复杂枚举类

package demo.api;

//最常见枚举类
enum Direction3 {
    FRONT, BACK, LEFT, RIGHT;//0,1,2,3...

    @Override
    public String toString() {
        return this.ordinal() + " " + this.name();
    }//若不重写，以下输出结果相同：d1, d1.toString(), d1.name()
}

//最复杂的枚举类
enum Direction2 {
    //Direction2的对象：含有构造方法，且必须实现抽象方法show()
    RIGHT("右") {
        @Override
        void show() {
            System.out.println(getName());
        }
    }, LEFT("左") {
        @Override
        void show() {
            System.out.println(getName());
        }
    }, BACK("后") {
        @Override
        void show() {
            System.out.println(getName());
        }
    }, FRONT("前") {
        @Override
        void show() {
            System.out.println(getName());
        }
    };

    private String name;

    private Direction2(String name) {
        this.name = name;
    }

    String getName() {
        return name;
    }

    abstract void show();
}

class 枚举类 {
    public static void main(String[] args) {
        demo();//最复杂的枚举类演示
//        methodDemo();//简单枚举类方法演示
    }

    //简单枚举类方法演示
    private static void methodDemo() {
        Direction3 d1 = Direction3.FRONT;
        Direction3 d2 = Direction3.BACK;
        Direction3 d3 = Direction3.LEFT;
        Direction3 d4 = Direction3.RIGHT;
        System.out.println(d1);
        System.out.println(d1 + "比" + d2 + "大：" + d1.compareTo(d2));
        System.out.println(d1 + "的名字是：" + d1.name());
        System.out.println(d1 + "序数: " + d1.ordinal());
        System.out.println("toString()重写：" + d1.toString());

        //从Direction3.class中拿到字节码文件，并从中找到名字为FRONT 的对象返回出来
        Direction3 d = Enum.valueOf(Direction3.class, "FRONT");
        System.out.println(d.name());

        //遍历枚举
        System.out.println("遍历枚举:");
        Direction3[] direction3s = Direction3.values();//返回枚举对象数组
        for (Direction3 dd : direction3s) {
            System.out.println(dd.name());
        }
    }

    //最复杂的枚举类演示
    private static void demo() {
        Direction2 d = Direction2.FRONT;
        System.out.println("输出枚举对象: " + d);
        System.out.println("枚举对象的自定义方法 : " + d.getName());
        System.out.print("枚举对象中的方法: ");
        d.show();

        //switch语句中的枚举
        switch (d) {
            case FRONT:
                System.out.println("你选择了前");
                break;
            case BACK:
                System.out.println("你选择了后");
                break;
            case LEFT:
                System.out.println("你选择了左");
                break;
            case RIGHT:
                System.out.println("你选择了右");
                break;
            default:
        }
    }
}
/**
 * //知道枚举的下标，得到枚举的对象和名称
 * int idx2 = 2;
 * //得到枚举的对象
 * Color100[] cs = Color100.values();
 * //根据下标得到对象
 * Color100 c12 = cs[idx2];
 * //得到枚举的名称
 * String name = c12.name();
 * System.out.println(name);
 */