状态模式

代码如下：

import java.util.Scanner;
public class ZhuangTai {
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner scanner = new Scanner(System.in);
        while (true) {
            int i = scanner.nextInt();
            GuanLi guanLi = new GuanLi();
            switch (i) {
            case 0:
                guanLi.setFruit(new Apple("苹果"));
                System.out.println(guanLi.getFruitName());
                break;
            case 1:
                guanLi.setFruit(new Orange("橘子"));
                System.out.println(guanLi.getFruitName());
                break;
            default:
                break;
            }
        }
    }
}

public class GuanLi {
    private Fruit fruit;

    public void setFruit(Fruit fruit) {
        this.fruit = fruit;
    }

    public String getFruitName() {
        return fruit.getName();
    }
}

public interface Fruit {
    public String getName();
}

public class Apple implements Fruit {
    private String name;

    public Apple(String name) {
        this.name = name;
    }

    @Override
    public String getName() {
        // TODO Auto-generated method stub
        return name;
    }
}

public class Orange implements Fruit {
    private String name;

    public Orange(String name) {
        this.name = name;
    }

    @Override
    public String getName() {
        // TODO Auto-generated method stub
        return name;
    }

}