How do I set background color of cell using JTable?

Question

Hello all!
I have a question on the use of JTables. I am using a JDialog consisting of a JTable and a number of buttons to insert and to select OK or cancel. Everything is working perfectly, but I now must add editing capabilities to prevent invalid data being used in a SQL query to update or insert rows.
So far I can't figure out how to get at a cell to set the background to red if the user inputs a Date incorrectly. Upon setValueAt(), I take this value and check for standard format errors. I hope to someday convert the column altogether to a Data object (or some form since Date is deprecated):-) For the time being, I know when an error occurs, but don't have the foggiest idea how to render the error (set backround to red).
I need to give you more info too, since the way we do things is to make it as complicated as possible for job security and to impress the newbies(or scare them back to COBOL). When I setValueAt(), I have a DefaultDataElement object that houses everything for a given column in DB2. It has column name, length, data type, is it new, original value, current value, etc. If one doesn't exist, then I create one. After all said and done, I parse thru these elements and build my update/insert query and then execute the query.
The event starts as soon as the user presses the OK button. But, if a date cell contains an invalid date, I need to halt processing (which I've done) and somehow let the user know which cell was invalid. We consider our users dumb (they really aren't, but the assumption is made), so I can't just say "error occurred in table. Verify data and try again". That won't work:-) Gotta be able to show them what cell is bad.
Any ideas?
Thanks,
Patrick

Answer 1

I finally figured it out. I was always close, but it wasn't until late yesterday that the light bulb came on. I was setting the background on the component in getTableCellEditorComponent() by grabbing the super.getTableCellEditorComponent(). The problem was all this was located in an editor, not renderer. So what happened was as I edited the cell the check would be performed then, not as focus was lost. When focus was lost, the red background went back to normal.
I ripped the code out and made a custom renderer and got closer. Problem was the whole column had a red background. Even specifying the row and column in getTableCellRendererComponent didn't apply just to that cell. That row and column is only for obtaining the data in the cell, but anything affecting the component will affect the column, since I added the renderer to my TableColumn:-) I need to add error logic to my model and when an error occurs, set a boolean flag in a 2 dimensional array where the row and column is used to get to it from the renderer.
Thanks for the help!!!