获取当月第一天和最后一天

获取每月第一天方法

public static String getFirstDay() {
      SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
      // 获取当年每月的第一天
      Calendar begin = Calendar.getInstance();
      begin.set(Calendar.DAY_OF_MONTH,   
                begin.getActualMinimum(Calendar.DAY_OF_MONTH));
      begin.set(Calendar.SECOND, 0);
      begin.set(Calendar.HOUR_OF_DAY, 0);
      begin.set(Calendar.MINUTE, 0);
      String start = sdf.format(begin.getTime());
      return start;
  }

获取每月最后一天方法

public static String getLastDay() {
      SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
      // 获取当前月最后一天
      Calendar end = Calendar.getInstance();
      end.set(Calendar.DAY_OF_MONTH,ca.getActualMaximum(
              Calendar.DAY_OF_MONTH));
      String end = sdf.format(ca.getTime());
      return end;
}