时间加减月数/年数

/**
 * 时间加减月数
 * @param startDate 要处理的时间，Null则为当前时间
 * @param months 加减的月数
 * @return Date
 */
public static Date dateAddMonths(Date startDate, int months) {
   if (startDate == null) {
      startDate = new Date();
   }
   Calendar c = Calendar.getInstance();
   c.setTime(startDate);
   c.set(Calendar.MONTH, c.get(Calendar.MONTH) + months);
   return c.getTime();
}

/**
 * 时间加减年数
 * @param startDate 要处理的时间，Null则为当前时间
 * @param years 加减的年数
 * @return Date
 */
public static Date dateAddYears(Date startDate, int years) {
   if (startDate == null) {
      startDate = new Date();
   }
   Calendar c = Calendar.getInstance();
   c.setTime(startDate);
   c.set(Calendar.YEAR, c.get(Calendar.YEAR) + years);
   return c.getTime();
}