Java.io.NotSerializableException when overwrite the JTable data into .txt file

Question

hi everyone
this is my first time to get help from sun forums
i had java.io.NotSerializableException: java.lang.reflect.Constructor error when overwrite the JTable data into .txt file.
At the beginning, the code will be generate successfully and the jtable will be showing out with the data that been save in the studio1.txt previously,
but after i edit the data at the JTable, and when i trying to click the save button, the error had been showing out and i cannot succeed to save the JTable with the latest data.
After this error, the code can't be run again and i had to copy the studio1.txt again to let the code run 1 more time.
I hope i can get any solution at here and this will be very useful for me.
the following is my code...some of it i create it with the GUI netbean
but i dunno how to attach my .txt file with this forum
did anyone need the .txt file?
this is the code that suspect maybe some error here
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
String filename = "studio1.txt";
          try {
              FileOutputStream fos = new FileOutputStream(new File(filename));
              ObjectOutputStream oos = new ObjectOutputStream(fos);
               oos.writeObject(jTable2);
               oos.close();
          catch(IOException e) {
               System.out.println("Problem creating table file: " + e);
               return;
          System.out.println("JTable correctly saved to file " + filename);
}the full code will be at the next msg

Answer 1

this is the part 1 of the code
this is the full code...i had /*....*/ some of it to make it easier for reading
package gui;
import javax.swing.*;
import java.io.*;
public class timetables extends javax.swing.JFrame {
    public timetables() {
        initComponents();
    @SuppressWarnings("unchecked")
    private void initComponents() {
        jDialog1 = new javax.swing.JDialog();
        buttonGroup1 = new javax.swing.ButtonGroup();
        buttonGroup2 = new javax.swing.ButtonGroup();
        buttonGroup3 = new javax.swing.ButtonGroup();
        buttonGroup4 = new javax.swing.ButtonGroup();
        jTextField1 = new javax.swing.JTextField();
        jLayeredPane1 = new javax.swing.JLayeredPane();
        jLabel6 = new javax.swing.JLabel();
        jTabbedPane1 = new javax.swing.JTabbedPane();
        jScrollPane3 = new javax.swing.JScrollPane();
        jTable2 = new javax.swing.JTable();
        jScrollPane4 = new javax.swing.JScrollPane();
        jTable3 = new javax.swing.JTable();
        jButton1 = new javax.swing.JButton();
        jButton2 = new javax.swing.JButton();
/*       org.jdesktop.layout.GroupLayout jDialog1Layout = new org.jdesktop.layout.GroupLayout(jDialog1.getContentPane());
        jDialog1.getContentPane().setLayout(jDialog1Layout);
        jDialog1Layout.setHorizontalGroup(
            jDialog1Layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
            .add(0, 400, Short.MAX_VALUE)
        jDialog1Layout.setVerticalGroup(
            jDialog1Layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
            .add(0, 300, Short.MAX_VALUE)
        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
        jLayeredPane1.add(jLabel6, javax.swing.JLayeredPane.DEFAULT_LAYER);
        String filename1 = "studio1.txt";
        try {
               ObjectInputStream ois = new ObjectInputStream(new FileInputStream(filename1));
               jTable2 = (JTable) ois.readObject();
               System.out.println("reading for " + filename1);
          catch(Exception e) {
               System.out.println("Problem reading back table from file: " + filename1);
               return;
        try {
               ObjectInputStream ois = new ObjectInputStream(new FileInputStream(filename1));
               jTable3 = (JTable) ois.readObject();
               System.out.println("reading for " + filename1);
          catch(Exception e) {
               System.out.println("Problem reading back table from file: " + filename1);
               return;
        jTable2.setRowHeight(20);
        jTable3.setRowHeight(20);
        jScrollPane3.setViewportView(jTable2);
        jScrollPane4.setViewportView(jTable3);
        jTable2.getColumnModel().getColumn(4).setResizable(false);
        jTable3.getColumnModel().getColumn(4).setResizable(false);
        jTabbedPane1.addTab("STUDIO 1", jScrollPane3);
        jTabbedPane1.addTab("STUDIO 2", jScrollPane4);
        jTextField1.setText("again n again");
        jLabel6.setText("jLabel5");
        jLabel6.setBounds(0, 0, -1, -1);
        jButton2.setText("jButton2");
        jButton1.setText("jButton1");
        jButton1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton1ActionPerformed(evt);