CODEWITHSUNDEEP
androidandroid-annotationsnetworkonmainthread
Héctor
Héctor

Reputation: 26034

NetworkOnMainThreadException in AndroidAnnotations

I have a class annotated with @Rest and I use its methods in another with an instance of this, annotated with @RestService. When I call some method of the Rest client class, NetworkOnMainThreadException error appears. I thought that AndroidAnnotations managed the threading in these cases.

Upvotes: 1

Views: 584

Answers (3)

WonderCsabo
WonderCsabo

Reputation: 12207

AndroidAnnotations does not make the implementation to use a background thread. Actually it should not have to, since it is uncertain whether the call is already on a background thread or not, etc. But you can easily put calls to a background thread with the @Background annotation. With the usage of that, you can simply avoid the AsyncTask boilerplate.

Upvotes: 1

Priyank Patel
Priyank Patel

Reputation: 12382

The exception that is thrown when an application attempts to perform a networking operation on its main thread.

This is only thrown for applications targeting the Honeycomb SDK or higher. Applications targeting earlier SDK versions are allowed to do networking on their main event loop threads, but it's heavily discouraged. See the document Designing for Responsiveness.

The most effecive way to create a worker thread for longer operations is with the AsyncTask class. Simply extend AsyncTask and implement the doInBackground() method to perform the work. To post progress changes to the user, you can call publishProgress(), which invokes the onProgressUpdate() callback method. From your implementation of onProgressUpdate() (which runs on the UI thread), you can notify the user. For example:

private class DownloadFilesTask extends AsyncTask<URL, Integer, Long> {
    // Do the long-running work in here
    protected Long doInBackground(URL... urls) {
        int count = urls.length;
        long totalSize = 0;
        for (int i = 0; i < count; i++) {
            totalSize += Downloader.downloadFile(urls[i]);
            publishProgress((int) ((i / (float) count) * 100));
            // Escape early if cancel() is called
            if (isCancelled()) break;
        }
        return totalSize;
    }

    // This is called each time you call publishProgress()
    protected void onProgressUpdate(Integer... progress) {
        setProgressPercent(progress[0]);
    }

    // This is called when doInBackground() is finished
    protected void onPostExecute(Long result) {
        showNotification("Downloaded " + result + " bytes");
    }
}

To execute this worker thread, simply create an instance and call execute():

new DownloadFilesTask().execute(url1, url2, url3);

Upvotes: 0

Pankaj Deshpande
Pankaj Deshpande

Reputation: 502

You are calling a RESTful web service, which is a network operation. As Android architecture says, network operation should be done on another thread than UI thread. For this you have to start another thread to do that operation, but the best practice is to use AsyncTask

Upvotes: 0

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