Validating and highlighting JTable Cell

Question

I am highlighting JTable cells based on validation. In some conditions, I have to take the value of other columns. For example, if column2 has USA then column3 should be only numeric. As another example, if col2 is "USA" and col4 is numeric, then col5 should be only three chars. Can someone suggest how this can be done?

In the fragment below, col3 contains country names; col4 and col5 depend on col3. When I am in case 3 and in case 4, I cannot check the value of case 2. For example, I want like, if (col3.value == "USA").

    [code]
    tcol = editorTable.getColumnModel().getColumn(0);
    tcol.setCellRenderer(new CustomTableCellRenderer());

    tcol = editorTable.getColumnModel().getColumn(1);
    tcol.setCellRenderer(new CustomTableCellRenderer());

    tcol = editorTable.getColumnModel().getColumn(2);
    tcol.setCellRenderer(new CustomTableCellRenderer());

    public class CustomTableCellRenderer extends DefaultTableCellRenderer {
        @Override
        public Component getTableCellRendererComponent (JTable table, Object
        value,boolean isSelected, boolean hasFocus, int row, int col){

        Component cell = super.getTableCellRendererComponent(table, value,
        isSelected,hasFocus, row, col);

       if (value instanceof String) {
           String str = (String) value;

           switch (col) {
                case 0:
                    col1(str, cell);
                    break;
                case 1:
                    col2(str, cell);
                    break;
                case 2:
                    col3(str, cell);
                    break; 
           }
        }
        return cell;
     }

      private void col1(String str, Component cell) {       
            if(!str.matches("[0-9a-zA-z]")){
                cell.setBackground(Color.RED);
            } else {
                cell.setBackground(Color.GREEN); 
           }
     }

      private void col2(String str, Component cell) {       
         if(!str.matches("[A-Z]{3}")){
             cell.setBackground(Color.RED);
         } else {
              cell.setBackground(Color.GREEN); 
         }
     }
    [/code]

what exactly is the problem? simply express your deescription in code ... BTW: beware that the row/column coordinates area _view_ - before basing any model-related logic on them, you'll have to convert them — kleopatra, Feb 18 '12 at 10:07
1) use `prepareRenderer` 2) remove `switch (col) {` 3) [simplify code](http://stackoverflow.com/questions/7132400/jtable-row-hightlighter-based-on-value-from-tablecell) or [here](http://stackoverflow.com/questions/6410839/highlights-substring-in-the-tablecells-which-is-using-for-jtable-filetering) — mKorbel, Feb 18 '12 at 10:43
mKorbel, if i am not wrong, prepareRenderer needs looping of all the rows right? Is it not possible with the current renderer. I just should be able to get the values of other columns. Thanks — FirmView, Feb 18 '12 at 13:52
1) use prepareRenderer 2) remove switch (col) { 3) switch of ColumnReordering for ColumnRenderer, 4) your Renderer must be called after any changes in the model or view, 5) have to check convertXxxIndexToXxx() — mKorbel, Feb 18 '12 at 14:22
Please edit your question to include an [sscce](http://sscce.org/). — trashgod, Feb 18 '12 at 16:06

score 2 · Accepted Answer · edited May 23 '17 at 11:48

@kleopatra and @mKorbel are correct. Your fragment is incomplete, but it appears as if you are trying to solve editor and model problems in the renderer.

You can validate entered values in a custom TableCellEditor, as shown in this example. You can handle dependent columns in the TableModel, as shown in this example.

In a comment you say, "If I am not wrong, prepareRenderer() needs looping of all the rows, right?"

No, JTable "internal implementations always use this method to prepare renderers so that this default behavior can be safely overridden by a subclass." Overriding prepareRenderer() is most useful when changes must be be selectively applied to all renderers.

See Concepts: Editors and Renderers for more details.

Validating and highlighting JTable Cell

1 Answers1