【Java】-NO.16.EBook.4.Java.1.005-【疯狂Java讲义第3版 李刚】- 枚举

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Tittle：【Java】-NO.16.EBook.4.Java.1.005-【疯狂Java讲义第3版 李刚】- 枚举

Style：EBook

Series：Java

Since：2017-09-18

End：....

Total Hours：...

Degree Of Diffculty：2

Degree Of Mastery：2

Practical Level：2

Desired Goal：2

Archieve Goal：....

Gerneral Evaluation：...

Writer:kingdelee

Related Links：

http://www.cnblogs.com/kingdelee/

package com.lee.test.java.ebook.crazy_java.u_6_oop_2.c_6_9_emnu;

public class MyEmunTest {

    // 1. 最简单的枚举类定义方式
    enum Season {
        SPRING, SUMMER, FALL, WINTER;
    }

    // 2. 定义枚举时，应把成员变量赋值为 final 以免可以直接通过 .var赋值修改
    // 2.1 枚举应有构造方法指定成员变量，其枚举对象隐式为 public static final 类型 = new ..("");
    // 2.2 枚举类中的枚举值实际上是匿名子类的实例
    enum Gender {
        MALE("男"), FAMALE("女");
        private final String name;

        Gender(String name) {
            this.name = name;
        }
    }

    interface Show{
        void show();
    }

    // 2.3 枚举类实现接口时，每个枚举值都要实现接口
    enum AA implements Show{
        SPRING {
            // 2.3 枚举类中定义的抽象方法，每个枚举值都需要实现
            @Override
            public void mustAction() {
                System.out.println("mustAction");
            }

            // 2.3 枚举类实现接口时，每个枚举值都要实现接口
            @Override
            public void show() {
                System.out.println("show");
            }
        }, SUMMER {
            // 2.3 枚举类中定义的抽象方法，每个枚举值都需要实现
            @Override
            public void mustAction() {
                System.out.println("mustAction");
            }

            // 2.3 枚举类实现接口时，每个枚举值都要实现接口
            @Override
            public void show() {
                System.out.println("show");
            }
        };

        // 2.3 枚举类中定义的抽象方法，每个枚举值都需要实现
        public abstract void mustAction();
    }

    public static void main(String[] args) {

        for (Season season : Season.values()) {
            if (Season.SPRING == season) {
                System.out.println(season.name());
            }
        }

        Gender male = Enum.valueOf(Gender.class, "MALE");
        // 报错
//        Gender male = Enum.valueOf(Gender.class, "男");
        System.out.println(male == Gender.MALE);

        System.out.println(male.name);

        AA spring = AA.SPRING;

    }

}

　　

import java.util.HashMap;
import java.util.Map;

/**
 * 模拟星期中的表示的天，每个星期天都表示一个对象
 * 1、类中的每一个枚举成员都是该类的一个实例对象
 * 2、构造函数私有化
 * 3、提供操作枚举成员的抽象方法和静态方法
 */
public abstract class WeekDate {
	/**
	 * 星期一
	 */
	public static final WeekDate MON = new WeekDate("MON",0) {//匿名子类
		@Override
		public WeekDate nextDay() {
			return TUES;
		}
		@Override
		public WeekDate preDay() {
			return SUN;
		}
		@Override
		public String toString() {
			return "WeekDate.MON";
		}
	};	

	/**
	 * 星期二
	 */
	public static final WeekDate TUES = new WeekDate("TUES",1) {
		@Override
		public WeekDate nextDay() {
			return WEDNES;
		}
		@Override
		public WeekDate preDay() {
			return MON;
		}
		@Override
		public String toString() {
			return "WeekDate.TUES";
		}
	};

	/**
	 * 星期三
	 */
	public static final WeekDate WEDNES = new WeekDate("WEDNES",2) {
		@Override
		public WeekDate nextDay() {
			return THURS;
		}
		@Override
		public WeekDate preDay() {
			return TUES;
		}
		@Override
		public String toString() {
			return "WeekDate.WEDNES";
		}
	};

	/**
	 * 星期四
	 */
	public static final WeekDate THURS = new WeekDate("THURS",3) {
		@Override
		public WeekDate nextDay() {
			return FRI;
		}
		@Override
		public WeekDate preDay() {
			return WEDNES;
		}
		@Override
		public String toString() {
			return "WeekDate.THURS";
		}
	};

	/**
	 * 星期五
	 */
	public static final WeekDate FRI = new WeekDate("FRI",4){
		@Override
		public WeekDate nextDay() {
			return SATUR;
		}
		@Override
		public WeekDate preDay() {
			return THURS;
		}
		@Override
		public String toString() {
			return "WeekDate.FRI";
		}
	};

	/**
	 * 星期六
	 */
	public static final WeekDate SATUR = new WeekDate("SATUR",5){
		@Override
		public WeekDate nextDay() {
			return SUN;
		}
		@Override
		public WeekDate preDay() {
			return FRI;
		}
		@Override
		public String toString() {
			return "WeekDate.SATUR";
		}
	};

	/**
	 * 星期日
	 */
	public static final WeekDate SUN = new WeekDate("SUN",6){
		@Override
		public WeekDate nextDay() {
			return MON;
		}
		@Override
		public WeekDate preDay() {
			return SATUR;
		}
		@Override
		public String toString() {
			return "WeekDate.SUN";
		}
	};

	private static Map<String, WeekDate> valueMap = new HashMap<String, WeekDate>();

	/**
	 * 枚举名称
	 */
	private final String name;

	/**
	 * 枚举成员的顺序
	 */
	private final int ordinal;

	private WeekDate(String name,int ordinal) {
		this.name = name;
		this.ordinal = ordinal;
	}

	/**
	 * 保存枚举成员
	 */
	private static WeekDate[] values = {
		MON,TUES,WEDNES,THURS,FRI,SATUR,SUN
	};

	//初始化
	static {
		valueMap.put("MON", values[0]);
		valueMap.put("TUES", values[1]);
		valueMap.put("WEDNES", values[2]);
		valueMap.put("THURS", values[3]);
		valueMap.put("FRI", values[4]);
		valueMap.put("SATUR", values[5]);
		valueMap.put("SUN", values[6]);
	}

	/**
	 * 下一天
	 * @return
	 */
	public abstract WeekDate nextDay();

	/**
	 * 前一天
	 * @return
	 */
	public abstract WeekDate preDay();

	/**
	 * 枚举中的所有成员
	 * @return
	 */
	public static WeekDate[] values() {
		return values;
	}

	/**
	 * 将一个字符串转换成一个枚举成员对象
	 * @param name 枚举名称
	 * @return 枚举对象
	 */
	public static WeekDate valueOf(String name) {
		if (name.equalsIgnoreCase("MON")) {
			return MON;
		} else if (name.equalsIgnoreCase("TUES")) {
			return TUES;
		} else if (name.equalsIgnoreCase("WEDES")) {
			return WEDNES;
		} else if (name.equalsIgnoreCase("THURS")) {
			return THURS;
		} else if (name.equalsIgnoreCase("FRI")) {
			return FRI;
		} else if (name.equalsIgnoreCase("SATUR")) {
			return SATUR;
		} else if (name.equalsIgnoreCase("SUN")) {
			return SUN;
		} else {
			throw new IllegalArgumentException("找不到" + name + "枚举类型！");
		}
	}

	/**
	 * 优化字符串转枚举对象
	 * @param name 枚举名称
	 * @return 枚举对象
	 */
	public static WeekDate valueOf_2(String name) {
		WeekDate value = valueMap.get(name.toUpperCase());
		if (value == null) {
			throw new IllegalArgumentException("找不到" + name + "枚举类型！");
		}
		return value;
	}
	public String getName() {
		return name;
	}
	public int getOrdinal() {
		return ordinal;
	}
}