Java获取某年某月的第一天和最后一天

/**
           * 获取某年某月的第一天
           * @Title:getFisrtDayOfMonth
           * @Description:
           * @param:@param year
           * @param:@param month
           * @param:@return
           * @return:String
           * @throws
           */
          public static String getFisrtDayOfMonth(int year,int month){
            Calendar cal = Calendar.getInstance();
            //设置年份
            cal.set(Calendar.YEAR,year);
            //设置月份
            cal.set(Calendar.MONTH, month-1);
            //获取某月最小天数
            int firstDay = cal.getActualMinimum(Calendar.DAY_OF_MONTH);
            //设置日历中月份的最小天数
            cal.set(Calendar.DAY_OF_MONTH, firstDay);
            //格式化日期
            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
            String firstDayOfMonth = sdf.format(cal.getTime());
            return firstDayOfMonth;
          }
          /**
           * 获取某月的最后一天
           * @Title:getLastDayOfMonth
           * @Description:
           * @param:@param year
           * @param:@param month
           * @param:@return
           * @return:String
           * @throws
           */
          public static String getLastDayOfMonth(int year,int month)
          {
            Calendar cal = Calendar.getInstance();
            //设置年份
            cal.set(Calendar.YEAR,year);
            //设置月份
            cal.set(Calendar.MONTH, month-1);
            //获取某月最大天数
            int lastDay = cal.getActualMaximum(Calendar.DAY_OF_MONTH);
            //设置日历中月份的最大天数
            cal.set(Calendar.DAY_OF_MONTH, lastDay);
            //格式化日期
            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
            String lastDayOfMonth = sdf.format(cal.getTime());
            return lastDayOfMonth;
          }