Java面向对象接口的应用实例练习

interface USB
{
    public void open();
    public void close();
}

class Upan implements USB
{
    public void open()
    {
        System.out.println("Upan open");
    }
    public void close()
    {
        System.out.println("Upan close");
    }
}

class USBMouse implements USB
{
    public void open()
    {
        System.out.println("USBMouse open");
    }
    public void close()
    {
        System.out.println("USBMouse close");
    }
}

class BookPC
{
    public static void main(String[] args)
    {
        useUSB(new Upan());
        useUSB(new USBMouse());
    }
    public static void useUSB(USB u)
    {
        u.open();
        u.close();
    }
}