java 带构造方法的枚举

例：

public class EnumTest {

   public static void main(String[] args){

      WeekDay weekDay =WeekDay.FRI;

  System.out.println(weekDay);

  System.out.println(weekDay.name());

  System.out.println(weekDay.ordinal());

  System.out.println(WeekDay.valueOf("SUN"));

  System.out.println(WeekDay.values().length);

 }

   public enum WeekDay{

  //其他元素置于枚举之后

 //SUN(1),执行的是第二个构造方法，MON()或MON执行第一个构造方法

  SUN(1),MON(),TUE,WED,THI,FRI,SAT;

  private WeekDay(){System.out.println("first");}

  private WeekDay(int day){System.out.println("second");}

 }

}

运行结果：

second
first
first
first
first
first
first
FRI
FRI
5
SUN
7