Why is my JTable row sort is not working?

Question

Hey all,
I wrote the following code for a JTable and I'm trying to use a table sorter to sort the first column content alphabetically, for now. Later, I'd like to use the third column and sort the table's rows based on ascending dates.
For some reason, my comparator is not being called at all and I'm not sure what I'm doing wrong. I'm using JDK 6, which allows me to use a TableRowSorter. It is the first time I'm using this, so I may not know how to use it correctly. Does anybody have any idea what I'm doing wrong?
Please advice.
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.util.Comparator;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTable;
import javax.swing.table.DefaultTableModel;
import javax.swing.table.TableRowSorter;
public class MyTable {
     JTable table;
     public MyTable() {
          JFrame frame = new JFrame("My Table");
          JPanel panel = new JPanel(new BorderLayout());
          table = createTable();
          panel.add(table.getTableHeader(), BorderLayout.NORTH);
          panel.add(table);
          frame.getContentPane().add(panel);
          frame.setSize(new Dimension(400,150));
          frame.setVisible(true);
     private JTable createTable()
          Object [][] data = {{"Nazli", "Shahi", "Wed, Mar 31, 1982"},{"Nima", "Sohrabi", "Thu, Jul 15, 1982"},
                                {"Farsheed", "Tari", "Mon, Jun 13, 1967"}, {"Anousheh", "Modaressi", "Tue, Sep 18, 1964"}};
          String [] columnNames = {"First Name","Last Name","DOB"};
          DefaultTableModel model = new DefaultTableModel(data, columnNames);
          table = new JTable(model);
          TableRowSorter sorter = new TableRowSorter(model);
        sorter.setComparator(0, new MyComparator());
         table.setRowSorter(sorter);
          return table;
     private class MyComparator implements Comparator {
          public int compare(Object s1, Object s2) {
               String first = s1.toString();
               String second = s2.toString();               
               System.err.println("returning "+(first.substring(0, 1)).compareTo(second.substring(0, 1)));
               return (first.substring(0, 1)).compareTo(second.substring(0, 1));
     public static void main(String[] args) {
          MyTable test = new MyTable();
}

Answer 1

Alrite, so now I have Date objects in the model instead of String objects. Now, my question is, how can I actually sort the Date column with the latest dates showing on top and earlier dates showing on the bottom?
The table provides a default Comparator to sort dates. You just need to tell the table what type of data is stored in each column. This is done by overriding the getColumnClass() method of JTable or TableModel.
Camickr, you once said that the table provides a default Comparator to sort dates. and I just need to tell the table what type of data is stored in each column. This is done by overriding the getColumnClass() method of JTable or TableModel.
With the current code that I have in getColumnClass I am not able to compare anything yet. Is there anything else I need to do? I'm a bit clueless, so I'd appreciate your help.
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.util.Date;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTable;
import javax.swing.table.DefaultTableModel;
public class MyTable {
    JTable table;
    DefaultTableModel model;
    public MyTable() {
        JFrame frame = new JFrame("My Table");
        JPanel panel = new JPanel(new BorderLayout());
        table = createTable();
        panel.add(table.getTableHeader(), BorderLayout.NORTH);
        panel.add(table);
        frame.getContentPane().add(panel);
        frame.setSize(new Dimension(400,150));
        frame.setVisible(true);
    private JTable createTable() {
        Object [][] data = {{"Nazli", "Sh", new Date(192837429L)},{"Nima", "So", new Date(1293847L)},
                            {"Farsheed", "T", new Date(9872347892L)}, {"Anousheh", "M", new Date(234321234L)}};
        String [] columnNames = {"First Name","Last Name","DOB"};
        model = new MyTableModel(data, columnNames);
        table = new JTable(model);
        return table;
    public static void main(String[] args) {
        MyTable test = new MyTable();
    private class MyTableModel extends DefaultTableModel {
         public MyTableModel(Object [][] data, String [] columnNames) {
              super(data, columnNames);
         public Class getColumnClass(int column) {
              System.err.println(column);
              if(column==2)
                   return getValueAt(column, 2).getClass();
              else
                   return Object.class;
}