How can I repaint part of screen on blackberry while connections run? - multithreading

Question

I have two questions.
The first is about updating the UI, the second is when I try to connect to the camera to get a mjpeg stream and run getResponseCode(), the app locks there. The MDS shows a lot of data transferring.
I have some classes like ....:
Http extends Thread {
public abstract String getUrl();
public abstract String getBase64Encode();
public abstract void onReturn(int responseCode, InputStream is,int lenght);
protected abstract void onError(Exception e);
}
CameraHttp extends Http and MjpegHttp extends CameraHttp.
http connects to a URL which is the jpeg or mjpeg camera adresses.
I have a Camera Class. It starts a connection with the overridden method mjpegconnection.go();
I also have a static bitmap on ViewCam screen which extends MainScreen.
After it starts:
url = getUrl();
queryString = encodeURL(queryString);
byte postmsg[] = queryString.getBytes("UTF-8");
httpConnection = (HttpConnection) Connector.open(url
+ ";deviceside=false", Connector.READ_WRITE);
httpConnection.setRequestMethod(HttpConnection.GET);
httpConnection.setRequestProperty("Authorization", getBase64Encode());
os = httpConnection.openDataOutputStream();
for (int i = 0; i < postmsg.length; i++) {
os.write(postmsg[i]);
}
{
if (!cancel) {
System.out.println(httpConnection.getURL()+
" *****"+httpConnection.getPort());
System.out.println("onreturn oncesi"
+ httpConnection.getResponseCode());
onReturn(httpConnection.getResponseCode(), httpConnection
.openInputStream(),(int) httpConnection.getLength());
System.out.println("onreturn sornrası");
}
os.close();
httpConnection.close();
}
} catch (Exception e) {
System.out.println("hata " + e.getMessage());
try {
httpConnection.close();
Thread.sleep(60);
} catch (Exception ie) {
}
onError(e);
}
After dosomething
// decides mjpeg-jpeg stream
// if it is mjpeg, direct to parser,
// else it sets image with setImage() and return to connection with go();
public void parse(InputStream is, int lenght) {
try {
if (!type.isMjpegStream()) {
setImage(is, lenght);
System.gc();
StaticVar.ActiveCam.setConnected(true);
} else {
if (parser == null) {
parser = new JpegParser(is, this);
} else {
parser.setInputSteam(is, this);
}
parser.parse();
is.close();
}
} catch (Exception e) {
}
}
and
public void setImage(InputStream is, int lenght) {
byte[] raw = new byte[lenght];
try {
is.read(raw);
currentImage = Bitmap.createBitmapFromBytes(raw, 0, raw.length, 1);
ViewCam.ViewCam=currentImage; //static var.
} catch (IOException e) {
System.out.println("catche***********");
// TODO Auto-generated catch block
e.printStackTrace();
}
}
How can I repaint the screen to show the bitmap?
And my ViewCam
public class ViewCam extends MainScreen {
Header header;
String headerString;
public static Bitmap ViewCam;// cam image shows
private static Thread My;// runs connection
void OnStart() {
My = new Thread() {
public void run() {
System.out.println("ONSTART");
StaticVar.ActiveCam.go();
};
};
My.start();
Bitmap bitmap = Bitmap.getBitmapResource("res/main.png");
Bitmap bmp2 = ResizeImage.resizeBitmap(bitmap, Display.getWidth(),
Display.getHeight());
Background bg = BackgroundFactory.createBitmapBackground(bmp2);
this.setBackground(bg);
this.getMainManager().setBackground(bg);
}
public ViewCam() {
StaticVar.ActiveCam.getIp();
OnStart();
headerString ="Cam View";
header = new Header("res/bartop.png", headerString, 0);
add(header);
ViewCam = Bitmap.getBitmapResource("res/spexco_splash.png");
ViewCam = ResizeImage.bestFit(ViewCam, Display.getWidth(), Display
.getHeight());
BitmapField bf = new BitmapField(ViewCam);
add(bf);
}
}

Answer 1

Try Screen.invalidate()
public void invalidate(int x, int y, int width, int height)
Invalidates a region of this screen.
This method marks a region of this screen as needing a repaint. The repainting is handled later by the main event dispatch thread.
Note: Any thread can safely invoke this method, and does not require to synchronize on the event lock.
Overrides:
invalidate in class Manager
Parameters:
x - Left edge of the region in ContentRect coordinates.
y - Top edge of the region in ContentRect coordinates.
width - Width (in pixels) of the region.
height - Height (in pixels) of the region.