Problem with "transparent" progress bar

Question

i am trying to implement a progress bar that monitors a long task. I used the example codes given in the swing tutorial and modified a little to make the progress bar indeterminate.
However, when the progress bar pops up, it is transparent, except for its title! I have search the forum and tried all the solutions given for this similar problem. My codes are already threaded.
Here's the excerpt of my codes. I used the LongTask, SwingWorker from the Swing tutorial and adapted ProgressBarDemo to ProgressBarA (only difference is indeterminate).
uploadData();
public boolean uploadData() {
boolean uploadSuccess = false;
final SomeLongTask someLongTask = new SomeLongTask(dataLoader);
final Thread pBarThread = new Thread(new Runnable() {
public void run() {
JFrame pBar = new ProgressBarA(someLongTask);
pBarThread.setPriority(Thread.MAX_PRIORITY);
pBarThread.start();
// this loop hopes to serve as a blocking,
// which apparently did not help.
while (!someLongTask.done()) {
pBarThread.join();
System.out.println("main thread yields and sleeps ");
Thread.yield();
Thread.sleep(1000);
uploadSuccess = someLongTask.getSuccess();
// some more post processing here.
return uploadSuccess;
class SomeLongTask extends LongTask {
DataLoader loader;
boolean success;
boolean completed;
public SomeLongTask(DataLoader l) {
loader = l;
lengthOfTask = 1000;
indeterminate = true;
public Object actualTask() {
statMessage = "Loading...";
success = loader.upload();
stop();
// return value is not important here.
// Just return any dummy value.
return new String("ok");
public boolean getSuccess() {
return success;
I suspect that after the pBarThread started, the main thread proceeds so fast that the progressBar frame cannot show up properly. But i am not very sure on on to thread the post processing part that should wait for the someLongTask to finish. The blocking loop did not seem to help either. :(
Pls kindly advise.
Regards,
kaikit

Answer 1

have you tried resetting ipod, cause as far as i know, this is sometimes just a temporary glitch, mine does this.