Calculer l'écart entre 2 dates

Ce code calcul l'écart en années / mois / jours  (complets) entre 2 dates :

Ajouter les imports suivants :

import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.text.ParseException;
import java.text.SimpleDateFormat;

public class ecartDate {

    static int UN = 1;
    static int DOUZE = 12;

    public static void main(String[] args) {
  
        Calendar calStr1 = Calendar.getInstance();
        Calendar calStr2 = Calendar.getInstance();
        Calendar calStr0 = Calendar.getInstance();
  
        Date date1 = null;
        Date date2 = null;
   
        int nbMois = 0;
        int nbAnnees = 0;
        long nbJours = 0;
   
        try {
                date1 = new SimpleDateFormat("dd/MM/yyyy").parse("25/01/2006");
        } catch (ParseException e) {
                e.printStackTrace();
        }
        try {
                date2 = new SimpleDateFormat("dd/MM/yyyy").parse("11/02/2014");
        } catch (ParseException e) {
                e.printStackTrace();
        }

        if (date1.equals(date2)) {
                return;
        }

        calStr1.setTime(date1);
        calStr2.setTime(date2);

        nbMois = 0;
        while (calStr1.before(calStr2)) {
                calStr1.add(GregorianCalendar.MONTH, UN);
                if (calStr1.before(calStr2) || calStr1.equals(calStr2)) {
                        nbMois++;
                }
        }
        nbAnnees = (nbMois / DOUZE);
        nbMois = (nbMois - (nbAnnees * DOUZE));

        calStr0 = Calendar.getInstance();
        calStr0.setTime(date1);
        calStr0.add(GregorianCalendar.YEAR, nbAnnees);
        calStr0.add(GregorianCalendar.MONTH, nbMois);
        nbJours = (calStr2.getTimeInMillis() - calStr0.getTimeInMillis()) / 86400000;

        System.out.print("Nb Annees : "+nbAnnees+"\n");
        System.out.print("Nb Mois : "+nbMois+"\n");
        System.out.print("Nb Jours : "+nbJours+"\n");

        }
}