If I set a JTable's data array to be n elements wide and 0 long (so it
can still have column headers, but no data) I get an exception:
java.lang.ArrayIndexOutOfBoundsException: 0 >= 0
        at java.util.Vector.elementAt(Vector.java)
        at com.sun.java.swing.table.DefaultTableModel.setDataVector(DefaultTableModel.java:331)
        at com.sun.java.swing.table.DefaultTableModel.setDataVector(DefaultTableModel.java:368)
        at com.sun.java.swing.table.DefaultTableModel.<init>(DefaultTableModel.java:213)
        at com.sun.java.swing.JTable.<init>(JTable.java:271)
        at ZeroLengthJTableTest.<init>(ZeroLengthJTableTest.java:27)
        at ZeroLengthJTableTest.main(ZeroLengthJTableTest.java:12)

Here is the users code for reproducing:
import java.awt.*;
import com.sun.java.swing.*;

public class ZeroLengthJTableTest
extends Frame
{
  public static void main(String args[])
  {
    ZeroLengthJTableTest t = new ZeroLengthJTableTest();
    t.show();
  }

  public ZeroLengthJTableTest()
  {
    setTitle("Zero length data JTableTest...");
    setSize(300, 400);
    setLayout(new BorderLayout());

    String colnames[] = {"foo", "bar", "baz"};
    String data[][] = new String[0][3];

    JTable t = new JTable(data, colnames);
    add(JTable.createScrollPaneForTable(t), "Center");
  }
}