private boolean installFromAssets(String sourceFilename, File modelRoot,
      File destinationFile) throws IOException {
    String extension = sourceFilename.substring(sourceFilename.lastIndexOf('.'), 
        sourceFilename.length());
    try {
      if (extension.equals(".zip")) {
        return installZipFromAssets(sourceFilename, modelRoot, destinationFile);
      } else {
        throw new IllegalArgumentException("Extension " + extension
            + " is unsupported.");
      }
    } catch (FileNotFoundException e) {
      Log.d(TAG, "Language not packaged in application assets.");
    }
    return false;
  }
Install a file from application assets to device external storage.

@param sourceFilename
         File in assets to install
@param modelRoot
         Directory on SD card to install the file to
@param destinationFile
         File name for destination, excluding path
@return True if installZipFromAssets returns true
@throws IOException
OCRTest/src/main/java/edu/sfsu/cs/orange/ocr/OcrInitAsyncTask.java