android AsyncTask xml parsing

Question

i try to parse a large xml document in a AsyncTask. The FeinstaubActivity starts but i only see a black screen and then get back to the RSSReaderActivity from where i starte

Answer 1

Ah, not sure you can do that: http://developer.android.com/reference/android/os/AsyncTask.html shows that execute returns void.

You want this:

Document document = null;

    protected void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.feinstaub);
       new ParseXMLFile().execute();
    }

    void setDocument(Document document){ this.document = document; }

    private class ParseXMLFile extends AsyncTask<Integer, Integer, Document>{
    @Override public void onPostExecute(Document d){ setDocument(d); }

    @Override
    protected Document doInBackground(Integer... params) {
        Document parsedXML = null;
        try {
            parsedXML = builder.parse(getApplicationContext().getResources().openRawResource(R.raw.finedust));
        } catch (NotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (SAXException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return parsedXML;
    }

}

There's a bit of scoping you need to do: pass the parent activity in or declare the setDocument method appropriately somehow so you can call it back from inside the AsyncTask, but something like that should do it.