如何表示一周的开始、结束时间字的符串表示形式如：yyyyMMdd

1、获取一周的周一开始字符串表示：

    public static String getFirstDayOfWeek(){

   SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd");
   Calendar cal = Calendar.getInstance();
   int dayWeek = cal.get(Calendar.DAY_OF_WEEK);
   if (1 == dayWeek) {
      cal.add(Calendar.DAY_OF_MONTH, -1);
   }
   cal.setFirstDayOfWeek(Calendar.MONDAY);
   int day = cal.get(Calendar.DAY_OF_WEEK);
   cal.add(Calendar.DATE, cal.getFirstDayOfWeek() - day);
   String imptimeBegin = sdf.format(cal.getTime());
   return imptimeBegin;
}

2、获取一周的最后一天的字符串表示：

public static String getLastDayOfWeek(){
   Calendar c = Calendar.getInstance();
   int day_of_week = c.get(Calendar.DAY_OF_WEEK) - 1;
   if (day_of_week == 0)
      day_of_week = 7;
   c.add(Calendar.DATE, -day_of_week + 7);
   SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd");
   return sdf.format(c.getTime());
}