public boolean downloadFileExists(){
  if (!downloadDirectoryExists())   return false;
  File file=new File(getAbsoluteFilePath());
  return file.exists();
}

public boolean downloadFileExists ( ) { if ( ! downloadDirectoryExists ( ) ) return false ; File file = new File ( getAbsoluteFilePath ( ) ) ; return file . exists ( ) ; }
check whether the file to download already exists
