Cannot display JLabel text in JTable

Question

Hi, This is a simple but frustrating little problem
I am having trouble displaying the label text in a column of a JTable.
I have hacked up a copy of TableDialogEditDemo.java from the tutorials
on using JTables. This uses a renderer and editor models to deal with a
column of colors.
I have changed it to use JLabels instead. What want is for the label
text to appear and when the user selects the cell be allowed to launch
a dialog box (such as the demo program does with colorchooser).
The dialog launching funcionalty works fine but the label text does not display.
I end up with the column of JLabels as blank, even though the values
are properly set. It seems like the TableCellRenderer doesn't display the
controls text.
I've spent the better part of two work days trying to get this one to work.
Compiling and just running the code (without any interaction with the table)
shows the problem. The second column of items will be blank instead of
cells with text.
Help!
Thanks!
/Steve McCauley
Sanera Systems
[email protected]
Here is the code:
import javax.swing.JTable;
import javax.swing.table.AbstractTableModel;
import javax.swing.DefaultCellEditor;
import javax.swing.table.TableCellRenderer;
import javax.swing.JLabel;
import javax.swing.JDialog;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JColorChooser;
import javax.swing.BorderFactory;
import javax.swing.border.Border;
import javax.swing.JScrollPane;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;
import java.awt.*;
import java.awt.event.*;
* This is like TableEditDemo, except that it substitutes a
* Favorite Color column for the Last Name column and specifies
* a custom cell renderer and editor for the color data.
public class TableDialogEditDemo extends JFrame {
private boolean DEBUG = false;
public TableDialogEditDemo() {
super("TableDialogEditDemo");
MyTableModel myModel = new MyTableModel();
JTable table = new JTable(myModel);
table.setPreferredScrollableViewportSize(new Dimension(500, 70));
//Create the scroll pane and add the table to it.
JScrollPane scrollPane = new JScrollPane(table);
//Set up renderer and editor for the Favorite Color column.
setUpColorRenderer(table);
setUpColorEditor(table);
//Set up real input validation for integer data.
setUpIntegerEditor(table);
//Add the scroll pane to this window.
getContentPane().add(scrollPane, BorderLayout.CENTER);
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
class ColorRenderer extends JLabel
implements TableCellRenderer {
Border unselectedBorder = null;
Border selectedBorder = null;
boolean isBordered = true;
public ColorRenderer(boolean isBordered) {
super();
this.isBordered = isBordered;
// setOpaque(true); //MUST do this for background to show up.
public Component getTableCellRendererComponent(
JTable table, Object color,
boolean isSelected, boolean hasFocus,
int row, int column) {
// setBackground((Color)color);
setForeground(Color.black);
setBackground(Color.white);
System.out.println(" Label: " + ((JLabel)color).getText());
if (isBordered) {
if (isSelected) {
if (selectedBorder == null) {
selectedBorder = BorderFactory.createMatteBorder(2,5,2,5,
table.getSelectionBackground());
setBorder(selectedBorder);
} else {
if (unselectedBorder == null) {
unselectedBorder = BorderFactory.createMatteBorder(2,5,2,5,
table.getBackground());
setBorder(unselectedBorder);
return this;
private void setUpColorRenderer(JTable table) {
table.setDefaultRenderer(JLabel.class,
new ColorRenderer(true));
//Set up the editor for the Color cells.
private void setUpColorEditor(JTable table) {
//First, set up the button that brings up the dialog.
final JButton button = new JButton("") {
public void setText(String s) {
//Button never shows text -- only color.
button.setBackground(Color.white);
button.setBorderPainted(false);
button.setMargin(new Insets(0,0,0,0));
//Now create an editor to encapsulate the button, and
//set it up as the editor for all Color cells.
final ColorEditor colorEditor = new ColorEditor(button);
table.setDefaultEditor(JLabel.class, colorEditor);
//Set up the dialog that the button brings up.
final JColorChooser colorChooser = new JColorChooser();
ActionListener okListener = new ActionListener() {
public void actionPerformed(ActionEvent e) {
colorEditor.currentLabel = new JLabel("xxx");
final JDialog dialog = JColorChooser.createDialog(button,
"Pick a Color",
true,
colorChooser,
okListener,
null); //XXXDoublecheck this is OK
//Here's the code that brings up the dialog.
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
// button.setBackground(colorEditor.currentColor);
// colorChooser.setColor(colorEditor.currentColor);
//Without the following line, the dialog comes up
//in the middle of the screen.
//dialog.setLocationRelativeTo(button);
dialog.show();
* The editor button that brings up the dialog.
* We extend DefaultCellEditor for convenience,
* even though it mean we have to create a dummy
* check box. Another approach would be to copy
* the implementation of TableCellEditor methods
* from the source code for DefaultCellEditor.
class ColorEditor extends DefaultCellEditor {
JLabel currentLabel = null;
public ColorEditor(JButton b) {
super(new JCheckBox()); //Unfortunately, the constructor
//expects a check box, combo box,
//or text field.
editorComponent = b;
setClickCountToStart(1); //This is usually 1 or 2.
//Must do this so that editing stops when appropriate.
b.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
fireEditingStopped();
protected void fireEditingStopped() {
super.fireEditingStopped();
public Object getCellEditorValue() {
return currentLabel;
public Component getTableCellEditorComponent(JTable table,
Object value,
boolean isSelected,
int row,
int column) {
((JButton)editorComponent).setText(value.toString());
currentLabel = (JLabel)value;
return editorComponent;
private void setUpIntegerEditor(JTable table) {
//Set up the editor for the integer cells.
final WholeNumberField integerField = new WholeNumberField(0, 5);
integerField.setHorizontalAlignment(WholeNumberField.RIGHT);
DefaultCellEditor integerEditor =
new DefaultCellEditor(integerField) {
//Override DefaultCellEditor's getCellEditorValue method
//to return an Integer, not a String:
public Object getCellEditorValue() {
return new Integer(integerField.getValue());
table.setDefaultEditor(Integer.class, integerEditor);
class MyTableModel extends AbstractTableModel {
final String[] columnNames = {"First Name",
"Favorite Color",
"Sport",
"# of Years",
"Vegetarian"};
// final Object[][] data = {
// {"Mary", new Color(153, 0, 153),
// "Snowboarding", new Integer(5), new Boolean(false)},
// {"Alison", new Color(51, 51, 153),
// "Rowing", new Integer(3), new Boolean(true)},
// {"Kathy", new Color(51, 102, 51),
// "Chasing toddlers", new Integer(2), new Boolean(false)},
// {"Mark", Color.blue,
// "Speed reading", new Integer(20), new Boolean(true)},
// {"Philip", Color.pink,
// "Pool", new Integer(7), new Boolean(false)}
final Object[][] data = {
{"Mary", new JLabel("label-1"),
"Snowboarding", new Integer(5), new Boolean(false)},
{"Alison", new JLabel("label-2"),
"Rowing", new Integer(3), new Boolean(true)},
{"Kathy", new JLabel("label-3"),
"Chasing toddlers", new Integer(2), new Boolean(false)},
{"Mark", new JLabel("label-4"),
"Speed reading", new Integer(20), new Boolean(true)},
{"Philip", new JLabel("label-5"),
"Pool", new Integer(7), new Boolean(false)}
public int getColumnCount() {
return columnNames.length;
public int getRowCount() {
return data.length;
public String getColumnName(int col) {
return columnNames[col];
public Object getValueAt(int row, int col) {
return data[row][col];
* JTable uses this method to determine the default renderer/
* editor for each cell. If we didn't implement this method,
* then the last column would contain text ("true"/"false"),
* rather than a check box.
public Class getColumnClass(int c) {
return getValueAt(0, c).getClass();
* Don't need to implement this method unless your table's
* editable.
public boolean isCellEditable(int row, int col) {
//Note that the data/cell address is constant,
//no matter where the cell appears onscreen.
if (col < 1) {
return false;
} else {
return true;
public void setValueAt(Object value, int row, int col) {
if (DEBUG) {
System.out.println("Setting value at " + row + "," + col
+ " to " + value
+ " (an instance of "
+ value.getClass() + ")");
data[row][col] = value;
fireTableCellUpdated(row, col);
if (DEBUG) {
System.out.println("New value of data:");
printDebugData();
private void printDebugData() {
int numRows = getRowCount();
int numCols = getColumnCount();
for (int i=0; i < numRows; i++) {
System.out.print(" row " + i + ":");
for (int j=0; j < numCols; j++) {
System.out.print(" " + data[i][j]);
System.out.println();
System.out.println("--------------------------");
public static void main(String[] args) {
TableDialogEditDemo frame = new TableDialogEditDemo();
frame.pack();
frame.setVisible(true);

Answer 1

You pretty much hit the nail on the head. Thank!
Just didn't realize I needed to set the text of the component but with your
tip and thinking about it, it makes sense.
Actually I needed to use:
setText(t_label.getText());
Using toString got me: "java.swing......" (the components text representation)
Thanks a bunch!
/Steve