Date editing in a JTable

Question

Hello,
whereas a JFormattedTextField with a mask formatter can be used as editor in a
JTable just like in a container, a JFormattedTextField with a date formatter
obviously cannot. The tutorial warns us that table cells are NOT components,
but in what cases do we have to care?
I also understand the tutorial in the way that while editing, the editor is
responsible for displaying the cell, and the cell renderer takes over again
when editing is stopped. Is that right? If yes, I would not have to care for
a special renderer, for I'm quite happy with the default one.
I'm trying to use a JFormattedTextField which would, if working, need only
little code, for the solutions I found in the net are quite expanded.
The code below is in many ways defective:
1) Without renderer
When editing of the date column starts, the date is displayed in the
"dow mon dd hh:mm:ss zzz yyyy" form, and doesn't revert even when no edits
are performed. This doesn't happen if the JFormattedTextField is used
outside a table.
2) With renderer
The value arrives in the renderer sometimes as Object, sometimes as String
(I suppose the editor is responsible for that.)
But before I pursue this approach I would like to ask you, whether you
generally discourge using a JFormattedTextField in a date column.
If not, please comment my understanding and direct me to a solution.
import java.awt.*;
import java.text.*; // ParseException
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.text.*; // MaskFormatter
import javax.swing.table.*;
public class FTFTable extends JFrame {
  public FTFTable() {
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setSize(200, 200);
    setTitle("FTFTable");
    Container cp = getContentPane();
    String headers[] = {"Date", "Mask: #-##"};
    DateFormat format= new SimpleDateFormat("dd.MM.yyyy");
    DateFormatter df= new DateFormatter(format);
    JFormattedTextField ftfDate= new JFormattedTextField(df);
    MaskFormatter mf1= null;
    try {
      mf1= new MaskFormatter("#-##");
      mf1.setPlaceholderCharacter('_');
    catch (ParseException e) {
      System.out.println(e);
    JFormattedTextField ftf= new JFormattedTextField(mf1);
    final DefaultTableModel dtm= createTableModel(headers);
    dtm.addRow(new Object[]{new java.util.Date(), "1-23"});
    JTable table= new JTable(dtm);
    DefaultTableColumnModel dcm=(DefaultTableColumnModel)table.getColumnModel
//  Use custom editors
    dcm.getColumn(0).setCellEditor(new DefaultCellEditor(ftfDate));
//    dcm.getColumn(0).setCellRenderer(new MyDateRenderer());
    dcm.getColumn(1).setCellEditor(new DefaultCellEditor(ftf));
    JScrollPane scrollPane = new JScrollPane(table);
    cp.add(scrollPane, BorderLayout.CENTER);
    setVisible(true);
  public static void main(String args[]) {
    java.awt.EventQueue.invokeLater(new Runnable() {
      public void run() {
     new FTFTable();
  private DefaultTableModel createTableModel(Object[] columnNames) {
    DefaultTableModel tblModel= new DefaultTableModel(columnNames, 0) {
      public Class getColumnClass(int column) {
     Class returnValue;
     if (column>=0 && column<getColumnCount()) {
       returnValue= getValueAt(0, column).getClass();
     else {
       returnValue= Object.class;
     return returnValue;
    return tblModel;
  class MyDateRenderer extends DefaultTableCellRenderer {
    DateFormat format;
    public MyDateRenderer() {
      super();
      format= new SimpleDateFormat("dd.MM.yyyy");
    public void setValue(Object value) {
      if (value instanceof String) System.out.println("Is String");
      if (value instanceof Object) System.out.println("Is Object");
      System.out.println(value);
      System.out.println(format.format(value)); // Crashes if String
      setText((value == null) ? "" : format.format(value));
}

Answer 1

Thanks Rob, that was helpful advice.
If one needs the date displayed only in the form of one's own locale, there's
no need to implement a cell renderer. Using a JFormattedTextField provides the
additional facility of using the arrow keys to modify days, months or year.
import java.awt.*;
import java.text.*; // ParseException
import java.util.*;
import javax.swing.*;
import javax.swing.border.*;
import javax.swing.event.*;
import javax.swing.text.*; // MaskFormatter
import javax.swing.table.*;
public class FTFTable extends JFrame {
  public FTFTable() {
    setDefaultCloseOperation(EXIT_ON_CLOSE);
    setSize(200, 200);
    setTitle("FTFTable");
    Container cp = getContentPane();
    String headers[] = {"Date", "Mask: #-##"};
    MaskFormatter mf1= null;
    try {
      mf1= new MaskFormatter("#-##");
      mf1.setPlaceholderCharacter('_');
    catch (ParseException e) {
      System.out.println(e);
    JFormattedTextField ftf= new JFormattedTextField(mf1);
    DefaultTableModel dtm= createTableModel(headers);
    dtm.addRow(new Object[]{new Date(), "1-23"});
    JTable table= new JTable(dtm);
//    Locale.setDefault(Locale.FRANCE);
//  Use custom editors
    table.setDefaultEditor(Date.class, new DateEditorSupply().getEditor());
    DefaultTableColumnModel dcm=(DefaultTableColumnModel)table.getColumnModel();
    dcm.getColumn(1).setCellEditor(new DefaultCellEditor(ftf));
    JScrollPane scrollPane = new JScrollPane(table);
    cp.add(scrollPane, BorderLayout.CENTER);
    setVisible(true);
  public static void main(String args[]) {
    java.awt.EventQueue.invokeLater(new Runnable() {
      public void run() {
     new FTFTable();
  private DefaultTableModel createTableModel(Object[] columnNames) {
    DefaultTableModel tblModel= new DefaultTableModel(columnNames, 0) {
      public Class getColumnClass(int column) {
     Class returnValue;
     if (column>=0 && column<getColumnCount()) {
       returnValue= getValueAt(0, column).getClass();
     else {
       returnValue= Object.class;
     return returnValue;
    return tblModel;
  public class DateEditorSupply {
    DateEditor editor;
    SimpleDateFormat format;
    public DateEditorSupply() {
//     To be modified according to the locale's default.
//      this("dd MMM yyyy"); // FRANCE
//      this("dd.MM.yyyy"); // GERMANY
      this("dd-MMM-yyyy"); // UK
//      this("MMM d, yyyy"); // US
//Currently this constructor can only be used with the locale's default pattern.
// If you need various patterns, you have to implement a cell renderer as well.
    public DateEditorSupply(String pattern) {
      format= new SimpleDateFormat(pattern);
      format.setLenient(false);
      editor= new DateEditor();
    public DefaultCellEditor getEditor() {
      return editor;
    private class DateEditor extends DefaultCellEditor {
      public DateEditor() {
     super(new JFormattedTextField(new DateFormatter(format)));
      @Override
      public Object getCellEditorValue() {
     try {
       java.sql.Date value= new java.sql.Date(format.parse(
               ((JTextField)getComponent()).getText()).getTime());
       return value;
     catch (ParseException ex) {
       return null;
      @Override
      public Component getTableCellEditorComponent(
          final JTable table, final Object value,
          final boolean isSelected, final int row, final int column) {
     JTextField tf= ((JTextField)getComponent());
     tf.setBorder(new LineBorder(Color.black));
     try {
       tf.setText(format.format(value));
     catch (Exception e) {
       tf.setText("");
     return tf;
      public boolean parseDate(String value) {
     ParsePosition pos= new ParsePosition(0);
     format.parse(value, pos); // updates pos.
     if (pos.getIndex()!=value.length() ||
         format.getCalendar().get(Calendar.YEAR)>2500) return false;
     return true;
      @Override
      public boolean stopCellEditing() {
     String value = ((JTextField)getComponent()).getText();
     if (!value.equals("")) {
/*       This code would accept alphabetic characters within or at the end of
//       the year in a dd.MM.yyyy pattern, as well as more than 4-digits in the
//       year string.
       try {
         format.parse(value);
       catch (ParseException e) {
         ((JComponent)getComponent()).setBorder(new LineBorder(Color.red));
         return false;
       We avoid this in using "parseDate(value)" instead.
       if (!parseDate(value)) {
         ((JComponent)getComponent()).setBorder(new LineBorder(Color.red));
         return false;
     return super.stopCellEditing();
    } // end DateEditor
}Thanks to André for sharing his .
Edited by: Joerg22 on 03.07.2010 14:11
I made some changes to the DateEditorSupply class, so that the code can easily be used when storing the table date in a database.