AsyncTask not executiong in oncreate

Issue

I'm Working in a project, I'm tring to download images from a folder, I have this code:

private class DownloadTask extends AsyncTask<ArrayList<URL>, Integer, List<Bitmap>> {
    // Before the tasks execution
    protected void onPreExecute() {
        // Display the progress dialog on async task start
        mProgressDialog.show();
        mProgressDialog.setProgress(0);
    }

    // Do the task in background/non UI thread
    protected List<Bitmap> doInBackground(ArrayList<URL>... urls) {
        int count = urls[0].size();
        HttpURLConnection connection = null;
        List<Bitmap> bitmaps = new ArrayList<>();

        // Loop through the urls
        for (int i = 0; i < count; i++) {
            URL currentURL = urls[0].get(i);
            // So download the image from this url
            try {
                // Initialize a new http url connection
                connection = (HttpURLConnection) currentURL.openConnection();

                // Connect the http url connection
                connection.connect();

                // Get the input stream from http url connection
                InputStream inputStream = connection.getInputStream();

                // Initialize a new BufferedInputStream from InputStream
                BufferedInputStream bufferedInputStream = new BufferedInputStream(inputStream);

                // Convert BufferedInputStream to Bitmap object
                Bitmap bmp = BitmapFactory.decodeStream(bufferedInputStream);

                // Add the bitmap to list
                bitmaps.add(bmp);

                // Publish the async task progress
                // Added 1, because index start from 0
                publishProgress((int) (((i + 1) / (float) count) * 100));
                if (isCancelled()) {
                    break;
                }

            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                // Disconnect the http url connection
                connection.disconnect();
            }
        }
        // Return bitmap list
        return bitmaps;
    }

    // On progress update
    protected void onProgressUpdate(Integer... progress) {
        // Update the progress bar
        mProgressDialog.setProgress(progress[0]);
    }

    // On AsyncTask cancelled
    protected void onCancelled() {
        //Snackbar.make(mCLayout,"Task Cancelled.",Snackbar.LENGTH_LONG).show();
    }

    // When all async task done
    protected void onPostExecute(List<Bitmap> result) {
        // Hide the progress dialog
        mProgressDialog.dismiss();


        // Loop through the bitmap list
        for (int i = 0; i < result.size(); i++) {

            Bitmap bitmap = result.get(i);
            saveToSdCard(bitmap,arrayID.get(i).toString());
        }
    }
}

// Custom method to convert string to url
protected URL stringToURL(String urlString) {
    try {
        URL url = new URL(urlString);
        return url;
    } catch (MalformedURLException e) {
        e.printStackTrace();
    }
    return null;
}


public static String saveToSdCard(Bitmap bitmap, String filename) {
    String stored = null;
    File sdcard = Environment.getExternalStorageDirectory();
    File folder = new File(sdcard.getAbsoluteFile(), "/imagens");
    folder.mkdir();
    File file = new File(folder.getAbsoluteFile(), filename);

    try {
        FileOutputStream out = new FileOutputStream(file);
        bitmap.compress(Bitmap.CompressFormat.JPEG, 90, out);
        out.flush();
        out.close();
        stored = "success";
    } catch (Exception e) {
        e.printStackTrace();
    }
    return stored;
}

And I start this process using a button click like this:

mButtonDo.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            // Execute the async task

            ArrayList<URL>arrayURL=new ArrayList<URL>();

            for (Integer i:arrayID)
            {
                URL url = stringToURL(getString(R.string.link)+i.toString()+".jpg");
                arrayURL.add(url);
            }

            mMyTask = new DownloadTask().execute(arrayURL);
        }
    });

And it works as I want too. But the problem now is that I want that this process is automatic and do when the Activity is started, so I putted this code in the OnCreate method:

ArrayList<URL>arrayURL=new ArrayList<URL>();

            for (Integer i:arrayID)
            {
                URL url = stringToURL(getString(R.string.link)+i.toString()+".jpg");
                arrayURL.add(url);
            }

            mMyTask = new DownloadTask().execute(arrayURL);

But it won't do anything, with the button click it starts fine, but in the OnCreate method it wont do anything, do anyone know how to solve this issue? Thanks for your help and time.

EDITED And have this code to fill my arrayID:

 public void BuscarIdProduto_Imagens()
{
    new Thread(new Runnable() {
        public void run() {

            String SOAP_ACTION = "http://p4.com/BuscarIdProdutos";
            String METHOD_NAME = "BuscarIdProdutos";


            //Criar um Pedido SOAP
            SoapObject request = new SoapObject(NAMESPACE, METHOD_NAME);

            //Parametrização do SOAP
            SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(SoapEnvelope.VER11);


            //O envelope SOAP que se associa ao pedido
            envelope.setOutputSoapObject(request);

            //Classe: Indicar como o Servidor de WS pode ser alcançado
            HttpTransportSE androidHttpTransport = new HttpTransportSE(URL);

            try{
                //SOAP Request(Pedido)
                androidHttpTransport.call(SOAP_ACTION, envelope);


                //IR buscar a Resposta que me foi enviado pelo Servidor de WS
                SoapObject response = (SoapObject) envelope.bodyIn;

                if (response.getPropertyCount() > 0) {

                    for (int i = 0; i < response.getPropertyCount(); i++) {

                        SoapPrimitive soapObject = ((SoapPrimitive) response.getProperty(i));
                        //instanciar    o   canal   de  output

                        arrayID.add(Integer.valueOf(soapObject.toString()));
                    }
                }

                System.out.println();
            } catch (Exception ex) {
                System.out.println("------------------------------>" + ex.toString());
            }

        }
    }).start();
}

I debuged the program and I think the KSOAP finish with his thread after the AsyncTask starts, and that can not be possivel because I need the array filled, is there some way to start the asynctask after the ksoap thread is finish?

Solution

So from your code snippets I assume that problem is calling both methods in onCreate but both methods do network calls. So basically when you call this part of code:

ArrayList<URL>arrayURL=new ArrayList<URL>();

for (Integer i:arrayID) {
     URL url = stringToURL(getString(R.string.link)+i.toString()+".jpg");
     arrayURL.add(url);
   }

mMyTask = new DownloadTask().execute(arrayURL);

In this case arrayID didn't get values yet and probably for loop is skipped and an empty list or arrayURL is passed to the AsyncTask. That will also answer why code works on onClick because meanwhile arrayID is populated with data from network.

So what you want is to make sure that arrayID is populated with data before you call part of code which I pasted above. So create an interface inside your Activity for example:

 public interface OnDataFetched {
   void fetchSuccess(ArrayList<URL> arrayID);
 }

Now go to your Activity and implement this interface and override method fetchSuccess:

public class YourAcitivity extends AppCompatActivity implements OnDataFetched
...

@Override
public void fetchSuccess(ArrayList<URL> arrayID) {

}

After that in same Activity create a field:

private OnDataFetched onDataFetched;

Inside onCreate:

onDataFetched = this;

After that go into your BuscarIdProduto_Imagens method after for loop:

if (response.getPropertyCount() > 0) {

                for (int i = 0; i < response.getPropertyCount(); i++) {

                    SoapPrimitive soapObject = ((SoapPrimitive) response.getProperty(i));
                    //instanciar    o   canal   de  output

                    arrayID.add(Integer.valueOf(soapObject.toString()));
                }
             if(onDataFetched != null)
                onDataFetched.fetchSuccess(arrayID);
     }

And the last thing move AsyncTask code inside ovirrieded fetchSuccess:

@Override
public void fetchSuccess(ArrayList<URL> arrayID) {
for (Integer i:arrayID) {
     URL url = stringToURL(getString(R.string.link)+i.toString()+".jpg");
     arrayURL.add(url);
    }
    mMyTask = new DownloadTask().execute(arrayURL);
   }

Answered By - Yupi