Sorting a date represented in three integers.

Question

Hey,
I have an other question. I want to sort a collection on the data. In my collection I have three integers representing the date (int matchDay, int matchMonth, int matchYear)
The constructor for the Collection<Comment> is:
public Comment(int matchID, int matchDay, int matchMonth, int matchYear, String namePlayer, String comments) I want the comments which happened at the beginning at the bottom and the comments which just happened at the top. So, I want to sort in a decending order.
I tried to sort with severly options. The most likely which I thought was to succed, is this code:
// To sort Comments selection
public Collection<Comment> sortCommentCollection(Collection<Comment> comments) {
    Collection<Comment> backup = new ArrayList<Comment>();
    String DATE_FORMAT = "yyyy-MM-dd";
    java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat(DATE_FORMAT);
    Calendar c1 = Calendar.getInstance();
    Calendar c2 = Calendar.getInstance();
    int year = 1000, month = 00, day = 00, x = 0;
    boolean attached = false;
    for(Comment c : comments) {
        // remember months are zero-based : 0 jan 1 feb ...
        c1.set(year, month, day);
        c2.set(c.getMatchYear(), c.getMatchMonth() , c.getMatchDay());
        if (c1.before(c2) && !attached) {
            // Remove 'older' comment before adding this comment
            backup.remove(x - 1);
            Comment temporary = new Comment(c.getMatchID(), c.getMatchDay(), c.c.getMatchMonth(), c .c.getMatchYear(), c.getNamePlayer(), c.getComments());
            backup.add(temporary);
            attached = true;
        if (c1.after(c2) && !atteched) {
            Comment temporary = new Comment(c.getMatchID(), c.getMatchDay(), c.c.getMatchMonth(), c .c.getMatchYear(), c.getNamePlayer(), c.getComments());
            backup.add(temporary);
            attached = true;
        if (c1.equals(c2)) {
            // To prevent double entries
            backup.remove(x - 1);
        year = c.getMatchYear();
        month = c.getMatchMonth();
        day = c.getMatchDay();
        attached = false;
        x++;
        return backup;
}But this did not work either. Does anyboedy have a suggestion? You would help me a lot! Thanks in advance.

Answer 1

Vinvar wrote:
I want to sort a collection on the data. In my collection I have three integers representing the date (int matchDay, int matchMonth, int matchYear)Just add another integer representing roughly the days since Jesus' birth, then you can simply sort by that.
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.Random;
public class Comment
     private final int _year;
     private final int _month;
     private final int _day;
     private final int _jesus;
     private final String _string;
     public Comment(int year, int month, int day)
          _year = year;
          _month = month;
          _day = day;
          // calculate approx. days since Jesus' birth
          _jesus = (_year * 12 + _month) * 31 + _day;
          _string = String.format("%02d-%02d-%04d", _month, _day, _year);
     public int getMatchYear()
          return _year;
     public int getMatchMonth()
          return _month;
     public int getMatchDay()
          return _day;
     public int getJesus()
          return _jesus;
     @Override
     public String toString()
          return _string;
class DescendingComments implements Comparator<Comment>
     @Override
     public int compare(Comment o1, Comment o2)
          return o2.getJesus() - o1.getJesus();
class TestComment
     public static void main(String[] args)
          List<Comment> comments = new ArrayList<Comment>();
          Random rand = new Random();
          for (int i = 0; i < 10; ++i)
               comments.add(new Comment(
                         rand.nextInt(2000),
                         rand.nextInt(12) + 1,
                         rand.nextInt(31) + 1));
          System.out.println(comments);
          Collections.sort(comments, new DescendingComments());
          System.out.println(comments);
}