获取最近的上一个周五方法案例

public static Calendar getCurrentDay(String dataTime ,int weekDay){   Calendar calendar = Calendar.getInstance();   try {      int i =dayForWeek(dataTime);      SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");      calendar.setTime(format.parse(dataTime));      if(i>=weekDay&&i<7){         calendar.set(Calendar.DAY_OF_WEEK, weekDay+1);         calendar.set(calendar.get(Calendar.YEAR), calendar.get(Calendar.MONTH),               calendar.get(Calendar.DATE), 0, 0, 0);         calendar.set(Calendar.MILLISECOND, 0);      }else{         calendar.add(Calendar.WEEK_OF_MONTH, -1);         calendar.set(Calendar.DAY_OF_WEEK, weekDay+1);         calendar.set(calendar.get(Calendar.YEAR), calendar.get(Calendar.MONTH),               calendar.get(Calendar.DATE), 0, 0, 0);         calendar.set(Calendar.MILLISECOND, 0);      }   } catch (Exception e) {      // TODO Auto-generated catch block      e.printStackTrace();   }   return calendar;}public static int dayForWeek(String pTime) throws Exception {   SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");   Calendar c = Calendar.getInstance();   c.setTime(format.parse(pTime));   int dayForWeek = 0;   if(c.get(Calendar.DAY_OF_WEEK) == 1){      dayForWeek = 7;   }else{      dayForWeek = c.get(Calendar.DAY_OF_WEEK) - 1;   }   return dayForWeek;
}
public static void main(String[] args) {
SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");System.out.println(String.format("%1$tY-%1$tm-%1$td 00:00:00", getCurrentDay(format.format(new Date()), 5).getTime()));

}