Help with converting an applet into an application

Question

Here is a set of code which can work perfectly fine as an applet. But I have problem converting it into an application. Any help? I get some null pointer exception. Thanks alot.
//File Name: Radar.java
//Author: Saad Ayub
import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
class Flash extends Thread{
private DrawA dA;
private int x;
private int xCor[];
private int yCor[];
private int i;
private int dir;
private Image im;
private Graphics buff;
public Flash(DrawA dA, Image im, Graphics buff){
this.dA = dA;
this.im = im;
this.buff = buff;
xCor = new int[451];
yCor = new int[451];
dir = 10;
}//end of Flash constructor
public void run(){
for(x = 75, i = 0; x <= 525; x++, i++){
xCor[i] = x - 300;
for(i = 0; i <= 450; i++){
yCor[i] = (int)Math.sqrt(62500 - (xCor[i] * xCor));
yCor[i] = 300 - yCor[i];
for(x = 0; x <= 450; x++){
xCor[x]+=300;
i = 0;
while(true){
try{
Thread.sleep(35);
catch(Exception e){}
dA.repaint();
i += dir;
if(i < 0 || i > 450){
dir = -dir;
i += dir;
}//end of if
}//end of while
}//end of run
public void draw(Graphics g){
int green = 255;
buff.setColor(Color.black);
buff.fillRect(0, 0, 600, 330);
buff.setColor(new Color(0, 70, 0));
buff.fillArc(50, 50, 500, 500, 25, 130);
buff.setColor(Color.green);
if(i > 450)
return;
if(xCor[i] != 0 && yCor[i] != 0)
buff.drawLine(xCor[i], yCor[i], 300, 300);
if(dir > 0){
for(int j = i; j > (i - 100); j--){
if(j >= 0 && j <= 450){
green -= 2;
buff.setColor(new Color(0, green, 0));
buff.drawLine(xCor[j], yCor[j], 300, 300);
}//end of if
}//end of for
}//end of if
else{
for(int j = i; j < (i + 100); j++){
if(j >= 0 && j <= 450){
green -= 2;
buff.setColor(new Color(0, green, 0));
buff.drawLine(xCor[j], yCor[j], 300, 300);
}// end of if
}//end of for
}//end of else
buff.setColor(Color.green);
buff.drawArc(112, 112, 375, 375, 25, 130);
buff.drawArc(174, 174, 250, 250, 25, 130);
buff.drawArc(238, 238, 125, 125, 25, 130);
buff.drawLine(300, 300, 300, 50);
g.drawImage(im, 0, 0, null);
}//end of draw
}//end of flash class
class DrawA extends Panel{
private Flash fl;
private Image im;
private Graphics buff;
public DrawA(Image im){
this.im = im;
buff = im.getGraphics();
fl = new Flash(this, im, buff);
fl.start();
// setBackground(Color.black);
public void paint(Graphics g){
fl.draw(g);
public void update(Graphics g){
paint(g);
public class Radar extends Applet{
public DrawA dA;
private JLabel display;
public Radar()
display = new JLabel("display");
public void init(){
dA = new DrawA(createImage(600, 330));
setLayout(new BorderLayout());
add(dA, BorderLayout.CENTER);
add(display, BorderLayout.EAST);
public void stop(){
destroy();
Edited by: bozovilla on Oct 20, 2008 8:32 AM

Answer 1

Start out by letting this thread die out...
and repost saying that you forgot to use code tags and describe sufficiently what your problem is--things like the actual error message and where it happens.