接口和工厂-蒲公英云

接口和工厂

接口和工厂创建两个接口

一个接口内返回另一个接口类型的方法（类似于组合）

interface Cycle {
    int wheels();
}
interface CycleFactory {
    Cycle factory();
}
class Cycle1 implements Cycle {
    public int wheels() {
        return 2;
    }
}
class CycleFactory1 implements CycleFactory {
    public Cycle factory() {
        return new Cycle1();
    }
}
class Cycle2 implements Cycle {
    public int wheels() {
        return 4;
    }
}
class CycleFactory2 implements CycleFactory {
    public Cycle factory() {
        return new Cycle2();
    }
}
public class interface_and_factory {
    Cycle c1, c2;
    public static void main(String[] args) {
        interface_and_factory i = new interface_and_factory();
        CycleFactory cFactory1 = new CycleFactory1();
        i.c1 = cFactory1.factory();
        CycleFactory cFactory2 = new CycleFactory2();
        i.c2 = cFactory2.factory();
        System.out.println("1号工厂生产一辆车" + i.c1 + " 轮子 = " + i.c1.wheels()); //i.c1是一个内存地址 可通过重写toString方法返回字符串
        System.out.println("2号工厂生产一辆车" + i.c2 + "  轮子 =" + i.c2.wheels());
    }
}