Java 接口

public interface Valuable {
    public double getMoney();
}

interface Protectable {
    public void beProtected();
}

interface A extends Protectable {
    void m();
    void getMoney();
}

abstract class Animal {
    private String name;

    abstract void enjoy();
}

class GoldenMonkey extends Animal implements Valuable, Protectable {
    public double getMoney() {
        return 10000;
    }

    public void beProtected() {
        System.out.println("live in the room");
    }

    public void enjoy() {

    }

    public void test() {
        Valuable v = new GoldenMonkey();
        v.getMoney();
        Protectable p = (Protectable)v;
        p.beProtected();
    }
}

class Hen implements A {
    public void m() {}
    public void beProtected() {}
    public double getMoney() {
        return 1.0;
    }

    public void getMoney() {}

}