java接口用法

1、在接口中的任何成员都是static和final的，接口就成为便捷的创建产量组的工具。
public interface Months {
  int
    JANUARY = 1, FEBRUARY = 2, MARCH = 3,
    APRIL = 4, MAY = 5, JUNE = 6, JULY = 7,
    AUGUST = 8, SEPTEMBER = 9, OCTOBER = 10,
    NOVEMBER = 11, DECEMBER = 12;
}
接口中的数据成员自动是public的。
如何引用：如果不在同一个包里面，则要先导入接口所在的包，然后用Months.JANUARY表达式就可以来引用它的值。