enumeration（枚举）是JDK1.5引入的新特性，放在java.lang包中。
1、枚举类方法介绍
package com.enums;
public class TestEnum {
public static void main(String[] args) {
Season season = Season.autumn;
System.out.println(season);//autumn
System.out.println(season.compareTo(Season.autumn));//
System.out.println(season.compareTo(Season.spring));//
System.out.println(season.getDeclaringClass());//class com.enums.TestEnum$Season
System.out.println(Season.autumn.name());//autumn
System.out.println(Season.autumn.ordinal());//
System.out.println(Season.autumn.toString());//autumn
System.out.println(Season.valueOf(Season.class, "autumn"));//autumn
}
/**
* int compareTo(E o) 比较此枚举与指定对象的顺序，返回值为枚举与指定对象的序号差。
* Class<E> getDeclaringClass() 返回与此枚举常量的枚举类型相对应的 Class 对象。
* String name() 返回此枚举常量的名称，在其枚举声明中对其进行声明。
* int ordinal() 返回枚举常量的序数（它在枚举声明中的位置，其中初始常量序数为零）。
* String toString() 返回枚举常量的名称，它包含在声明中。
* static <T extends Enum<T>> T valueOf(Class<T> enumType, String name) 返回带指定名称的指定枚举类型的枚举常量。
*
* @author Administrator
*
*/
public enum Season {
spring, summer, autumn, winter;
}
}
2、遍历枚举
package com.enums;
public class TestEnum1 {
public static void main(String[] args) {
for(Season s : Season.values()){
System.out.println(s);
}
}
public enum Season {
spring, summer, autumn, winter;
}
}
3、枚举值作为switch条件值
package com.enums;
public class TestEnum2 {
public static void main(String[] args) {
Season season = Season.autumn;
switch (season) {
case spring:
System.out.println("春天");
break;
case summer:
System.out.println("夏天");
break;
case autumn:
System.out.println("秋天");
break;
case winter:
System.out.println("冬天");
break;
}
}
public enum Season {
spring, summer, autumn, winter;
}
}
4、枚举中定义变量和方法
package com.enums;
public class TestEnum3 {
public static void main(String[] args) {
System.out.println(Season.autumn.getName());//秋天
}
public enum Season {
spring("春天"), summer("夏天"), autumn("秋天"), winter("冬天");
private String name;
private Season(String name){
this.name = name;
}
public String getName() {
return name;
}
}
}
详细原理请参考: