How Can I set up a JTable columns?

Question

Dear All,
How can I set up my JTable columns to have the amount the user specifies?
for example when the user types in 50 in JTextField 1 I want the JTables columns to then set to 50.
How can this be done?
Thanks
lol
import javax.swing.*;
import javax.swing.table.TableModel;
import java.io.*;
import java.util.*;
import java.lang.*;
import java.awt.*;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
public class si1 extends javax.swing.JFrame implements ActionListener {
    JTextField name = new JTextField(15);
    JTextField name1 = new JTextField(15);
    public si1() {
        super("DataBase Loader");
        setSize(1025,740);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JPanel pane = new JPanel();
        JPanel pane1 = new JPanel();
        JPanel pane2 = new JPanel();
        JPanel pane3 = new JPanel();
        JPanel pane4 = new JPanel();
        pane.setLayout(new GridLayout(20,1));
        pane1.setLayout(new BorderLayout());
        int j=10;
        String[][] data = new String[j][2];
        for (int k=0; k<j; k++){
           String[] row = {"",""};
           data[k] = row;
        String[] columnNames = {"First Name", "Last Name"};
        JTable perstab = new JTable(data, columnNames);
        perstab.setGridColor(Color.yellow);
        perstab.setPreferredScrollableViewportSize(new Dimension(500,500));
        JScrollPane scrollPane = new JScrollPane(perstab);
        pane1.add(new JPanel(), BorderLayout.EAST);
        JButton btn = new JButton("What are the names?");
        btn.addActionListener(this);
        btn.putClientProperty("DATABASE", perstab);
        pane1.add(new JPanel().add(btn), BorderLayout.SOUTH);
        pane2.add(name);
        pane3.add(name1);
        pane.add(pane2);
        pane.add(pane3);
        pane1.add(pane, BorderLayout.WEST);
        pane4.add(scrollPane);
        pane1.add(pane4, BorderLayout.CENTER);
        setContentPane(pane1);
        show();
    public static void main(String[] args) {
        si1 frame = new si1();
        frame.setVisible(true);
    public void actionPerformed(ActionEvent e) {
        JTable table = (JTable)((JButton)e.getSource()).getClientProperty("DATABASE");
        TableModel model = table.getModel();
        int count = model.getRowCount();
        String[] firstnames = new String[count];
        String[] lastnames = new String[count];
        for (int i=0; i < count; i++) {
           firstnames[i] = (String)model.getValueAt(i, 0);
            System.out.println("first name at row " + i + ": " + firstnames);
lastnames[i] = (String)model.getValueAt(i, 1);
System.out.println("lastname name at row " + i + ": " + lastnames[i]);

Answer 1

As you can see I have tried this, but no success.
If I am doing something wrong please accept my apology, and address me in the right direction.
Thanks
Lol
import javax.swing.*;
import javax.swing.table.TableModel;
import java.io.*;
import java.util.*;
import java.lang.*;
import java.awt.*;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
public class si1 extends javax.swing.JFrame implements ActionListener {
    JTextField name = new JTextField(15);
    JTextField name1 = new JTextField(15);
    public si1() {
        super("DataBase Loader");
        setSize(1025,740);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JPanel pane = new JPanel();
        JPanel pane1 = new JPanel();
        JPanel pane2 = new JPanel();
        JPanel pane3 = new JPanel();
        JPanel pane4 = new JPanel();
        pane.setLayout(new GridLayout(20,1));
        pane1.setLayout(new BorderLayout());
        int j=10;
        String[][] data = new String[j][2];
        for (int k=0; k<j; k++){
           String[] row = {"",""};
           data[k] = row;
        String[] columnNames = {"First Name", "Last Name"};
        JTable perstab = new JTable(data, columnNames);
     ((DefaultTableModel)perstab.getModel()).setColumnCount(Integer.parseInt(name.getText()));
        perstab.setGridColor(Color.yellow);
        perstab.setPreferredScrollableViewportSize(new Dimension(500,500));
        JScrollPane scrollPane = new JScrollPane(perstab);
        pane1.add(new JPanel(), BorderLayout.EAST);
        JButton btn = new JButton("What are the names?");
        btn.addActionListener(this);
        btn.putClientProperty("DATABASE", perstab);
        pane1.add(new JPanel().add(btn), BorderLayout.SOUTH);
        pane2.add(name);
        pane3.add(name1);
        pane.add(pane2);
        pane.add(pane3);
        pane1.add(pane, BorderLayout.WEST);
        pane4.add(scrollPane);
        pane1.add(pane4, BorderLayout.CENTER);
        setContentPane(pane1);
        show();
    public static void main(String[] args) {
        si1 frame = new si1();
        frame.setVisible(true);
    public void actionPerformed(ActionEvent e) {
        JTable table = (JTable)((JButton)e.getSource()).getClientProperty("DATABASE");
        TableModel model = table.getModel();
        int count = model.getRowCount();
        String[] firstnames = new String[count];
        String[] lastnames = new String[count];
        for (int i=0; i < count; i++) {
           firstnames[i] = (String)model.getValueAt(i, 0);
            System.out.println("first name at row " + i + ": " + firstnames);
lastnames[i] = (String)model.getValueAt(i, 1);
System.out.println("lastname name at row " + i + ": " + lastnames[i]);