Uncaught exception: blocking operation not permitted on event dispatch thread on BlackBerry

I have a HttpConnection thread class. when ı stop httpConnection, I show this messeage. how should ı stop httpConnection??

Blackberry Output Console:

RuntimeException
blocking operation not permitted on event dispatch thread
net_rim_cldc-10
 EventThreadCheck
 throwException
 0x3434
net_rim_cldc_io_tcp
 Protocol
 <private>
 0x18B8
net_rim_cldc_io_tcp
 Protocol
 outputStreamClosed
 0xB2D
net_rim_cldc_io_tcp
 TcpOutputStream
 close
 0x40BF
net_rim_os-2
 ClientProtocol
 close
 0x154E
CepVizyon-2
 Http
 cancel
 0x174F
CepVizyon-2
 Camera
 cancel
 0x6E7
CepVizyon
 ViewCam
 close
 0xE79
net_rim_cldc-7
 Screen
 onClose
 0x5DAC
net_rim_cldc-7
 Screen
 keyCharUnhandled
 0x5C58
net_rim_cldc-9
 MainScreen
 keyCharUnhandled
 0x23D7
net_rim_cldc-7
 Screen
 dispatchKeyEvent
 0x51DB
net_rim_cldc-7
 Screen
 processKeyEvent
 0x718D
net_rim_cldc-7
 UiEngineImpl
 processMessage
 0x9E3C
net_rim_cldc-4
 Application
 processNextMessage
 0x1073
net_rim_cldc-4
 Application
 enterEventDispatcher
 0x775
CepVizyon-2
 CepVizyonMain
 main
 0x1175

parts of My Connection class:

public abstract class Http extends Thread{
    protected HttpConnection httpConnection;
HttpConnectionFactory factory;
protected static Base64 base64;

private boolean cancel = false;
/** bağlantının yapılcağı adres */
protected String url = "";
/** paremetre olarak gönderilecek data */
protected String queryString = "";

    ...

public void cancel() {
        try {
            if (httpConnection != null)
                httpConnection.close();
            if(factory!=null)
                factory.cancel();
        } catch (IOException ex) {
        }
        cancel = true;
    }

part of my screen class:

public void close() {
        super.close();
        Static开发者_StackOverflow社区Var.ActiveCam.cancel();
//      CameraListScreen screen = new CameraListScreen();
//      UiApplication.getUiApplication().pushScreen(screen);
//
    }

and part of Camera Class/*ActiveCam's cancel is here/:

// finishes connection.
    public void cancel() {
        setConnected(false);
        if (mjpeghttp != null) {
            mjpeghttp.cancel();
            //mjpeghttp.interrupt();
            //mjpeghttp = null;

        }
            }

---

It looks like your HttpConnection is accessed from a background (non UI) thread which is good. However your UI calls close() directly which may block. You should consider spawning another thread to do the close().

---

You must work with screen only from event thread

 //safely (recommended)
 Application.getApplication().invokeLater(new Runnable() {
        public void run() {
            //your code here
         }
 });

or

//fast 
synchronized(Application.getEventLock()) {
   //your code here
 }