blackberry sample app stops downloading

Yes, OSM tile server is not really meant or suitable for commercial services. It has been unstable, it can be down for couple of days. See also http://wiki.openstreetmap.org/wiki/Tile_usage_policy

The issue here is that library uses HTTPConnection, not StreamConnection. If you want to use StreamConnection, then it probably needs not only new ConnectionOpener, but it could need to rewrite other parts of downloader, and currently there is no public API for it.

However, for modified DefaultDownloadStreamOpener.java you can use existing one as template, maybe some basic changes here would work for you:

import java.io.DataInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Enumeration;
import java.util.Hashtable;

import javax.microedition.io.Connector;
import javax.microedition.io.HttpConnection;

import com.nutiteq.log.Log;
import com.nutiteq.utils.IOUtils;

/**
 * Default stream opener used inside library. Handles cleanup for resources
 * opened by it.
 * 
 * Status codes 200 (OK) and 304 (not modified) are handled the same way - with
 * data read.
 * 
 * This implementation tries to follow up to 3 redirects (HTTP status codes 301,
 * 302, 307). If it is not successful, then an error notification will be sent
 * to stream waiter.
 */
public class DefaultDownloadStreamOpener implements DownloadStreamOpener {
  private static final String HTTP_REDIRECT_LOCATION_HEADER = "Location";
  private final String urlExtension;
  private final Hashtable properties = new Hashtable();
  private static final int MAX_FOLLOWED_REDIRECTS = 3;

  /**
   * @param urlExtension
   *          Optional extension for http URLs, for instance ";deviceside=true".
   *          Used on some Blackberry devices.
   */
  public DefaultDownloadStreamOpener(final String urlExtension) {
    this.urlExtension = urlExtension;
  }

  public DefaultDownloadStreamOpener() {
    urlExtension = "";
  }

  /**
   * Add request properties, that will be added added to every request (for
   * example User-Agent).
   * 
   * @param propertyName
   *          request property name
   * @param propertyValue
   *          request property value
   */
  public void addRequestProperty(final String propertyName, final String propertyValue) {
    properties.put(propertyName, propertyValue);
  }

  public void openInputStream(final DownloadStreamWaiter streamWaiter, final String url) {
    openInputStream(streamWaiter, url, 0, null);
  }

  public void openInputStream(final DownloadStreamWaiter streamWaiter,
      final DataPostingDownloadable postingDownloadable) {
    openInputStream(streamWaiter, postingDownloadable.getUrl(), 0, postingDownloadable);
  }

  private void openInputStream(final DownloadStreamWaiter streamWaiter, final String url,
      final int redirects, final DataPostingDownloadable downloadable) {
    final String downloadableUrl = url + urlExtension;
    final DataInputStream dis = null;
    HttpConnection connection = null;
    InputStream is = null;
    String redirectUrl = null;
    try {
      final long startTime = System.currentTimeMillis();
      Log.info("Downloading " + downloadableUrl);
      connection = (HttpConnection) Connector.open(downloadableUrl, Connector.READ_WRITE, true);
      connection.setRequestMethod(HttpConnection.GET);
      connection.setRequestProperty("Cache-Control", "No-Transform");
      if (properties.size() > 0) {
        final Enumeration keysEnum = properties.keys();
        while (keysEnum.hasMoreElements()) {
          final String key = (String) keysEnum.nextElement();
          final String value = (String) properties.get(key);
          connection.setRequestProperty(key, value);
        }
      }

      if (downloadable != null) {
        final byte[] dataBytes = downloadable.getPostContent().getBytes("iso-8859-1");
        connection.setRequestProperty("Content-Length", Integer.toString(dataBytes.length));
        connection.setRequestProperty("content-type", downloadable.getContentType());
        final OutputStream dos = connection.openOutputStream();
        dos.write(dataBytes);
      }

      is = connection.openInputStream();
      final int responseCode = connection.getResponseCode();
      Log.debug("Connection opened in " + (System.currentTimeMillis() - startTime));
      if (responseCode == HttpConnection.HTTP_OK
          || responseCode == HttpConnection.HTTP_NOT_MODIFIED) {
        final long processStart = System.currentTimeMillis();
        streamWaiter.streamOpened(is);
        Log.debug("Response read in " + (System.currentTimeMillis() - processStart));
      } else if (responseCode == HttpConnection.HTTP_TEMP_REDIRECT
          || responseCode == HttpConnection.HTTP_MOVED_PERM
          || responseCode == HttpConnection.HTTP_MOVED_TEMP) {
        redirectUrl = connection.getHeaderField(HTTP_REDIRECT_LOCATION_HEADER);
        Log.debug("Redirect to " + redirectUrl);
      } else {
        streamWaiter.error(RESPONCE_NOT_OK, "");
      }
    } catch (final IOException e) {
      Log.error("Downloader: " + e.getMessage());
      streamWaiter.error(NETWORK_ERROR, e.getMessage());
    } catch (final SecurityException e) {
      Log.error("Downloader security: " + e.getMessage());
      streamWaiter.error(SECURITY_EXCEPTION, e.getMessage());
    } finally {
      IOUtils.closeStream(dis);
      IOUtils.closeStream(is);
      IOUtils.closeConnection(connection);
    }

    if (redirects == MAX_FOLLOWED_REDIRECTS && redirectUrl != null) {
      streamWaiter.error(TOO_MANY_REDIRECTS, "Too manu redirects created!");
      return;
    }

    if (redirectUrl != null) {
      openInputStream(streamWaiter, redirectUrl, redirects + 1, downloadable);
    }
  }
}