Java 求n天前的时间或者n月前的时间

时间格式化

public static String DEFAULT_FORMATDATE = "yyyy-MM-dd";

1.n天前的日期

/**
 * luyanlong
 * 默认查询前几天的数据
 */
public void formatTimeDay(int duringTime){
   Calendar calendar=Calendar.getInstance();
   String start=StringUtils.EMPTY;
   String end=StringUtils.EMPTY;
   try {
      end=CCalendar.dateFormatString(DEFAULT_FORMATDATE,  calendar.getTime());
      calendar.set(Calendar.DAY_OF_YEAR, calendar.get(Calendar.DAY_OF_YEAR) - duringTime);
      start = CCalendar.dateFormatString(DEFAULT_FORMATDATE,  calendar.getTime());
   } catch (ParseException e) {
      e.printStackTrace();
   }
   this.setAttr("startTime",start);
   this.setAttr("endTime",end);
}

2.n月前的时间

/**
 * luyanlong
 * 默认查询前几月的数据
 */
public void formatTimeMonth(int duringMonth){
   Calendar calendar=Calendar.getInstance();
   String start=StringUtils.EMPTY;
   String end=StringUtils.EMPTY;
   try {
      end=CCalendar.dateFormatString(DEFAULT_FORMATDATE,  calendar.getTime());

      calendar.set(Calendar.MONTH, calendar.get(Calendar.MONTH) - duringMonth);
      start = CCalendar.dateFormatString(DEFAULT_FORMATDATE,  calendar.getTime());
   } catch (ParseException e) {
      e.printStackTrace();
   }
   this.setAttr("startTime",start);
   this.setAttr("endTime",end);
}