Problem in adding JComboBox in JTable

Question

Hi,
I was trying to put some comboxes in a jtable. The problem is I am not able to add combo boxes in the 1st and 2nd column. But its adding from the 3rd column. What can be wrong in the following code?
import javax.swing.DefaultCellEditor;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.AbstractTableModel;
import javax.swing.table.DefaultTableCellRenderer;
import javax.swing.table.TableCellRenderer;
import javax.swing.table.TableColumn;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.GridLayout;
import javax.swing.*;
* TableRenderDemo is just like TableDemo, except that it
* explicitly initializes column sizes and it uses a combo box
* as an editor for the Sport column.
public class TableRenderDemo1 extends JPanel {
    private boolean DEBUG = true;
        DefaultTableCellRenderer renderer =  new DefaultTableCellRenderer();
    public TableRenderDemo1() {
        //super(new GridLayout(1,0));
        JTable table = new JTable(new MyTableModel());
        table.setPreferredScrollableViewportSize(new Dimension(500, 250));
        //Create the scroll pane and add the table to it.
        JScrollPane scrollPane = new JScrollPane(table);
        //Set up column sizes.
        initColumnSizes(table);
        //Fiddle with the Sport column's cell editors/renderers.
        setUpNameColumn(table, table.getColumnModel().getColumn(3));
        //Fiddle with the Sport column's cell editors/renderers.
        setUpSportColumn(table, table.getColumnModel().getColumn(4));
        //Add the scroll pane to this panel.
        add(scrollPane);
        String strPlaf = "com.sun.java.swing.plaf.windows.WindowsLookAndFeel";
        try {
                UIManager.setLookAndFeel(strPlaf);
                SwingUtilities.updateComponentTreeUI(scrollPane);
        } catch(Exception e) {
                e.printStackTrace();
     * This method picks good column sizes.
     * If all column heads are wider than the column's cells'
     * contents, then you can just use column.sizeWidthToFit().
    private void initColumnSizes(JTable table) {
        MyTableModel model = (MyTableModel)table.getModel();
        TableColumn column = null;
        Component comp = null;
        int headerWidth = 0;
        int cellWidth = 0;
        Object[] longValues = model.longValues;
        TableCellRenderer headerRenderer = table.getTableHeader().getDefaultRenderer();
        for (int i = 0; i < 5; i++) {
            column = table.getColumnModel().getColumn(i);
            comp = headerRenderer.getTableCellRendererComponent(
                                 null, column.getHeaderValue(),
                                 false, false, 0, 0);
            headerWidth = comp.getPreferredSize().width;
            comp = table.getDefaultRenderer(model.getColumnClass(i)).
                             getTableCellRendererComponent(
                                 table, longValues,
false, false, 0, i);
cellWidth = comp.getPreferredSize().width;
if (DEBUG) {
System.out.println("Initializing width of column "
+ i + ". "
+ "headerWidth = " + headerWidth
+ "; cellWidth = " + cellWidth);
//XXX: Before Swing 1.1 Beta 2, use setMinWidth instead.
column.setPreferredWidth(Math.max(headerWidth, cellWidth));
public void setUpSportColumn(JTable table, TableColumn sportColumn) {
//Set up the editor for the sport cells.
JComboBox comboBox = new JComboBox();
comboBox.addItem("Snowboarding");
comboBox.addItem("Rowing");
comboBox.addItem("Knitting");
comboBox.addItem("Speed reading");
comboBox.addItem("Pool");
comboBox.addItem("None of the above");
comboBox.setVisible(true);
sportColumn.setCellEditor(new DefaultCellEditor(comboBox));
//Set up tool tips for the sport cells.
renderer.setToolTipText("Click for combo box");
sportColumn.setCellRenderer(renderer);
public void setUpNameColumn(JTable table, TableColumn nameColumn) {
//Set up the editor for the sport cells.
JComboBox comboBox = new JComboBox();
comboBox.addItem("One");
comboBox.addItem("Two");
comboBox.addItem("Three");
comboBox.addItem("Four");
comboBox.addItem("Five");
comboBox.setVisible(true);
nameColumn.setCellEditor(new DefaultCellEditor(comboBox));
//Set up tool tips for the sport cells.
renderer.setToolTipText("Click for combo box");
nameColumn.setCellRenderer(renderer);
class MyTableModel extends AbstractTableModel {
private String[] columnNames = {"First Name",
"Last Name",
"Sport",
"# of Years",
"Vegetarian"};
private Object[][] data = {
{"Mary", "Saikat", "Snowboarding", new Integer(5), new Boolean(false)},
{"Alison", "Srinath", "Rowing", new Integer(3), new Boolean(true)},
{"Kathy", "Sheela", "Knitting", new Integer(2), new Boolean(false)},
{"John", "Yashwant", "Something", new Integer(5), new Boolean(true)},
{"Harry", "Jay", "Playing", new Integer(1), new Boolean(true)},
public final Object[] longValues = {"Sharon", "Campione",
"None of the above",
new Integer(20), Boolean.TRUE};
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 < 2) {
return false;
} else {
return true;
* Don't need to implement this method unless your table's
* data can change.
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("--------------------------");
* Create the GUI and show it. For thread safety,
* this method should be invoked from the
* event-dispatching thread.
private static void createAndShowGUI() {
//Create and set up the window.
JFrame frame = new JFrame("TableRenderDemo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//Create and set up the content pane.
TableRenderDemo1 newContentPane = new TableRenderDemo1();
newContentPane.setOpaque(true); //content panes must be opaque
frame.setContentPane(newContentPane);
//Display the window.
frame.pack();
frame.setVisible(true);
public static void main(String[] args) {
//Schedule a job for the event-dispatching thread:
//creating and showing this application's GUI.
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
Thanks in advance.

Answer 1

First, I don't see where you are tying to set the combo box on the first two columns. I only see it for the 3 and 4.
Also why are you putting combo boxes in columns that are not 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 < 2) {
                return false;
            } else {
                return true;
        }