Can any one tell what is the problem in this code?

Question

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.awt.geom.*;
import java.util.*;
public class AppletTest2 extends JApplet implements ActionListener,MouseMotionListener,WindowListener{
JFrame fr = new JFrame("Visual Tool -- Work Flow Editor");
     JPanel panel1 = new JPanel();
     JPanel panel2 = new JPanel();
     JButton sButton = new JButton("Source");
     JButton rButton = new JButton("Redirection");
     JButton dButton = new JButton("Destination");
     JButton connect = new JButton("Connect");
     BasicStroke stroke = new BasicStroke(2.0f);
     int flag = 1 ;
     Vector lines = new Vector();
     JButton sBut,rBut,dBut;
int x1 = 0 ;
     int y1 = 0 ;
     int x2 = 0 ;
     int y2 = 0;
     int x3 = 0;
     int y3 = 0;
     int i=0;
     int j=0;
     int k=0;
     int l = 100;
int b = 50;
public void init(){
          /*********Frame ******************/
fr.getContentPane().setLayout(new BorderLayout());
     fr.setSize(700,500);
          fr.getContentPane().add(panel1,BorderLayout.CENTER);
          fr.getContentPane().add(panel2,BorderLayout.SOUTH);
          fr.addWindowListener(this);
          /*****************PANEL 1*********************/
          panel1.setLayout(null);
panel1.setBounds(new Rectangle(0,0,400,400));
          panel1.setBackground(new Color(105,105,205));
/************************PANEL 2 *************/
          panel2.setLayout(new FlowLayout());
          panel2.setBackground(new Color(105,205,159));
          panel2.add(sButton);
          panel2.add(rButton);
          panel2.add(dButton);
          panel2.add(connect);
          connect.setToolTipText("Use this button after selecting From and To position to connect");
          /***************************LISTENER********************/
sButton.addActionListener(this);
          rButton.addActionListener(this);
          dButton.addActionListener(this);
          connect.addActionListener(this);
          fr.setVisible(true);     
          fr.setResizable(false);
     } // init clse
/************************** START METHOD **********************************************/
          public void start(){                                 
               System.out.println("inside start");
               paint(panel1.getGraphics());
/*******************************APPLET METHODS **************************************************/
          public void stop(){}
          public void destroy(){}
/******************************MOUSE MOTION LISTENERS METHOD*************************************/
          public void mouseMoved(MouseEvent e){System.out.println("moved");}
          public void mouseDragged(MouseEvent e){System.out.println("dragged");}
/***************************************ACTION EVENT IMPLEMENTAION *******************************/
     public void actionPerformed(ActionEvent e){
          if (e.getSource().equals(sButton)){          
          sourceObject("Source Object");          
          else if (e.getSource().equals(rButton)){          
          redirectionObject("Redirection");
          i = i+1;
          else if (e.getSource().equals(dButton)){
          destinationObject("Destination");
               j= j+1;
          else if (e.getSource().equals(connect)){
               System.out.println("am inside connect");                
               paint(panel1.getGraphics());               
else if(e.getSource().equals(sBut)){
               System.out.println("am s button");                
               x1 = sBut.getX() + l;
               y1 = sBut.getY() + (b/2);
          else if(e.getSource().equals(rBut)){
               System.out.println("am r button");               
               x2 = rBut.getX() ;
               y2 = rBut.getY()+ b/2;
               System.out.println("x2 : " + x2 + "y2 :" +y2 );
          else if(e.getSource().equals(dBut)){
               System.out.println("am d button");                
               x3 = dBut.getX();
y3 = dBut.getY()+ b/2;
} // action close
/**********************Main **********************************/     
     public static void main(String args[]){
     JApplet at = new AppletTest2();
          at.init();
          at.start();
/********************my methods starts here *******************/
     public void sourceObject(String name){     
sBut = new JButton(name);
     panel1.add(sBut);
     sBut.setBounds(new Rectangle(20,208,l,b));     
     sBut.addActionListener(this);
System.out.println("am inside the source object") ;
     public void redirectionObject(String name){     
     rBut = new JButton(name);
     panel1.add(rBut);
     rBut.setBounds(new Rectangle(290,208,l,b));     
rBut.addActionListener(this);
System.out.println("am inside the redirection :" + j) ;
public void destinationObject(String name){     
     dBut = new JButton(name);
     panel1.add(dBut);     
System.out.println("am inside the destination object") ;
if (j == 0)
               dBut.setBounds(new Rectangle(566,60,l,b));                    
               System.out.println("am inside the destination:" + j) ;
               } else if (j == 2)
                    dBut.setBounds(new Rectangle(566,208,l,b));     
                    System.out.println("am inside the destination :" + j) ;
               } else if (j == 1)
dBut.setBounds(new Rectangle(566,350,l,b));     
                    System.out.println("am inside the destination :" + j) ;
dBut.addActionListener(this);
/* public void connectObject(Object obj1,Object obj2){
System.out.println("nothing");
/************************************* PAINT **************************/
public void paint(Graphics g){
     System.out.println("inside paint");
     Graphics2D g2 = (Graphics2D) g;
     g2.setStroke(stroke);
if(flag == 1){
System.out.println("inside flag");
int np = lines.size();
                    System.out.println(np);
                         for (int I=0; I < np; I++) {                       
     Rectangle p = (Rectangle)lines.elementAt(I);
                         System.out.println("width" + p.width);
                         g2.setColor(Color.red);
                         g2.drawLine(p.x,p.y,p.width,p.height);
                         System.out.println(p.x +"" +""+ p.y + ""+ ""+ p.width+ "" + ""+ p.height);
flag = -1;
}else if(flag == -1){
     if(x1 != 0 && y1 != 0 && x2 != 0 && y2 != 0 ){
// Graphics2D g2 = (Graphics2D) g;
     // g2.setStroke(stroke);
g2.setColor(Color.red);
     g2.drawLine(x1,y1,x2,y2);
     lines.addElement(new Rectangle(x1,y1,x2,y2));     
     x1 = 0 ;y1 = 0 ;
     x2 = 0 ;y2 = 0 ;
//     g2.drawLine(100,100,200,200);
else if (x2 != 0 && y2 != 0 && x3 != 0 && y3 != 0 )
          // Graphics2D g2 = (Graphics2D) g;
               // g2.setStroke(stroke);
          g2.setColor(Color.green);
                    g2.drawLine(x2,y2,x3,y3);
                    lines.addElement(new Rectangle(x2,y2,x3,y3));
                    x2 = 0; y2 = 0 ;
                    x3 = 0 ; y3 = 0 ;                    
else if (x1 != 0 && y1 != 0 && x3 != 0 && y3 != 0)
               //     Graphics2D g2 = (Graphics2D) g;
               // g2.setStroke(stroke);
               g2.setColor(Color.red);
               g2.drawLine(x1,y1,x3,y3);
                    lines.addElement(new Rectangle(x1,y1,x3,y3));                              
                    x1 = 0; y1 = 0 ;
                    x3 = 0 ; y3 = 0 ;                    
// repaint();
/********************************WINDOW LISTENER IMPLEMENTATION *****************************/
public void windowActivated(WindowEvent we) { 
          flag = 1;
          paint(panel1.getGraphics());
System.out.println("windowActivated -- event 1");
     //start();               
     public void windowClosed(WindowEvent we) {
                                                            System.out.println("windowClosed -- 2");
     public void windowClosing(WindowEvent we){
                                                            System.out.println("windowClosing -- 3");
public void windowDeactivated(WindowEvent we) {
                                                                 System.out.println("windowDeactivated -- 4");
public void windowDeiconified(WindowEvent we) {
                                                                 flag = 1;
                                                                 System.out.println("windowDeiconified -- 5");          
                                                                 paint(panel1.getGraphics());           
public void windowIconified(WindowEvent we) {           
                                                       System.out.println("windowIconified -- 6");
                                                       //paint(panel1.getGraphics());
public void windowOpened(WindowEvent we) {             
                                                  //     flag = 1;
                                                  //     paint(panel1.getGraphics());
                                                       System.out.println("windowopened -- 7");     
The problem am facing here is that when i minimize the frame and maximize , my old lines are getting disappared.
For avoiding that i am storing the old coordinates and
try to redraw , when maximize.
but the lines are coming for flash of second and disappearing once again ?
can any one help?
thanks all

Answer 1

Very interestingly the same code is repainting in
Linux SUSE,jdk1.3.
but not in WINNT , jdk 1.3
Any reason ?
Is the swing 100 % platform independenet ?????
Does swing also uses native thread ???