How to pass external input to user-defined subclasses???

[Lorenzo]

Hi all,

[this might be a really trivial question] I would like to define a sub-
class of JTable which get some external inputs: something similar to
the following *not-working* example.

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*****
import javax.swing.*;
import javax.swing.table.*;

public class RHJTable extends JTable
{
public RHJTable(int rows, int columns, int externalinput)
{
super(rows, columns);
}
public Object getValueAt(int row, int column, int externalinput)
{
return externalinput;
}
}
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*****

What follows is the error message I get, which I assume it is due to
my "externalinput":

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*****
??? Java exception occurred:
java.lang.ArrayIndexOutOfBoundsException: 0 >= 0

at java.util.Vector.elementAt(Unknown Source)
at javax.swing.table.DefaultTableColumnModel.getColumn(Unknown
Source)
at javax.swing.JTable.getCellRect(Unknown Source)
at javax.swing.JTable.valueChanged(Unknown Source)
at javax.swing.DefaultListSelectionModel.fireValueChanged(Unknown
Source)
at javax.swing.DefaultListSelectionModel.fireValueChanged(Unknown
Source)
at javax.swing.DefaultListSelectionModel.fireValueChanged(Unknown
Source)
at javax.swing.DefaultListSelectionModel.changeSelection(Unknown
Source)
at javax.swing.DefaultListSelectionModel.changeSelection(Unknown
Source)
at
javax.swing.DefaultListSelectionModel.removeSelectionIntervalImpl(Unkno
wn Source)
at
javax.swing.DefaultListSelectionModel.removeSelectionInterval(Unknown
Source)
at javax.swing.JTable.checkLeadAnchor(Unknown Source)
at javax.swing.JTable.tableChanged(Unknown Source)
at javax.swing.JTable.setModel(Unknown Source)

at javax.swing.JTable.<init>(Unknown Source)
at javax.swing.JTable.<init>(Unknown Source)
at javax.swing.JTable.<init>(Unknown Source)
at RHJTable.<init>(RHJTable.java:12)
***********************************************************************
*****

Can anybody please suggest me the correct way of passing this external
input?

Thanks


lor