NetworkOnMainThread error still

Question

I am experimenting with firebase and want to read a textfile from the bucket. I can copy the file to local disk, which works fine. Now I want to read the textfile and copy the contents to an arraylist. This time I get the NetworkOnMainThread although I start a new thread to do the work. At least I think I am.I read about using Asynchtask, but would like to know WHY this is not working as expected. The code to get the InputstreamfromURL worked fine in the past.

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_download);
    downloadtext = (TextView) findViewById(R.id.downloadtext);
    text = new ArrayList<>();
    listViewText = (ListView) findViewById(R.id.listViewtext);
    listViewText.setAdapter(new ArrayAdapter(getApplicationContext(), android.R.layout.simple_list_item_1, text));

    Thread thread= new Thread(){
        public void run() {
            storage = FirebaseStorage.getInstance();
            storageRef = storage.getReferenceFromUrl("gs://fir-test-68815.appspot.com");
            filename = "testfile.txt";
            StorageReference file = storageRef.child(filename);

            file.getDownloadUrl().addOnSuccessListener(new OnSuccessListener<Uri>() {
                @Override
                public void onSuccess(Uri uri) {
                    Log.d(MainActivity.TAG, "URL =" + uri.toString());
                    try {
                        InputStream is = getInputStreamFromURL(uri);
                        text = getText(is);
                        textReady.post(new Runnable() {
                            @Override
                            public void run() {
                                ((ArrayAdapter)listViewText.getAdapter()).notifyDataSetChanged();
                            }
                        });
                    } catch (IOException e) {
                        e.printStackTrace();
                    }

                }
            });


        }
        private ArrayList<String> getText(InputStream is) throws IOException {
            ArrayList<String> text = new ArrayList<>();
            BufferedReader reader = null;
            reader = new BufferedReader(new InputStreamReader(is, "UTF-8"));
            String line;
            while ((line = reader.readLine()) != null) {
                text.add(line);
            }
            return text;
        }

        private InputStream getInputStreamFromURL(Uri urlToGet) throws IOException {
            InputStream is = null;
            URL downloadURL = new URL(urlToGet.toString());
            HttpURLConnection conn = (HttpURLConnection) downloadURL.openConnection();
            conn.setReadTimeout(10000 /* milliseconds */);
            conn.setConnectTimeout(15000 /* milliseconds */);
            conn.setRequestMethod("GET");
            conn.setDoInput(true);
            // Starts the query
            conn.connect();
// next two lines produce the error
            int response = conn.getResponseCode();
            is = conn.getInputStream();
            return is;
        }
    };
    thread.start();
    textReady = new Handler();

}

Make a Service responsible for this – Jan Oct 16 '16 at 10:39 — Jan, Oct 16 '16 at 10:39
Will do. Just try to understand firebase for now – KvdLingen Oct 16 '16 at 13:12 — KvdLingen, Oct 16 '16 at 13:12

score 1 · Accepted Answer · answered Oct 16 '16 at 11:08

Firebase event callbacks are by default invoked on the main UI thread. That also happens with your OnSuccessListener.

There are also other ways to download files with Firebase. But if you still want to use getDownloadUrl(), you'll need to implement the downloading on a separate thread (for example using AsyncTask) after getDownloadUrl() callback fires.

NetworkOnMainThread error still

1 Answers1