String index out of bound exception in JTable

I used JTable to update records in a table. In the following code, I am getting
java.lang.StringIndexOutOfBoundsException: String index out of range: -1
exception in the line :
table = new JTable(this);

However, this is happening ONLY for the table 'Triangle' and not for the other tables. What could be wrong ???

Can you perhaps show the entire stack trace? There is something in the table model, but without that code or the stack trace it's impossible to know what.

This is the only line that is shown as error while executing that class file. :-(

But without the stack trace we still can't see what exactly is going wrong. There are quite a lot of method calls from the JTable constructors that it's hard to see what exactly goes wrong just by looking at this code.

This is the complete code of the .java file. I have a table Triangle in Microsoft access DB. It has 14 columns

import java.awt.*;
import java.io.*;
import java.sql.*;
import java.util.*;
import javax.swing.*;
import java.awt.event.*;
import javax.swing.table.*;
import javax.swing.JTable;
import java.text.MessageFormat;
import javax.swing.table.AbstractTableModel;

class ScoreEdit extends AbstractTableModel
{  
	private ResultSetMetaData rsmd;
ResultSet rs;
Connection conn;
Statement stat;
JTable table = null;
JScrollPane scrollPane;
JPanel pane;

public ScoreEdit(  )
{

TableColumn column = null;
final JFrame frame = new JFrame("Player Entry Screen");
 JButton bExit = new JButton("Exit");
 bExit.setMnemonic(KeyEvent.VK_X);

try
   {  
	   	  conn  = BridgeConnect.getThinConnection();
           stat = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,
                             ResultSet.CONCUR_UPDATABLE);
           rs = stat.executeQuery("SELECT * FROM Triangle" );

rsmd = rs.getMetaData();
	  System.out.println("Column count : " + rsmd.getColumnCount() );

table = new JTable(this);
 
			for (int i = 0; i < 4; i++) 
				{
				    column = table.getColumnModel().getColumn(i);
				    if (i == 3) 
						{
	//					System.out.println("Changing width of the column");
				        column.setPreferredWidth(100); //Fourth column is bigger
					    } 
					else 
						{
				        column.setPreferredWidth(10);
					    }
				} // for

table.setColumnSelectionAllowed(true);
           table.setRowSelectionAllowed(true);
           scrollPane = new JScrollPane(table );
		   scrollPane.setPreferredSize(new Dimension(700, 500));

pane = new JPanel();
           pane.add(scrollPane, BorderLayout.CENTER);
		   
			
			pane.setSize(700,700);
			
			pane.add(bExit, BorderLayout.SOUTH);

frame.getContentPane().add(pane);
			frame.setResizable(false);
		frame.setLocation(0, 0);
       frame.setSize(700,600);
	   frame.pack();
	 //  frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
		   frame.setVisible(true);
   }
   catch (SQLException e)
   {  
      System.out.println("SQL Exception : " + e);
   } // catch
   catch (Exception ex)
	{
	   System.out.println("Exception : " + ex);
	} // catch

frame.addWindowListener(new WindowAdapter()
		{
			public void windowClosing(WindowEvent e)
			{
				MainScreen.bPlayerEntered = true;
				e.getWindow().dispose();
			}
		});

bExit.addActionListener(new ActionListener()
		{
			public void actionPerformed(ActionEvent e)
			{
				// Close this screen only
				MainScreen.bPlayerEntered = true;
				frame.dispose();

}
		});

} // Constructor

public String getColumnName(int c)
{  
	String colname="";
	int pos=0;
   try
   {  
	   colname = rsmd.getColumnName(c + 1);
	   pos = colname.indexOf("_");
	   colname = colname.substring(0,pos) + " " + colname.substring(pos+1) ;

}
   catch (SQLException e)
   {  
      System.out.println("Exception in getColumnName method : " + e);
   }
   return colname;
}

public boolean isCellEditable(int row, int col)
	{
  // 	  System.out.println("Row = " + row + " Col = " + col);
	  if (col == 3)
	  {
		  return true;
	  }
      return false;
}

public int getColumnCount()
{  
   try
   {  
      return rsmd.getColumnCount();
   }
   catch (SQLException e)
   {  
      e.printStackTrace();
      return 0;
   }
}

public Object getValueAt(int r, int c)
{  
   try
   {  
      rs.absolute(r + 1);
      return  rs.getObject(c + 1);
   }
   catch(SQLException e)
   {  
      e.printStackTrace();
      return null;
   }
}

public void setValueAt(Object aValue, int rowIndex, int columnIndex)
	{
	String str = (String) aValue;
      try
         {  
            rs.absolute(rowIndex + 1);
     //     System.out.println("row: "+ rowIndex + ", col:" + columnIndex + " Value = " + str);
            rs.updateString(columnIndex+1, str);
            rs.updateRow();
         }
         catch(SQLException e)
         {  
            e.printStackTrace();
         }
}

public int getRowCount()
{  
   try
   {  
      rs.last();
      return rs.getRow();
   }
   catch(SQLException e)
   {  
      e.printStackTrace();
      return 0;
   }
}

public static void main (String args[] )
	{
	
		ScoreEdit pe = new ScoreEdit();

} // method main 
}

the culprit is likely to be in this bit

in particular these 2 lines
pos = colname.indexOf("_");
colname = colname.substring(0,pos) + " " + colname.substring(pos+1) ;

if there is not a '_' in colname, pos = -1, and you will get the exception you see.

try it this way, and see if it fixes the problem

Thanks a lot.
It is working now.