public void add(int what,DownloadRequest downloadRequest,DownloadListener downloadListener){
  if (downloadRequest.inQueue())   Logger.w("This request has been in the queue");
 else {
    downloadRequest.setQueue(mUnFinishQueue);
    downloadRequest.onPreResponse(what,downloadListener);
    downloadRequest.setSequence(mInteger.incrementAndGet());
    mUnFinishQueue.add(downloadRequest);
    mDownloadQueue.add(downloadRequest);
  }
}

public void add ( int what , DownloadRequest downloadRequest , DownloadListener downloadListener ) { if ( downloadRequest . inQueue ( ) ) Logger . w ( "This request has been in the queue" ) ; else { downloadRequest . setQueue ( mUnFinishQueue ) ; downloadRequest . onPreResponse ( what , downloadListener ) ; downloadRequest . setSequence ( mInteger . incrementAndGet ( ) ) ; mUnFinishQueue . add ( downloadRequest ) ; mDownloadQueue . add ( downloadRequest ) ; } }
add a download task to download queue , waiting for execution , if there is no task in the queue or the number of tasks is less than the number of thread pool , will be executed immediately .
