android.os.NetworkOnMainThreadException with android 4.2

Question

Here i am using this code load Json. It is work fine with android 2.2 but when i am using android 4.2 it throws android.os.NetworkOnMainThreadException exception please give me solution

 public class JSONParser {

    static InputStream is = null;

static JSONObject jObj = null;
static String json = "";

// constructor
public JSONParser() {

}

public JSONObject getJSONFromUrl(String url) {

    // Making HTTP request
    try {
        // defaultHttpClient
        DefaultHttpClient httpClient = new DefaultHttpClient();
        HttpGet httpPost = new HttpGet(url);

            HttpResponse getResponse = httpClient.execute(httpPost);
           final int statusCode = getResponse.getStatusLine().getStatusCode();

           if (statusCode != HttpStatus.SC_OK) { 
              Log.w(getClass().getSimpleName(), 
                  "Error " + statusCode + " for URL " + url); 
              return null;
           }

           HttpEntity getResponseEntity = getResponse.getEntity();

        //HttpResponse httpResponse = httpClient.execute(httpPost);
        //HttpEntity httpEntity = httpResponse.getEntity();
        is = getResponseEntity.getContent();            

    } catch (UnsupportedEncodingException e) {
        e.printStackTrace();
    } catch (ClientProtocolException e) {
        e.printStackTrace();
    } catch (IOException e) {
        Log.d("IO", e.getMessage().toString());
        e.printStackTrace();

    }

    try {
        BufferedReader reader = new BufferedReader(new InputStreamReader(
                is, "iso-8859-1"), 8);
        StringBuilder sb = new StringBuilder();
        String line = null;
        while ((line = reader.readLine()) != null) {
            sb.append(line + "\n");
        }
        is.close();
        json = sb.toString();
    } catch (Exception e) {
        Log.e("Buffer Error", "Error converting result " + e.toString());
    }

    // try parse the string to a JSON object
    try {
        jObj = new JSONObject(json);
    } catch (JSONException e) {
        Log.e("JSON Parser", "Error parsing data " + e.toString());
    }

    // return JSON String
    return jObj;

}

}

i am also using google api.

Question has been answered here: http://stackoverflow.com/questions/5150637/networkonmainthreadexception — Patrick D, May 08 '13 at 11:35

score 81 · Accepted Answer · answered May 08 '13 at 11:38

81

Write below code into your MainActivity file after setContentView(R.layout.activity_main);

if (android.os.Build.VERSION.SDK_INT > 9) {
    StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
    StrictMode.setThreadPolicy(policy);
}

And below import statement into your java file.

import android.os.StrictMode;

answered May 08 '13 at 11:38

Nirav Ranpara

13,753
3
39
54

41

it is not the correct way to turn off StrictMode. The correct way is to call network operations in AsyncTask instead of turning off – Sankar V May 08 '13 at 11:40
As @SankarV says it should be done using an AsyncTask instead of turning off strictmode. – Mr.Noob Oct 09 '13 at 08:29
This is not recommended. AsyncTask is a better way to do this. – Hiten Naresh Vasnani Aug 25 '15 at 05:31
so many bunches of solutions recommended but none of them solved the problem except this one. – Maria Cecilia Ancheta Calianga Aug 30 '21 at 10:56

score 13 · Answer 2 · answered May 08 '13 at 11:56

This is the correct way:

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

    static InputStream is = null;

static JSONObject jObj = null;
static String json = "";

// constructor
public JSONParser() {

}
@Override
protected String doInBackground(String... params) {


    // Making HTTP request
    try {
        // defaultHttpClient
        DefaultHttpClient httpClient = new DefaultHttpClient();
        HttpGet httpPost = new HttpGet(url);

            HttpResponse getResponse = httpClient.execute(httpPost);
           final int statusCode = getResponse.getStatusLine().getStatusCode();

           if (statusCode != HttpStatus.SC_OK) { 
              Log.w(getClass().getSimpleName(), 
                  "Error " + statusCode + " for URL " + url); 
              return null;
           }

           HttpEntity getResponseEntity = getResponse.getEntity();

        //HttpResponse httpResponse = httpClient.execute(httpPost);
        //HttpEntity httpEntity = httpResponse.getEntity();
        is = getResponseEntity.getContent();            

    } catch (UnsupportedEncodingException e) {
        e.printStackTrace();
    } catch (ClientProtocolException e) {
        e.printStackTrace();
    } catch (IOException e) {
        Log.d("IO", e.getMessage().toString());
        e.printStackTrace();

    }

    try {
        BufferedReader reader = new BufferedReader(new InputStreamReader(
                is, "iso-8859-1"), 8);
        StringBuilder sb = new StringBuilder();
        String line = null;
        while ((line = reader.readLine()) != null) {
            sb.append(line + "\n");
        }
        is.close();
        json = sb.toString();
    } catch (Exception e) {
        Log.e("Buffer Error", "Error converting result " + e.toString());
    }

    // try parse the string to a JSON object
    try {
        jObj = new JSONObject(json);
    } catch (JSONException e) {
        Log.e("JSON Parser", "Error parsing data " + e.toString());
    }

    // return JSON String
    return jObj;


}
protected void onPostExecute(String page)
{   
    //onPostExecute
}   
}

To call it (from main):

mJSONParser = new JSONParser();
mJSONParser.execute();

did you even test that? Does not work what's that url? return obj is not accessible its outside the loop — Nasz Njoka Sr., Apr 03 '14 at 09:32

Arun C · Answer 3 · 2013-05-08T11:43:59.230

6

Please make sure that you don't do any network access on UI Thread, instead do it in Async Task

The reason why your application crashes on Android versions 3.0 and above, but works fine on Android 2.x is because since HoneyComb are much stricter about abuse against the UI Thread. For example, when an Android device running HoneyComb or above detects a network access on the UI thread, a NetworkOnMainThreadException will be thrown.

See this

edited May 08 '13 at 11:43

answered May 08 '13 at 11:36

Arun C

9,035
2
28
42

instead of HoneyComb and Ice Cream Sandwich I will say Since HoneyComb. In fact JB has the same policy – Blackbelt May 08 '13 at 11:42

score 1 · Answer 4 · edited May 23 '17 at 12:26

android.os.NetworkOnMainThreadException occurs when you try to access network on your main thread (You main activity execution). To avoid this, you must create a separate thread or AsyncTask or Runnable implementation to execute your JSON data loading. Since HoneyComb you can not further execute the network task on main thread. Here is the implementation using AsyncTask for a network task execution

score 1 · Answer 5 · answered May 08 '13 at 11:39

1

Use StrictMode Something like this:-

   if (android.os.Build.VERSION.SDK_INT > 9) {
        StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();

        StrictMode.setThreadPolicy(policy); 
        }

answered May 08 '13 at 11:39

Deepanker Chaudhary

1,694
3
15
35

2

it is not the correct way to turn off StrictMode. The correct way is to call network operations in AsyncTask instead of turning off. is they provided the check just for turning off? – Sankar V May 08 '13 at 11:42
we can use asynkTask also but for me its working – Deepanker Chaudhary May 08 '13 at 11:45
ya it will work but not the best way. they have provided the check to ensure developer calls the network operations in separate thread not for simply turning off. – Sankar V May 08 '13 at 11:51
ohh! thanx asyncTask is good – Deepanker Chaudhary May 08 '13 at 11:53

android.os.NetworkOnMainThreadException with android 4.2

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