Strange ClassCastException working with JTable

[Blake Minghelli]

Well, I've had all kinds of difficulties working with JTable so far.
I am working with a very simple table. Originally, I constructed it like this:

Vector colNames = new Vector();
... // add columns to Vector
Vector nullRows = null;
JTable resultsTable = new JTable(nullRows , colNames);
  

The data is not known at the time of construction which is why I was passing a null Vector for the dataRows param.
That code worked fine from my PC but the JTable constructor threw NullPointerExceptions on another PC. Both PCs were running java 1.4.2_05.

So, since one JVM seemed to not like the null dataRows, I created an empty dataRows Vector, like this::

Vector colNames = new Vector();
... // add columns to Vector
Vector emptyRows = new Vector(); // Just an empty Vector
emptyRows.add(new Vector());
JTable resultsTable = new JTable(emptyRows, colNames);
  

That fixed the NPE's and both PC's seemed to be happy.

However, now I am running into another strange problem with this code:

private void clearTable (JTable table) {
((DefaultTableModel)table.getModel()).setRowCount(0);
}

As you can see the intent is to simply remove all rows from a table. But on [B]one[B] PC, I am getting a ClassCastException in that method. On the other PC, it works fine.

Anyone experience this?
Why would table.getModel() on one PC using the same JRE return something other than DefaultTableModel???

[Barry Andrews]

Are you absolutely sure both machines are running the same Java version? If you run java -version on the command line, you get the same?

[Blake Minghelli]

Originally posted by Barry Andrews:
Are you absolutely sure both machines are running the same Java version? If you run java -version on the command line, you get the same?

Correct.
Even if the version was slightly different, I don't see why the cast would break. As far as I understand TableModel usage, if you don't explicitly use one (e.g. if you use the JTable(Vector, Vector) constructor), then you get a DefaultTableModel. Arghhhh

[Serghei Jelauc]

Hi. Do not know if it help you, but vector which contains the table data must be Vector of Vectors(every Vector inside must represent one row in the table), in other way DeafaultDataModel will not understand this construction.
[ July 20, 2004: Message edited by: Serghei Jelauc ]