How to use AsyncTask class to update the progress of copying a file another directory?

Issue

How should I be using AsyncTask class coupled with a progress bar to perform the copying process of a file to another directory in the local context of the phone sdcard? I have seen a similar example [here][1], but I have no idea how to incorporate the differences/modify the context of the code to suit my context to make it work?

Solution

It would be something like

// Params are input and output files, progress in Long size of 
// data transferred, Result is Boolean success.
public class MyTask extends AsyncTask<File,Long,Boolean> {
   ProgressDialog progress; 

  @Override
  protected void onPreExecute() {
    progress = ProgressDialog.show(ctx,"","Loading...",true);
  }

  @Override
  protected Boolean doInBackground(File... files) {
    copyFiles(files[0],files[1]);
    return true;
  }

  @Override
  protected void onPostExecute(Boolean success) {
    progress.dismiss();
    // Show dialog with result
  }

  @Override
  protected void onProgressUpdate(Long... values) {
    progress.setMessage("Transferred " + values[0] + " bytes");
  }
}

Now, inside copyFiles you will have to call publishProgress() with size of data transferred, for example. Note that progress generic parameter is Long. You can use CountingInputStream wrapper from commons-io for that.

There are number of additional things top take care of, but in the nutshell that is it.

To start:

  MyTask task = new MyTask();
  task.execute(src,dest);

Answered By - Alex Gitelman