java Calendar

public static Calendar par(String dateStr,String frmat){
SimpleDateFormat sdf = new SimpleDateFormat(frmat);
Calendar cal = Calendar.getInstance();
try {
Date date = sdf.parse(dateStr);
cal.setTimeInMillis(date.getTime());
} catch (Exception e) {
return null;
}
return cal;
}
      Calendar now_calendar =  Calendar.getInstance();
      System.out.println(now_calendar.getTime());
     
      String y= "2011-10-21 13:10:00";
      Calendar calendar = Calendar.getInstance();
      calendar = par(y,"yyyy-MM-dd HH:mm:ss");
      System.out.println(calendar.getTime());
     
      Calendar calendar_before = Calendar.getInstance();
      calendar_before = par(y,"yyyy-MM-dd HH:mm:ss");
      calendar_before.add(calendar_before.MINUTE, -5);
      System.out.println(calendar_before.getTime());
      System.out.println(now_calendar.compareTo(calendar_before));
     
      Calendar calendar_after = Calendar.getInstance();
      calendar_after = par(y,"yyyy-MM-dd HH:mm:ss");
      calendar_after.add(calendar_after.MINUTE, 5);
      System.out.println(calendar_after.getTime());
      System.out.println(now_calendar.compareTo(calendar_after));
     
      if((now_calendar.compareTo(calendar_before)) >=0 && (now_calendar.compareTo(calendar_after)) <= 0){
      System.out.println("OK");
      }else{
      System.out.println("NO");
      }