使用java.util.Calendar返回间隔天数

核心提示：使用SimpleDateFormat，规定好格式，使用java.util.Calendar返回间隔天数，parser出错即为非法/** * Calculates the number of days between two calendar days in a manner * which is independent

　　使用SimpleDateFormat，规定好格式，parser出错即为非法/** * Calculates the number of days between two calendar days in a manner * which is independent of the Calendar type used. * * @param d1　  The first date. * @param d2　  The second date. * * @return　　  The number of days between the two dates.  Zero is *　　　　　　  returned if the dates are the same, one if the dates are *　　　　　　  adjacent, etc.  The order of the dates *　　　　　　  does not matter, the value returned is always >= 0. *　　　　　　  If Calendar types of d1 and d2 *　　　　　　  are different, the result may not be accurate. */static int getDaysBetween (java.util.Calendar d1, java.util.Calendar d2) {　  if (d1.after(d2)) {  // swap dates so that d1 is start and d2 is end　　　  java.util.Calendar swap = d1;　　　  d1 = d2;　　　  d2 = swap;　  }　  int days = d2.get(java.util.Calendar.DAY_OF_YEAR) -　　　　　　　 d1.get(java.util.Calendar.DAY_OF_YEAR);　  int y2 = d2.get(java.util.Calendar.YEAR);　  if (d1.get(java.util.Calendar.YEAR) != y2) {　　　  d1 = (java.util.Calendar) d1.clone();　　　  do {　　　　　  days += d1.getActualMaximum(java.util.Calendar.DAY_OF_YEAR);　　　　　  d1.add(java.util.Calendar.YEAR, 1);　　　  } while (d1.get(java.util.Calendar.YEAR) != y2);　  }　  return days;}