Help with JTable - content of cell disappears when selected

Question

Hello,
I have a jTable and I have created a custom cell renderer. It does what it's supposed to do (which is set the background color of all cells with null or "" value to red - as an indication to the user that b4 proceeding he/she has to fill in this cells). The problem is that when I select a red cell, it becomes white and the text value it contains disappears. When I double click I can start typing in a new value.
I would appreciate any hint why this happens? Ideally I would like the cell to keep its color when clicked or double-clicked and its value, and only when i'm done editing its content and it's not null or empty string to become white.
I'm including majority of my code (some automatically generated code from Netbeans is not included).
Thank you very much,
Laura
public class DataNormalisation extends javax.swing.JFrame {   
    JTextArea txt=new JTextArea();
    public Object[][] DataSummary;
    public Vector<String> colName;
    MainF p;
    String[] ExpNames;
    /** Creates new form DataNormalisation */
    public DataNormalisation(String[] EN, MainF parent) {
        p=parent;
        ExpNames=EN;
        colName= new Vector<String>();
        colName.add("Sample Name");
        colName.add("Replicate Group");
        DataSummary=new Object[ExpNames.length][2];
        for (int i=0;i<ExpNames.length;i++){
            DataSummary[0]=ExpNames[i];
initComponents();
this.jTable1.getTableHeader().setReorderingAllowed(false);
TableColumn column = jTable1.getColumnModel().getColumn(1);
column.setCellRenderer(new CustomTableCellRenderer());
private void initComponents() {
jScrollPane1 = new javax.swing.JScrollPane();
jTable1 = new JTable (new DataModel());
jButton1 = new javax.swing.JButton();
jButton2 = new javax.swing.JButton();
jLabel1 = new javax.swing.JLabel();
jLabel2 = new javax.swing.JLabel();
jLabel3 = new javax.swing.JLabel();
setDefaultCloseOperation(javax.swing.WindowConstants.DISPOSE_ON_CLOSE);
setTitle("Data Normalisation");
jTable1.setAutoCreateRowSorter(true);
jTable1.setCellSelectionEnabled(true);
jScrollPane1.setViewportView(jTable1);
// Variables declaration - do not modify
private javax.swing.JButton jButton1;
private javax.swing.JButton jButton2;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JTable jTable1;
// End of variables declaration
class DataModel extends AbstractTableModel {       
class TML implements TableModelListener{
public void tableChanged (TableModelEvent e){
txt.setText(""); // Clear it
for (int i=0;i<DataSummary.length; i++){
for (int j=0; j<DataSummary[0].length;j++){
txt.append(DataSummary[i][j] + " ");
txt.append("\n");
public DataModel(){
addTableModelListener(new TML());
@Override
public void setValueAt(Object val, int row, int col){
DataSummary[row][col]=val;
fireTableDataChanged();
@Override
public boolean isCellEditable(int row, int col){
return (col != 0);
public int getRowCount(){
return DataSummary.length;
public int getColumnCount(){
return colName.size();
public Object getValueAt(int row, int column){   
return DataSummary[row][column];
public String getColumnName(int col) {           
return colName.get(col);
class CustomTableCellRenderer extends DefaultTableCellRenderer {       
@Override
public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected,
boolean hasFocus, int row, int column) {
Component cell = super.getTableCellRendererComponent(table, value, isSelected, hasFocus, row, column);
if (value == null || value.equals("")) {
cell.setBackground(Color.red);
} else cell.setBackground(Color.white);
return cell;

Answer 1

Ideally I would like the cell to keep its color when clicked or double-clicked Not sure why is changes color when you click on the cell.
But when you double click the editor is invoked, which is a JTextField and its background is white by default.
The code you posted doesn't help because its not executable.
If you need further help then you need to create a [Short, Self Contained, Compilable and Executable, Example Program (SSCCE)|http://homepage1.nifty.com/algafield/sscce.html], that demonstrates the incorrect behaviour.
And don't post NetBeans generated code, because we don't use IDE to write GUI code.
Also, why did you create a custom TableModel. The DefaultTableModel will store your data for you.