Get time difference Within 2 gregorian Calendars, 1 obtained via SimpleDate

Question

Hi guys
I'm having a problem with an application, i've posted something before about it and with two GregorianCalendars.
This one is receiving a GregorianCalendar value from the default constructor, and the second gregorian calendar from a String, using SimpleDateFormat class
The problem is that whenever i start the application it get stucked at: "Deze datum ligt: 56 in het verleden" meaning from dutch "this datum is 56 days in the past"
the issue is thus at the method "getVerschil()" which means "get difference" in Dutch.
Even if you try to modify the date fields from the class with the main method, inserting new dates it keeps on telling me 56.
I was wondering if you see anything strange in the code and then a little question.
Does the JDK sees a GregorianCalendar made with the default constructor, and a GregorianCalendar made with a SimpleDateFormat string patter "dd-mm-yyyy", in the same way?
I mean, can java make a comparison within the 2 Calendars recognising which are days and which are the months?
Thank you guys:
Below the codes, the first one is the interface and below you'll see the main method class which inserts the date with SimpleDateFormat
public class Kalender {
      * attributes
     private final String patroon;
     private String datum= null;
     private String userDagText= null;
     private int userDag;
     private int userMaand;
     private int userJaar;
     long DAGMILLIS=  24*60*60*1000;
     //deze kalender wordt gemaakt op het moment dat de toepassingen aangezet wordt
     GregorianCalendar nu= new GregorianCalendar();
     //deze kalender word gemaakt door de user-ingevoerde datum
     GregorianCalendar userCalendar= new GregorianCalendar(userDag, userMaand, userJaar);
     //datum formatter
     SimpleDateFormat sdf;
      * Constructor
     public Kalender(String datum, String patroon){
          this.patroon= patroon;
          this.datum=datum;
          sdf= new SimpleDateFormat(patroon);
     }//EOF
     public void setUserDate(){
          Date userDatum= sdf.parse(datum, new ParsePosition(0));
          userCalendar.setTime(userDatum);
          userDag= userCalendar.get(Calendar.DAY_OF_WEEK);
          userMaand= userCalendar.get(Calendar.MONTH);
          userJaar= userCalendar.get(Calendar.YEAR);
     }//EOF
      * deze methode returns de hele date
     public String geefDatum(){
          return sdf.format(userCalendar.getTime());
     }//EOF
      * deze methode bepaald of de ingevoerde datum een schrikkeljaar is
      * deze methode vindt het tijdverschil tussen twee datums
     public String getVerschil(){
          long userMillis= userCalendar.getTimeInMillis();
          long nuMillis= nu.getTimeInMillis();
          if(nuMillis==userMillis){
               return "deze datum zijn gelijk";
          } else if(nuMillis>userMillis){//userdatum in het verleden
               long millisVerschil= nuMillis-userMillis;
               long dagenVerschil= millisVerschil / (DAGMILLIS);
               return "Deze datum ligt: "+dagenVerschil+" in het verleden";
          } else  if(nuMillis<userMillis){//userdatum in het toekomst
               long millisVerschil= userMillis- nuMillis;
               long dagenVerschil= millisVerschil / (DAGMILLIS);
               return "Deze datum ligt: "+dagenVerschil+" in het toekomst";
          return " ";
}The tester (main) class which creates the second GregorianCalendar is the following
public class KalenderTest {
     public static void main(String[] args){
          //constructor werkt
          Kalender kal= new Kalender("01-28-2010", "dd-mm-yyyy");
          //setUserDate werkt
          kal.setUserDate();
          //testen van getVerschil
          System.out.println(""+kal.getVerschil());
     }Edited by: classboy on Apr 26, 2010 9:22 PM
Edited by: classboy on Apr 26, 2010 9:23 PM

Answer 1

classboy wrote:
Does the JDK sees a GregorianCalendar made with the default constructor, and a GregorianCalendar made with a SimpleDateFormat string patter "dd-mm-yyyy", in the same way?Of course not.
And is there anything wrong with your code? Plenty. You passed the fields to the GregorianCalendar constructor in the wrong order. You got the day of the week and then used it as if it were the day of the month. That's just from a quick look, there's probably more.