Android AsyncTask to read data from a URL returns android.os.NetworkOnMainThreadException

Question

I'm new to Android and am making a global a high score feature for a simple minesweeper game I've made. I made the highscore feature using PHP so it just visits a URL with some get parameters and the score is saved automatically. To get the score is similar it should read the JSON contents of the URL into a String.

I know you can't access the network from the main thread so I created a AsyncTask. I then call it from my activity.

But I still get the error android.os.NetworkOnMainThreadException

Below is the AsyncTask class

package net.as93.minesweeper.util;

import android.os.AsyncTask;

import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.protocol.BasicHttpContext;
import org.apache.http.protocol.HttpContext;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Eventupdate extends AsyncTask<String, Void, Void> {

String pageContents;

@Override
protected Void doInBackground(String... url) {
    try {

        Thread.sleep(4000);

        HttpClient httpClient = new DefaultHttpClient();
        HttpContext localContext = new BasicHttpContext();
        HttpGet httpGet = new HttpGet(url[0]);
        HttpResponse response = httpClient.execute(httpGet,localContext);
        String result = "";
        BufferedReader reader = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));

        String line = null;
        while ((line = reader.readLine()) != null) {
            result += line + "\n";
        }
        pageContents = result;

    } catch (InterruptedException e) {
        System.out.println(e);
        e.printStackTrace();


    } catch (ClientProtocolException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

    // TODO Auto-generated method stub
    return null;
}

public String getPageContents() {
    return pageContents;
}

}

And here is the saveScore() method that should call the AsyncTask

public void saveScore(ScoreObj scoreObj) throws IOException {
        String usersname = scoreObj.getUsersName();
        String time = Integer.toString(scoreObj.getTime());
        String mode = scoreObj.getGameMode();
        String timed = ((scoreObj.isTimed()) ? "true" : "false");

        String myUri = "http://android.as93.net/minesweeper/setscore.php?usersname="+usersname+"&time="+time+"&timed="+timed+"&mode="+mode;
        try{
            Eventupdate eu = new Eventupdate();
            eu.execute(myUri);
            eu.doInBackground(myUri);


        }catch (Exception e){System.out.println("Another error: "+e);}


    }

I have already added <uses-permission android:name="android.permission.INTERNET"/> to the manifest

I have been trying to figure this out for so many hours, can't find the solution on the internet anywhere. Thanks in advance for any suggestions

Use an Asynctask for this purpose or http://blog.vogella.com/2012/02/22/android-strictmode-networkonmainthreadexception/ — Atul O Holic, Apr 15 '14 at 14:36
I am using an Asynctask I think - Eventupdate extends AsyncTask ? — Alicia Sykes, Apr 15 '14 at 14:36
Ooppss my bad, remove this line - eu.doInBackground(myUri); and you shall be fine — Atul O Holic, Apr 15 '14 at 14:39
@Lissy still the same exception after removing `eu.doInBackground(myUri);`??? — Raghunandan, Apr 15 '14 at 14:43
possible duplicate of [android.os.NetworkOnMainThreadException](http://stackoverflow.com/questions/6343166/android-os-networkonmainthreadexception) — Jorgesys, Apr 15 '14 at 14:44
Ah that exceptions gone now - thanks :) although it's not working, just no error at all :/ — Alicia Sykes, Apr 15 '14 at 14:45
The page contents returns null, when it should be either 1 or 0, and looking at the server it hasn't even visited that page — Alicia Sykes, Apr 15 '14 at 14:47
@Lissy remove this `Thread.sleep(4000);` and log some info in doInbackground and check the logcat — Raghunandan, Apr 15 '14 at 14:49
Thanks for your help @Raghunandan Okay, got this error: java.net.UnknownHostException: Unable to resolve host "android.as93.net": No address associated with hostname That sounded to me like a problem with the URL, but it can't be I've checked it and should be working fine - any ideas? — Alicia Sykes, Apr 15 '14 at 14:58
@Lissy yes it certainly problem with the url. Cross check again — Raghunandan, Apr 15 '14 at 14:58

score 2 · Answer 1 · answered Apr 15 '14 at 14:36

2

Remove this

eu.doInBackground(myUri);

You already have

eu.execute(myUri);

When you call execute AsyncTask in invoked and doInbackground does background computation

answered Apr 15 '14 at 14:36

Raghunandan

132,755
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score 2 · Accepted Answer · answered Apr 15 '14 at 14:36

2

this part right here is suspect

Eventupdate eu = new Eventupdate();
eu.execute(myUri);
eu.doInBackground(myUri);

do not directly call doInBackground when you call execute it will call that itself

answered Apr 15 '14 at 14:36

tyczj

71,600
54
194
296

Sorry for not accepting this sooner, only just saw it hadn't been accepted. Thanks for the answer, clearly put +1 – Alicia Sykes Apr 27 '17 at 12:18

score 2 · Answer 3 · answered Apr 15 '14 at 14:37

2

In the try block remove eu.doInBackground(myUri);

answered Apr 15 '14 at 14:37

Toochka

894
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score 0 · Answer 4 · edited Apr 15 '14 at 16:08

0

Remove this line

eu.doInBackground(myUri);

edited Apr 15 '14 at 16:08

Andrew Barber

39,603
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answered Apr 15 '14 at 14:45

engr. Sheraz Khan

54
5

Android AsyncTask to read data from a URL returns android.os.NetworkOnMainThreadException

4 Answers4