Android - Android.Os.Networkonmainthreadexception

How can I fix 'android.os.NetworkOnMainThreadException'?

NOTE : AsyncTask was deprecated in API level 30.

AsyncTask | Android Developers

This exception is thrown when an application attempts to perform a networking operation on its main thread. Run your code in AsyncTask:

class RetrieveFeedTask extends AsyncTask<String, Void, RSSFeed> {

    private Exception exception;

    protected RSSFeed doInBackground(String... urls) {
        try {
            URL url = new URL(urls[0]);
            SAXParserFactory factory = SAXParserFactory.newInstance();
            SAXParser parser = factory.newSAXParser();
            XMLReader xmlreader = parser.getXMLReader();
            RssHandler theRSSHandler = new RssHandler();
            xmlreader.setContentHandler(theRSSHandler);
            InputSource is = new InputSource(url.openStream());
            xmlreader.parse(is);

            return theRSSHandler.getFeed();
        } catch (Exception e) {
            this.exception = e;

            return null;
        } finally {
            is.close();
        }
    }

    protected void onPostExecute(RSSFeed feed) {
        // TODO: check this.exception
        // TODO: do something with the feed
    }
}

How to execute the task:

In MainActivity.java file you can add this line within your oncreate() method

new RetrieveFeedTask().execute(urlToRssFeed);

Don't forget to add this to AndroidManifest.xml file:

<uses-permission android:name="android.permission.INTERNET"/>

Android - android.os.NetworkOnMainThreadException

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

You should call sendfeedback method on asynctask then only above code will work. As webserver is taking lot of time to response main thread becomes unresponsive. To avoid it you should call it on another thread. Hence asynctask is better.

here is link that illustrates how to use asynctask

How to fix NetworkonMainThreadException in Android?

Your Exception actually tells you exactly what you are doing wrong. You are not using another thread to perform NetworkOperations. Instead, you perform the network operation on your UI-Thread, which cannot (does not) work on Android.

Your code that connects to the url should be executed for example inside an AsyncTasks doInBackground() method, off the UI-Thread.

Take a look at this question on how to use the AsyncTask: How to use AsyncTask

Why do I get android.os.NetworkOnMainThreadException when I run the class on a separate thread (implementing Runnable)?

In the else part, you are calling run methods directly which will execute the network call on mail thread, hence the exception

// this method is being called in onResume so
// second time, mQueueWorkerThread.run will be executed on main thread
private void startQueueWorkerThread(){
    if (mQueueWorkerThread == null){
        mQueueWorkerThread = new QueueWorkerThread(mContext,this, this);
        new Thread(mQueueWorkerThread).start();
    } else {
        mQueueWorkerThread.makeReady();
        mQueueWorkerThread.run(); // it will cause the exception
        // new Thread(mQueueWorkerThread).start(); should use this
    }
}

android.os.NetworkOnMainThreadException Exception

you are not suppose to do network operations on the ui/Main thread i know you are using async task but this is why you get the error look at your code here

getActivity().runOnUiThread(new Runnable() {public void run() {});

this makes it run on the ui thread despite async task beauty.. i'd suggest you remove this code and let async task work and use postexecute to post to the ui thread..

how do i fix FATAL EXCEPTION:main android.os.NetworkOnMainThreadException

The issue is that inside the AsyncTask's onPostExecute you call the following:

socket.getOutputStream() 

This happens on the MainThread and therefore the exception is thrown. Move it to the doInBackground inside the try catch block so it looks like this:

public class ConnectPhoneTask extends AsyncTask<String,Void,Boolean> {

    @Override
    protected Boolean doInBackground(String... params) {
        boolean result = true;
        try {
            InetAddress serverAddr = InetAddress.getByName(params[0]);
            socket = new Socket(serverAddr, Constants.SERVER_PORT);//Open socket on server IP and port
            if(isConnected) {
                out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket
                        .getOutputStream())), true); //create output stream to send data to server
            }
        } catch (IOException e) {
            Log.e("remotedroid", "Error while connecting", e);
            result = false;
        }
        return result;
    }

    @Override
    protected void onPostExecute(Boolean result)
    {
        isConnected = result;
        Toast.makeText(context,isConnected?"Connected to server!":"Error while connecting",Toast.LENGTH_LONG).show();
    }
}

Android.OS.NetworkOnMainThreadException in

FindInBackground's done callback method runs on UI thread and not on the async thread

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