    // provide implementation for accelerate
}

public class Ferrari extends AdvancedCar
{
    // provide implementation for accelerate
}

Answer 4

编写一个CarAdapter，在接口中提供所有方法的空实现。然后让您的SimpleCar扩展CarAdapter（默认情况下会Car）

这在Swing应用程序中经常出现。

Answer 5

只需删除需要Gear的方法声明，因为在您的类中，您需要实现在您实现的接口中声明的每个方法，除非您的类本身是抽象的。

如果您不想实现接口的任何方法，那么您应该将SimpleCar和AdvancedCar作为抽象类。

Answer 6

public interface Vehicle {
    public void drive(int Speed);
}

public interface Car extends Vehicle{
    public void drive(int Speed, int Gear ); 
}

public class SimpleCar implements Vehicle {
    public void drive(int Speed ){ ... };
}

public class AdvancedCar implements Car {
    public void drive(int Speed, int Gear ){ ... };
    public void drive(int Speed ){ ... };
}

具有不同签名的多个实现类的java接口

6 个答案: