接口的上溯造型——《Thinking in Java》随笔015

//: Adventure.java
package cn.skyfffire;

/**
 * 
 * @author skyfffire
 *
 * 此类用于研究接口的上溯造型
 */
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 {
    
    @Override
    public void fight() {
        System.out.println("fight function run.");
    }
    
    @Override
    public void swim() {
        System.out.println("swim function run.");
    }
    
    @Override
    public void fly() {
        System.out.println("fly function run.");
    }
}

public class Adventure {
    static void t(CanFight x) {
        x.fight();
    }
    
    static void u(CanSwim x) {
        x.swim();
    }
    
    static void v(CanFly x) {
        x.fly();
    }
    
    static void w(ActionCharacter x) {
        x.fight();
    }
    
    public static void main(String[] args) {
        Hero i = new Hero();
        
        t(i);
        u(i);
        v(i);
        w(i);
    }
}

///:~

可以发现，类/抽象类/接口 都可以进行上溯造型，而且实现多个接口的类可以对任意一个接口进行上溯造型