一、枚举类型的使用规范

阿里巴巴Java开发手册中对enum类型的使用说明：

对enum类的命名说明：

对枚举类型的使用限制：

对枚举类型的强制注释：

二、通过demo认识枚举

Season.java
一个包含枚举的普通类

package com.jake.guidelines.enums; 
 
public class Season { 
 
    SeasonEnums seasonEnum; 
 
    public enum SeasonEnums { 
        SPRING(1), SUMMER(2), AUTUMN(3), WINTER(4); 
 
        private int seq; 
 
        SeasonEnums(int seq){ 
            this.seq = seq; 
            System.out.println("The season-enum constructor is invoked, and the seq = " + seq); 
        } 
    } 
 
    public static void printSeasonVerses(SeasonEnums seasonEnums) { 
        switch (seasonEnums) { 
            case SPRING: 
                System.out.println("春风又绿江南岸"); 
                break; 
            case SUMMER: 
                System.out.println("但惜夏日长"); 
                break; 
            case AUTUMN: 
                System.out.println("天气晚来秋"); 
                break; 
            case WINTER: 
                System.out.println("疑是经冬雪未销"); 
                break; 
        } 
    } 
} 
 

SeasonEnumTest.java
枚举测试类

package com.jake.guidelines.enums; 
 
import org.junit.Test; 
 
public class SeasonEnumTest { 
 
    @Test 
    public void testSeasonEnum() { 
        System.out.println(Season.SeasonEnums.SPRING); 
    } 
 
    @Test 
    public void testSeasonEnumValue() { 
        System.out.println(Season.SeasonEnums.valueOf("SPRING")); 
    } 
 
    @Test 
    public void testSeasonEnumValues() { 
        for (Season.SeasonEnums season : Season.SeasonEnums.values()) { 
            System.out.println(season.name()); 
        } 
    } 
 
    @Test 
    public void testSeasonEnumOrdinate() { 
        Season.SeasonEnums winter = Season.SeasonEnums.WINTER; 
        System.out.println(winter.ordinal()); 
    } 
 
    @Test 
    public void testSeasonEnumField() { 
        Season season = new Season(); 
        season.seasonEnum = Season.SeasonEnums.SUMMER; 
        System.out.println(season.seasonEnum.name()); 
 
    } 
 
    @Test 
    public void testSeasonEnumsInSwitchCases() { 
        Season.printSeasonVerses(Season.SeasonEnums.SPRING); 
    } 
}