public static Constellation getConstellation(Date date) {
   if (date == null) return null;
   int begin = 0, end = 11, mid = 5;
   Calendar cal = Calendar.getInstance();
   cal.setTime(date);
   MonthDay x = MonthDay.of(cal.get(Calendar.MONTH) + 1, cal.get(Calendar.DAY_OF_MONTH));
   int y = 11;
   if (x.isAfter(dates[0])) {
     while (end - begin > 1) {
       if (x.isAfter(dates[mid])) {
         end = mid;
       } else {
         begin = mid;
       }
       mid = (begin + end) / 2;
     }
     y = begin;
   }
   return constellation[y];
 }
/** Created by yy on 11/8/15. */
public class ConstellationUtils {
  private static final MonthDay[] dates =
      new MonthDay[] {
        MonthDay.of(1, 19),
        MonthDay.of(2, 18),
        MonthDay.of(3, 20),
        MonthDay.of(4, 10),
        MonthDay.of(5, 20),
        MonthDay.of(6, 21),
        MonthDay.of(7, 22),
        MonthDay.of(8, 22),
        MonthDay.of(9, 22),
        MonthDay.of(10, 23),
        MonthDay.of(11, 21),
        MonthDay.of(12, 21)
      };
  public static Constellation[] constellation =
      new Constellation[] {
        Constellation.AQUARIUS,
        Constellation.PISCES,
        Constellation.ARIES,
        Constellation.TAURUS,
        Constellation.GEMINI,
        Constellation.CANCER,
        Constellation.LEO,
        Constellation.VIRGO,
        Constellation.LIBRA,
        Constellation.SCORPIO,
        Constellation.SAGITTARIUS,
        Constellation.CAPRICORN
      };

  public static Constellation getConstellation(Date date) {
    if (date == null) return null;
    int begin = 0, end = 11, mid = 5;
    Calendar cal = Calendar.getInstance();
    cal.setTime(date);
    MonthDay x = MonthDay.of(cal.get(Calendar.MONTH) + 1, cal.get(Calendar.DAY_OF_MONTH));
    int y = 11;
    if (x.isAfter(dates[0])) {
      while (end - begin > 1) {
        if (x.isAfter(dates[mid])) {
          end = mid;
        } else {
          begin = mid;
        }
        mid = (begin + end) / 2;
      }
      y = begin;
    }
    return constellation[y];
  }
}