java根据日期获得星期常用方法

本文转自：http://blog.163.com/namira@126/blog/static/2243844520092159527996/

 

http://aidejiepai.spaces.live.com/Blog/cns!B3E72DC93EF7946B!140.entry

    /**
     * 根据日期获得星期
     * @param date
     * @return
     */
public static String getWeekOfDate(Date date) {
  String[] weekDaysName = { "星期日", "星期一", "星期二", "星期三", "星期四", "星期五", "星期六" };
  String[] weekDaysCode = { "0", "1", "2", "3", "4", "5", "6" };
  Calendar calendar = Calendar.getInstance();
  calendar.setTime(date);
  int intWeek = calendar.get(Calendar.DAY_OF_WEEK) - 1;
  return weekDaysCode[intWeek];
}
/**
  * 获得周一的日期
  *
  * @param date
  * @return
  */
public static String getMonday(Date date) {

  Calendar calendar = Calendar.getInstance();

  calendar.setTime(date);

  calendar.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);

  return dateFormat.format(calendar.getTime());

}
/**
  * 获得周三的日期
  *
  * @param date
  * @return
  */
public static String getWednesday(Date date) {

  Calendar calendar = Calendar.getInstance();

  calendar.setTime(date);

  calendar.set(Calendar.DAY_OF_WEEK, Calendar.WEDNESDAY);

  return dateFormat.format(calendar.getTime());

}
    /**
  * 获得周五的日期
  *
  * @param date
  * @return
  */
public static String getFriday(Date date) {

  Calendar calendar = Calendar.getInstance();

  calendar.setTime(date);

  calendar.set(Calendar.DAY_OF_WEEK, Calendar.FRIDAY);

  return dateFormat.format(calendar.getTime());
}

/**
  * 当前日期前几天或者后几天的日期
  * @param n
  * @return
  */ 
public static String afterNDay(int n) {

  Calendar calendar = Calendar.getInstance();

  calendar.setTime(new Date());

  calendar.add(Calendar.DATE, n);

  Date date = calendar.getTime();

  String s = dateFormat.format(date);

  return s;

}
/**
  * 判断两个日期是否在同一周
  *
  * @param date1
  * @param date2
  * @return
  */
public static boolean isSameWeekDates(Date date1, Date date2) {
  Calendar cal1 = Calendar.getInstance();
  Calendar cal2 = Calendar.getInstance();
  cal1.setTime(date1);
  cal2.setTime(date2);
  int subYear = cal1.get(Calendar.YEAR) - cal2.get(Calendar.YEAR);
  if (0 == subYear) {
   if (cal1.get(Calendar.WEEK_OF_YEAR) == cal2
     .get(Calendar.WEEK_OF_YEAR))
    return true;
  } else if (1 == subYear && 11 == cal2.get(Calendar.MONTH)) {
   // 如果12月的最后一周横跨来年第一周的话则最后一周即算做来年的第一周
   if (cal1.get(Calendar.WEEK_OF_YEAR) == cal2
     .get(Calendar.WEEK_OF_YEAR))
    return true;
  } else if (-1 == subYear && 11 == cal1.get(Calendar.MONTH)) {
   if (cal1.get(Calendar.WEEK_OF_YEAR) == cal2
     .get(Calendar.WEEK_OF_YEAR))
    return true;
  }
  return false;
}