日期加减

 Calendar calendar = new GregorianCalendar();
 
       SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
  Date   utilDate = new Date();
   utilDate   =   sdf.parse(endYear);输入参数
       calendar.setTime(utilDate);
     calendar.add(Calendar.DATE, 1);负数为减，
     endYear = sdf.format(calendar.getTime());
        System.out.println(endYear);