// interfaces/Adventure.java
// Multiple interfaces
interface CanFight {
void fight();
}
interface CanSwim {
void swim();
}
interface CanFly {
void fly();
}
class ActionCharacter {
public void fight(){}
}
class Hero extends ActionCharacter implements CanFight, CanSwim, CanFly {
public void swim() {}
public void fly() {}
}
public class Adventure {
public static void t(CanFight x) {
x.fight();
}
public static void u(CanSwim x) {
x.swim();
}
public static void v(CanFly x) {
x.fly();
}
public static void w(ActionCharacter x) {
x.fight();
}
public static void main(String[] args) {
Hero h = new Hero();
t(h); // Treat it as a CanFight
u(h); // Treat it as a CanSwim
v(h); // Treat it as a CanFly
w(h); // Treat it as an ActionCharacter
}
}
- 如果继承一个非接口的类,那么只能继承一个类,其余的基元素必须都是接口。需要将所有的接口名称置于 implements 关键字之后且用逗号分隔。可以有任意多个接口,并可以向上转型为每个接口,因为每个接口都是独立的类型
- 类 Hero 结合了具体类 ActionCharacter 和接口 CanFight、CanSwim 和 CanFly。当通过这种方式结合具体类和接口时,需要将具体类放在前面,后面跟着接口(否则编译器会报错)