Strange behaviour with connection to 3G network

[Utumn0]

Hello J2ME gurus,

I am enclosing an example midlet. If you run it in your phone and click 'test' , the midlet will download (http) Google's front page. Just before the download, the phone will , of course, connect to 3G network (duh!) and a white '3G' icon will appear in the top-left corner.

The problem is that even after the download finishes, the icon does NOT disappear no matter how long one waits (I tried 10 minutes). The icon only disappears when one exits the midlet.

Question: why is that? isn't the phone supposed to automatically disconnect after some time of inactivity, say, 1 min?

AFAIK, there are only 2 possibilities:

1) there is something wrong with the code below ( hopefully ) or
2) if a midlet performs network operation, nokia's phones will stay connected no matter how long you run the midlet and only disconnect when you exit it. ( that would suck )

import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import javax.microedition.io.*;
import java.io.*;

public class TestDownload extends MIDlet implements CommandListener, Runnable
  {
  private Display mDisplay;
  private TextBox mTextBox;
  private Command mTestCommand, mExitCommand;
  private static Thread mNetworkThrd = null;

  private HttpConnection  hc  = null;
  private DataInputStream din = null;

  public TestDownload()
    {
    mTestCommand = new Command("Test", Command.SCREEN, 1);
    mExitCommand = new Command("Exit", Command.EXIT, 1);

    mTextBox = new TextBox("Test", "", 32, TextField.ANY);
    mTextBox.addCommand(mTestCommand);
    mTextBox.addCommand(mExitCommand);
    mTextBox.setCommandListener(this);
    }

  public void startApp()
    {
    mDisplay = Display.getDisplay(this);
    mDisplay.setCurrent(mTextBox);
    }

  public void pauseApp() { }

  public void destroyApp(boolean unconditional) {}

  public void commandAction(Command c, Displayable s)
    {
    if (c == mTestCommand)
      {
      mTextBox.setString("Downloading...");
      mNetworkThrd = new Thread(this);
      mNetworkThrd.start();
      }
    if (c == mExitCommand) notifyDestroyed();
    }

  public void run()
    {
    try
      {
      hc= (HttpConnection)Connector.open("http://www.google.com");
      int length = (int)hc.getLength();
      byte[] data = null;

      if( length != -1 )
        {
        data = new byte[length];
        din = new DataInputStream( hc.openInputStream() );
        din.readFully(data);
        }

      mTextBox.setString("data downloaded, length:"+length);
      }
    catch( IOException ioe )      { mTextBox.setString("IOException"      ); }
    catch( SecurityException se ) { mTextBox.setString("SecurityException"); }
    finally
      {
      try { if( din!=null ) {din.close(); din=null; } }
      catch(IOException ioe) { mTextBox.setString("Exception closing din");}
      try { if(  hc!=null ) { hc.close();  hc=null; } }
      catch(IOException ioe) { mTextBox.setString("Exception closing hc"); }
      }
    }
  } 

[raj_J2ME]

Hi,
That happen on most of the devices.I have read somewhere that the upcoming devices will not behave like that.You are talking about 3G network,even in the case of the GPRS this is the case.And I wonder if that can be get rid of.

[grahamhughes]

There is nothing obviously wrong with the code.

A number of other people have reported the same issue. Certainly, some Nokia devices will disconnect after a brief delay. Possibly, some do not. What model are you using?

Staying connected does no harm, unless you're using full-screen mode, in which case the presence of the "G" icon is annoying.

On some (all?) Series 40s, pressing the END key while the "G" icon is showing will end the connection. (A second press will terminate the application as normal.)

Graham.

[Tiger79]

to shut down the connection on a S60 you can go tho the home (default? screen) by pressing the menu button and the you can press the red button for some time after which the ongoing interent connection will be closed (you will even get an Alert asking you if you're sure if you want to close the connection)...
this is obviously no solution and you cannot expect your users to do such a complex handling, but you might test with it to see if the connection symbol dissapears

[Utumn0]

I have tested with Nokia 3120 and 6220 ( physical devices ) and with a bunch of devices from RemoteDeviceAccess ( N95, E71, 63xx XpressMusic and some others ) - everywhere the same.