public ByteBuffer run(Retriever retriever) {
      if (!retriever.getState().equals(Retriever.RETRIEVER_STATE_SUCCESSFUL)) return null;

      HTTPRetriever htr = (HTTPRetriever) retriever;
      if (htr.getResponseCode() == HttpURLConnection.HTTP_NO_CONTENT) {
        // Mark tile as missing to avoid excessive attempts
        MercatorTiledImageLayer.this.levels.markResourceAbsent(tile);
        return null;
      }

      if (htr.getResponseCode() != HttpURLConnection.HTTP_OK) return null;

      URLRetriever r = (URLRetriever) retriever;
      ByteBuffer buffer = r.getBuffer();

      String suffix = WWIO.makeSuffixForMimeType(htr.getContentType());
      if (suffix == null) {
        return null; // TODO: log error
      }

      String path = tile.getPath().substring(0, tile.getPath().lastIndexOf("."));
      path += suffix;

      final File outFile = WorldWind.getDataFileStore().newFile(path);
      if (outFile == null) return null;

      try {
        WWIO.saveBuffer(buffer, outFile);
        return buffer;
      } catch (IOException e) {
        e.printStackTrace(); // TODO: log error
        return null;
      }
    }
  protected static String buildLocationPath(String property, String append, String wwDir) {
    String path = propertyToPath(property);

    if (append != null && append.length() != 0) path = WWIO.appendPathPart(path, append.trim());

    if (wwDir != null && wwDir.length() != 0) path = WWIO.appendPathPart(path, wwDir.trim());

    return path;
  }
  protected static String normalizeFileStoreName(String fileName) {
    // Convert all file separators to forward slashes, and strip any leading or trailing file
    // separators
    // from the path.
    String normalizedName = fileName.replaceAll("\\\\", "/");
    normalizedName = WWIO.stripLeadingSeparator(normalizedName);
    normalizedName = WWIO.stripTrailingSeparator(normalizedName);

    return normalizedName;
  }
 protected void saveBuffer(java.nio.ByteBuffer buffer, java.io.File outFile)
     throws java.io.IOException {
   synchronized (this.fileLock) // sychronized with read of file in RequestTask.run()
   {
     WWIO.saveBuffer(buffer, outFile);
   }
 }
  protected boolean loadTile(Tile tile, java.net.URL url) {
    if (WWIO.isFileOutOfDate(url, this.placeNameServiceSet.getExpiryTime())) {
      // The file has expired. Delete it then request download of newer.
      this.getDataFileStore().removeFile(url);
      String message = Logging.getMessage("generic.DataFileExpired", url);
      Logging.logger().fine(message);
      return false;
    }

    PlaceNameChunk tileData;
    synchronized (this.fileLock) {
      tileData = readTileData(tile, url);
    }

    if (tileData == null) {
      // Assume that something's wrong with the file and delete it.
      this.getDataFileStore().removeFile(url);
      tile.getPlaceNameService()
          .markResourceAbsent(tile.getPlaceNameService().getTileNumber(tile.row, tile.column));
      String message = Logging.getMessage("generic.DeletedCorruptDataFile", url);
      Logging.logger().fine(message);
      return false;
    }

    tile.setDataChunk(tileData);
    WorldWind.getMemoryCache(Tile.class.getName()).add(tile.getFileCachePath(), tile);
    return true;
  }
    @Override
    protected ByteBuffer handleXMLContent() throws IOException {
      // Check for an exception report
      String s = WWIO.byteBufferToString(this.getRetriever().getBuffer(), 1024, null);
      if (s.contains("<ExceptionReport>")) {
        // TODO: Parse the xml and include only the message text in the log message.

        StringBuilder sb = new StringBuilder(this.getRetriever().getName());

        sb.append("\n");
        sb.append(WWIO.byteBufferToString(this.getRetriever().getBuffer(), 2048, null));
        Logging.logger().warning(sb.toString());

        return null;
      }

      this.saveBuffer();

      return this.getRetriever().getBuffer();
    }
  private BufferedImage requestImage(MercatorTextureTile tile, String mimeType)
      throws URISyntaxException {
    String pathBase = tile.getPath().substring(0, tile.getPath().lastIndexOf("."));
    String suffix = WWIO.makeSuffixForMimeType(mimeType);
    String path = pathBase + suffix;
    URL url = WorldWind.getDataFileStore().findFile(path, false);

    if (url == null) // image is not local
    return null;

    if (WWIO.isFileOutOfDate(url, tile.getLevel().getExpiryTime())) {
      // The file has expired. Delete it.
      WorldWind.getDataFileStore().removeFile(url);
      String message = Logging.getMessage("generic.DataFileExpired", url);
      Logging.logger().fine(message);
    } else {
      try {
        File imageFile = new File(url.toURI());
        BufferedImage image = ImageIO.read(imageFile);
        if (image == null) {
          String message = Logging.getMessage("generic.ImageReadFailed", imageFile);
          throw new RuntimeException(message);
        }

        this.levels.unmarkResourceAbsent(tile);
        return image;
      } catch (IOException e) {
        // Assume that something's wrong with the file and delete it.
        gov.nasa.worldwind.WorldWind.getDataFileStore().removeFile(url);
        this.levels.markResourceAbsent(tile);
        String message = Logging.getMessage("generic.DeletedCorruptDataFile", url);
        Logging.logger().info(message);
      }
    }

    return null;
  }