Very Urgent, files, threads, and swing !!!!

Question

Dear friends, i have a swing application, in that application i have a class that extends a thread, that thread will do nothing but read the contents of my data file and puts them in an array, but i am getting a NullpointerException in my thread, could any friend help me please, it is very urgent, i will post my code below.
import java.awt.*;
import java.awt.event.*;
import java.text.DateFormat;
import java.util.*;
import javax.swing.*;
import java.sql.*;
import java.net.URL;
import java.io.*;
public class FinalMachine extends JFrame
private JPanel MainPanel, ThicknessPanel, MainManager,fieldsPanel, sub_panel;
private Container c;
private CardLayout CardManager;
private String timezone;
private static final int ONE_SECOND = 1000;
private JLabel welcome_label, label1, label2, label3,field_label;
private JTextField data_entry;
private Connection connection;
public JPanel thick_figure;
public int num_of_hits, next_index, recCount;
public int dataBuffer[];
public FileReader data_file;
public BufferedReader b_data_file;
public File tem_file;
final int num_of_rec = 20;
public FinalMachine()
super("PHOENIX MACHINERY s.a.l");
/* Start all threads */
/* Start filling data file in global array */
     loadData dataFile = new loadData();
     dataFile.start();          
/* Adding control to window application */
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent windowevent)
// setDefaultCloseOperation(0);
          System.exit(0);
public void windowDeiconified(WindowEvent eve)
setState(0);
addComponentListener(new ComponentAdapter() {
public void componentResized(ComponentEvent componentevent)
setSize(500, 500);
Dimension dimension1 = Toolkit.getDefaultToolkit().getScreenSize();
if(dimension1.width == 800 && dimension1.height == 600)
setLocation(150, 25);
else
if(dimension1.width == 1024 && dimension1.height == 768)
setLocation(200, 100);
/* Setting the location of the application on the screen */
Dimension dimension = Toolkit.getDefaultToolkit().getScreenSize();
if(dimension.width == 800 && dimension.height == 600)
setLocation(150, 25);
else
if(dimension.width == 1024 && dimension.height == 768)
setLocation(200, 100);
/* Constructing the main menu */
     JMenuBar bar = new JMenuBar();
     setJMenuBar( bar );
     JMenu fileMenu = new JMenu( "File");
     fileMenu.setMnemonic( 'F' );
     JMenuItem mainItem = new JMenuItem( "Main page" );
     mainItem.setMnemonic( 'M' );
     mainItem.addActionListener (
          new ActionListener() {
               public void actionPerformed( ActionEvent e )
               CardManager.show(MainManager, "main");
     fileMenu.add( mainItem );
     JMenuItem dataItem = new JMenuItem( "Database page" );
     dataItem.setMnemonic( 'D' );
     dataItem.addActionListener (
          new ActionListener() {
               public void actionPerformed( ActionEvent e )
               CardManager.show(MainManager, "data_base");
     fileMenu.add( dataItem );
     JMenuItem printItem = new JMenuItem( "Print" );
     printItem.setMnemonic( 'P' );
     printItem.addActionListener (
          new ActionListener() {
               public void actionPerformed( ActionEvent e )
               PrintUtilities.printComponent(MainManager);
     fileMenu.add( printItem );
     JMenuItem exitItem = new JMenuItem( "Exit" );
     exitItem.setMnemonic( 'P' );
     exitItem.addActionListener (
          new ActionListener() {
               public void actionPerformed( ActionEvent e )
                    System.exit(0);
     fileMenu.add( exitItem );
     bar.add( fileMenu );
     JMenu figureMenu = new JMenu( "Figures");
     figureMenu.setMnemonic( 'G' );
     JMenuItem thicknessItem = new JMenuItem( "Thickness" );
     thicknessItem.setMnemonic( 'T' );
     thicknessItem.addActionListener (
          new ActionListener() {
               public void actionPerformed( ActionEvent e )
               CardManager.show(MainManager, "thickness");
     figureMenu.add( thicknessItem );
     bar.add( figureMenu );
     JMenu helpMenu = new JMenu( "Help");
     helpMenu.setMnemonic( 'H' );
     JMenuItem aboutItem = new JMenuItem( "About us" );
     aboutItem.setMnemonic( 'A' );
     aboutItem.addActionListener (
          new ActionListener() {
               public void actionPerformed( ActionEvent e )
               JOptionPane.showMessageDialog(null, "Engineer Bilal Haidar (Computer & "+                     "Communication Engineering)\n\n All Rights Reserevd. @ 2002",
                    "About me...", JOptionPane.PLAIN_MESSAGE);
     helpMenu.add( aboutItem );
     bar.add( helpMenu );
/* Intializing global values */
dataBuffer = new int[60];
/* Initializing the panels */
c = getContentPane();
c.setLayout(new FlowLayout());
CardManager = new CardLayout();
MainManager = new JPanel(false);
MainManager.setLayout(CardManager);
c.add(MainManager);
javax.swing.border.Border border = BorderFactory.createEmptyBorder(10, 10, 5, 10);
MainPanel = new JPanel(false);
MainPanel.setLayout(new BoxLayout(MainPanel, 1));
MainPanel.setBorder(border);
ThicknessPanel = new JPanel(false);
ThicknessPanel.setLayout(new BoxLayout(ThicknessPanel, 1));
ThicknessPanel.setBorder(border);
fieldsPanel = new JPanel(false);
fieldsPanel.setLayout( new BoxLayout( fieldsPanel,1));
fieldsPanel.setBorder(border);
sub_panel = new JPanel(false);
sub_panel.setLayout( new BoxLayout(sub_panel,0) );
sub_panel.setBorder(border);
thick_figure = new JPanel(false);
thick_figure.setBorder(border);
/* Filling the main panel */
JLabel jlmain = new JLabel("Main Page");
MainPanel.add(jlmain);
timezone = showTime(new Locale("en", "US"));
JLabel jltime = new JLabel(" " + timezone);
MainPanel.add(jltime);
MainManager.add(MainPanel, "main");
/* Filling the thickness panel */
num_of_hits = 0;
next_index = 0;
/* fill in with ero values for everything*/
/*display the figure*/
ThicknessPanel.add(thick_figure);
JLabel blanklabel = new JLabel(" ");
ThicknessPanel.add(blanklabel);
JButton build_fig = new JButton("Draw Figure");
build_fig.addActionListener(
     new ActionListener() {  // anonymous inner class
     public void actionPerformed( ActionEvent e )
if ( num_of_hits == 0 )
/* draw figure based on first 20 points in the array */
next_index = num_of_rec;
else
if ( num_of_hits > 3 )
JOptionPane.showMessageDialog(null,"No more data to draw","Error Drawing",JOptionPane.ERROR_MESSAGE);
else
/* draw the figure starting the data from index 20*/
next_index = next_index + num_of_rec;
num_of_hits += 1;
ThicknessPanel.add(build_fig);
MainManager.add(ThicknessPanel, "thickness");
/* filling the database panel */
label1 = new JLabel(" ",SwingConstants.CENTER);
welcome_label = new JLabel(" Database Page ",SwingConstants.CENTER);
label2 = new JLabel(" ",SwingConstants.CENTER);
fieldsPanel.add( label1 );
fieldsPanel.add( welcome_label );
fieldsPanel.add( label2 );
field_label = new JLabel(" Enter your name: ");
data_entry = new JTextField( 10 );
sub_panel.add( field_label );
sub_panel.add( data_entry );
fieldsPanel.add( sub_panel );
JButton add_data = new JButton( "Add me" );
add_data.addActionListener(
     new ActionListener() {  // anonymous inner class
     public void actionPerformed( ActionEvent e )
// try {
//          url = "jdbc:odbc:DataEntry";
//          Class.forName( "sun.jdbc.odbc.JdbcOdbcDriver" );
//          connection = DriverManager.getConnection( url );
//               System.out.println( "Connection Suucessfull");
// Statement statement = connection.createStatement();
//                String get_field;
//               get_field = data_entry.getText();
//               String query = "INSERT INTO data (anyField) VALUES ('get_field')";
//                int result1 = statement.executeUpdate( query );
//           if ( result1 == 1 )
// JOptionPane.showMessageDialog(null, "Thanks for the info..."," Data Entry Success",JOptionPane.INFORMATION_MESSAGE);
//                else
//                     JOptionPane.showMessageDialog(null, "Sorry, your name was not added...","Data entry error",JOptionPane.ERROR_MESSAGE);
//     catch ( ClassNotFoundException cnfex ) {
//          // process ClassNotFoundExceptions here
//          cnfex.printStackTrace();
//               System.out.println( "Connection UN Suucessfull");
//          catch ( SQLException sqlex ) {
//     // process SQLExceptions here
//          sqlex.printStackTrace();
//                System.out.println( "Connection UN Suucessfull");
//          catch ( Exception ex ) {
//          // process remaining Exceptions here
//          ex.printStackTrace();
//               System.out.println( "Connection UN Suucessfull");
fieldsPanel.add(add_data);
MainManager.add(fieldsPanel, "data_base");
/* display time */
Timer timer = new Timer(1000, new ActionListener() {
public void actionPerformed(ActionEvent actionevent)
timezone = showTime(new Locale("en", "US"));
setTitle("PHOENIX MACHINERY s.a.l " + timezone);
timer.start();
public static void main(String args[])
FinalMachine finalmachine = new FinalMachine();
finalmachine.setSize(500, 500);
ImageIcon imageicon = new ImageIcon("images/pc.gif");
finalmachine.setIconImage(imageicon.getImage());
finalmachine.show();
public static String showTime(Locale locale)
java.util.Date date = new java.util.Date();
byte byte0 = 2;
DateFormat dateformat = DateFormat.getTimeInstance(byte0, locale);
String s = dateformat.format(date);
return s;
/* Thread loadData starts here */
class loadData extends Thread
public void run()
try {
          readMyFile();
catch( Exception x )
System.out.println("The following error occured in LoadData thread : "+x.toString() ); }
} // run() ends here
/* method read file inside thread loadData */
void readMyFile() {
String record = " ";
recCount = 0;
try {
          tem_file = new File("mydata.dat");
          data_file = new FileReader(tem_file);
          b_data_file = new BufferedReader( data_file );
          record = new String();
          while ( (record = b_data_file.readLine()) != null ) {
          dataBuffer[recCount] = Integer.parseInt(record);
          recCount += 1; }
     b_data_file.close();     
          catch (IOException e) {
     System.out.println("Uh oh, got an IOException error!");
     e.printStackTrace();
     } // end of readMyFile()
} // thread loadData ends
mydata.dat
2
4
3
1
2
3
5
2
4
1
6
3
2
5
4
1
2
5
8
2
6
9
7
4
2
1
0
2
5
4
8
7
5
6
3
2
1
4
3
0
2
3
6
5
2
1
4
5
6
9
8
5
2
1
6
8
3
1
7
5

Answer 1

Thank you Mr. jobuck, you helped me a lot, i wonder if you can provide me with a tutorial on how threads work and how runnables work too. i fixed the error ut old me about but still when i try to add another thread to my program i got an error saying that, i must decalre the new thread in a seperate file please can u have a look on what i have:
import java.awt.*;
import java.awt.event.*;
import java.text.DateFormat;
import java.util.*;
import javax.swing.*;
import java.sql.*;
import java.net.URL;
import java.io.*;
public class FinalMachine extends JFrame
private JPanel MainPanel, ThicknessPanel, MainManager,fieldsPanel, sub_panel;
private Container c;
private CardLayout CardManager;
private String timezone;
private static final int ONE_SECOND = 1000;
private JLabel welcome_label, label1, label2, label3,field_label;
private JTextField data_entry;
private JPanel thick_figure;
private int num_of_hits, next_index, recCount, read_flag;
private int dataBuffer[];
private FileReader data_file;
private BufferedReader b_data_file;
private File tem_file;
private Connection connection;     
final int num_of_rec = 20;
public FinalMachine()
super("PHOENIX MACHINERY s.a.l");
/* load JDBC drivers */
try {
String url = "jdbc:odbc:DataEntry";
Class.forName( "sun.jdbc.odbc.JdbcOdbcDriver" );
     connection = DriverManager.getConnection( url );
     System.out.println( "Connection Suucessfull");
catch ( ClassNotFoundException cnfex ) {
// process ClassNotFoundExceptions here
cnfex.printStackTrace();
     System.out.println( "Connection UN Suucessfull");
catch ( SQLException sqlex ) {
// process SQLExceptions here
sqlex.printStackTrace();
     System.out.println( "Connection UN Suucessfull");
catch ( Exception ex ) {
// process remaining Exceptions here
ex.printStackTrace();
     System.out.println( "Connection UN Suucessfull");
/* Intializing global values */
dataBuffer = new int[60];
/* Start all threads */
/* Start filling data file in global array */
     loadData dataFile = new loadData();
     dataFile.start();          
     setData setdata = new setData();
     setdata.start();          
/* Adding control to window application */
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent windowevent)
// setDefaultCloseOperation(0);
          System.exit(0);
public void windowDeiconified(WindowEvent eve)
setState(0);
addComponentListener(new ComponentAdapter() {
public void componentResized(ComponentEvent componentevent)
setSize(500, 500);
Dimension dimension1 = Toolkit.getDefaultToolkit().getScreenSize();
if(dimension1.width == 800 && dimension1.height == 600)
setLocation(150, 25);
else
if(dimension1.width == 1024 && dimension1.height == 768)
setLocation(200, 100);
/* Setting the location of the application on the screen */
Dimension dimension = Toolkit.getDefaultToolkit().getScreenSize();
if(dimension.width == 800 && dimension.height == 600)
setLocation(150, 25);
else
if(dimension.width == 1024 && dimension.height == 768)
setLocation(200, 100);
/* Constructing the main menu */
     JMenuBar bar = new JMenuBar();
     setJMenuBar( bar );
     JMenu fileMenu = new JMenu( "File");
     fileMenu.setMnemonic( 'F' );
     JMenuItem mainItem = new JMenuItem( "Main page" );
     mainItem.setMnemonic( 'M' );
     mainItem.addActionListener (
          new ActionListener() {
               public void actionPerformed( ActionEvent e )
               CardManager.show(MainManager, "main");
     fileMenu.add( mainItem );
     JMenuItem dataItem = new JMenuItem( "Database page" );
     dataItem.setMnemonic( 'D' );
     dataItem.addActionListener (
          new ActionListener() {
               public void actionPerformed( ActionEvent e )
               CardManager.show(MainManager, "data_base");
     fileMenu.add( dataItem );
     JMenuItem printItem = new JMenuItem( "Print" );
     printItem.setMnemonic( 'P' );
     printItem.addActionListener (
          new ActionListener() {
               public void actionPerformed( ActionEvent e )
               PrintUtilities.printComponent(MainManager);
     fileMenu.add( printItem );
     JMenuItem exitItem = new JMenuItem( "Exit" );
     exitItem.setMnemonic( 'P' );
     exitItem.addActionListener (
          new ActionListener() {
               public void actionPerformed( ActionEvent e )
                    System.exit(0);
     fileMenu.add( exitItem );
     bar.add( fileMenu );
     JMenu figureMenu = new JMenu( "Figures");
     figureMenu.setMnemonic( 'G' );
     JMenuItem thicknessItem = new JMenuItem( "Thickness" );
     thicknessItem.setMnemonic( 'T' );
     thicknessItem.addActionListener (
          new ActionListener() {
               public void actionPerformed( ActionEvent e )
               CardManager.show(MainManager, "thickness");
     figureMenu.add( thicknessItem );
     bar.add( figureMenu );
     JMenu helpMenu = new JMenu( "Help");
     helpMenu.setMnemonic( 'H' );
     JMenuItem aboutItem = new JMenuItem( "About us" );
     aboutItem.setMnemonic( 'A' );
     aboutItem.addActionListener (
          new ActionListener() {
               public void actionPerformed( ActionEvent e )
               JOptionPane.showMessageDialog(null, "Engineer Bilal Haidar (Computer & "+                     "Communication Engineering)\n\n All Rights Reserevd. @ 2002",
                    "About me...", JOptionPane.PLAIN_MESSAGE);
     helpMenu.add( aboutItem );
     bar.add( helpMenu );
/* Initializing the panels */
c = getContentPane();
c.setLayout(new FlowLayout());
CardManager = new CardLayout();
MainManager = new JPanel(false);
MainManager.setLayout(CardManager);
c.add(MainManager);
javax.swing.border.Border border = BorderFactory.createEmptyBorder(10, 10, 5, 10);
MainPanel = new JPanel(false);
MainPanel.setLayout(new BoxLayout(MainPanel, 1));
MainPanel.setBorder(border);
ThicknessPanel = new JPanel(false);
ThicknessPanel.setLayout(new BoxLayout(ThicknessPanel, 1));
ThicknessPanel.setBorder(border);
fieldsPanel = new JPanel(false);
fieldsPanel.setLayout( new BoxLayout( fieldsPanel,1));
fieldsPanel.setBorder(border);
sub_panel = new JPanel(false);
sub_panel.setLayout( new BoxLayout(sub_panel,0) );
sub_panel.setBorder(border);
thick_figure = new JPanel(false);
thick_figure.setBorder(border);
/* Filling the main panel */
JLabel jlmain = new JLabel("Main Page");
MainPanel.add(jlmain);
timezone = showTime(new Locale("en", "US"));
JLabel jltime = new JLabel(" " + timezone);
MainPanel.add(jltime);
MainManager.add(MainPanel, "main");
/* Filling the thickness panel */
num_of_hits = 0;
next_index = 0;
/* fill in with ero values for everything*/
/*display the figure*/
ThicknessPanel.add(thick_figure);
JLabel blanklabel = new JLabel(" ");
ThicknessPanel.add(blanklabel);
JButton build_fig = new JButton("Draw Figure");
build_fig.addActionListener(
     new ActionListener() {  // anonymous inner class
     public void actionPerformed( ActionEvent e )
if ( num_of_hits == 0 )
/* draw figure based on first 20 points in the array */
next_index = num_of_rec;
else
if ( num_of_hits > 3 )
JOptionPane.showMessageDialog(null,"No more data to draw","Error Drawing",JOptionPane.ERROR_MESSAGE);
else
/* draw the figure starting the data from index 20*/
next_index = next_index + num_of_rec;
num_of_hits += 1;
ThicknessPanel.add(build_fig);
MainManager.add(ThicknessPanel, "thickness");
/* filling the database panel */
label1 = new JLabel(" ",SwingConstants.CENTER);
welcome_label = new JLabel(" Database Page ",SwingConstants.CENTER);
label2 = new JLabel(" ",SwingConstants.CENTER);
fieldsPanel.add( label1 );
fieldsPanel.add( welcome_label );
fieldsPanel.add( label2 );
field_label = new JLabel(" Enter your name: ");
data_entry = new JTextField( 10 );
sub_panel.add( field_label );
sub_panel.add( data_entry );
fieldsPanel.add( sub_panel );
JButton add_data = new JButton( "Add me" );
add_data.addActionListener(
     new ActionListener() {  // anonymous inner class
     public void actionPerformed( ActionEvent e )
          try {
Statement statement = connection.createStatement();
               String get_field;
          get_field = data_entry.getText();
          String query = "INSERT INTO data (anyField) VALUES ('"+get_field+"')";
          int result1 = statement.executeUpdate( query );
          if ( result1 == 1 )
          JOptionPane.showMessageDialog(null, "Thanks for the info..."," Data Entry Success",JOptionPane.INFORMATION_MESSAGE);
                    data_entry.setText(" ");     
          else
                    JOptionPane.showMessageDialog(null, "Sorry, your name was not added...","Data entry error",JOptionPane.ERROR_MESSAGE);
     catch ( SQLException sqlex ) {
     // process SQLExceptions here
          sqlex.printStackTrace();
               System.out.println( "Connection UN Suucessfull");
          catch ( Exception ex ) {
          // process remaining Exceptions here
          ex.printStackTrace();
               System.out.println( "Connection UN Suucessfull");
fieldsPanel.add(add_data);
MainManager.add(fieldsPanel, "data_base");
/* display time */
Timer timer = new Timer(1000, new ActionListener() {
public void actionPerformed(ActionEvent actionevent)
timezone = showTime(new Locale("en", "US"));
setTitle("PHOENIX MACHINERY s.a.l " + timezone);
timer.start();
public static void main(String args[])
FinalMachine finalmachine = new FinalMachine();
finalmachine.setSize(500, 500);
ImageIcon imageicon = new ImageIcon("images/pc.gif");
finalmachine.setIconImage(imageicon.getImage());
finalmachine.show();
public static String showTime(Locale locale)
java.util.Date date = new java.util.Date();
byte byte0 = 2;
DateFormat dateformat = DateFormat.getTimeInstance(byte0, locale);
String s = dateformat.format(date);
return s;
/* Thread loadData starts here */
public class loadData extends Thread
public void run()
try {
          readMyFile();
          read_flag = 1;
          notify();
catch( Exception x )
System.out.println("The following error occured in LoadData thread : "+x.toString() );
} // run() ends here
/* method read file inside thread loadData */
void readMyFile() {
String record = " ";
recCount = 0;
try {
          tem_file = new File("mydata.dat");
          data_file = new FileReader(tem_file);
          b_data_file = new BufferedReader( data_file );
          record = new String();
          while ( (record = b_data_file.readLine()) != null ) {
          dataBuffer[recCount] = Integer.parseInt(record);
          recCount += 1; }
     b_data_file.close();     
          catch (IOException e) {
     System.out.println("Uh oh, got an IOException error!");
     e.printStackTrace();
     } // end of readMyFile()
} // thread loadData ends
public class setData extends Thread {
public void run()
try {
          while ( !read_flag ) {
               try {     wait(); }
               catch( InterruptedException e ) {
                    e.printStackTrace();
          } // end while
          for(int index = 0; index < 60; index++)
          System.out.println("Array["+index+"] = "+dataBuffer[index]);
catch( Exception x )
System.out.println("The following error occured in LoadData thread : "+x.toString() );
} // run() ends here
the only added thing is the setData thread, i want this thread to start printing out the array whenever, loadData thread has finished filling the data inside the array please i need ur help.