Defining Column Header Of JTable

I am making a gui in which i read values from text file to JTable. But i want to define the column header as A,B,C,D,E,F,G,H,I. Now when i read, the values from text file are getting displayed in Jtable headers. How can i achieve the column header as A,B,C,D,E,F,G,H,I.

import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.util.*;
import javax.swing.*;
import javax.swing.table.*;
public class Bb extends JFrame {

[Code] ......

Text file from where it reads values: bbb.txt

1 2 1 1 2 1 1.83e-02 -1.0 3
1 1 1 1 1 1 1.89e-02 -1.0 2
0 0 0 0 0 0 0 0 0
1 2 1 1 2 1 1.83e-02 -1.0 3
1 1 1 1 1 1 1.83e-02 -1.0 2