App working fine in emulator but showing networkonmainthread exception

Question

I have created an app which retrieves the data from a url using xml pull parser.It is working fine on emulator but when i test it in tab it is showing networkonmainthread exception.My code is:

package com.example.androidsample4;
import java.io.IOException;
import java.io.InputStream;
import java.net.URI;
import java.net.URL;

import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
import org.xmlpull.v1.XmlPullParserFactory;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import android.content.res.Resources;
import android.content.res.XmlResourceParser;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ArrayAdapter;
import android.widget.AutoCompleteTextView;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

public class UNIXclass extends Activity 
{
    String unixcommands[];

    AutoCompleteTextView actv1;

    protected URL params;
    static final String URL="http://cympac.com/apps/xmlfile.xml";
    static final String KEY_COMMAND = "command"; // parent node
    static final String KEY_WORD = "word";
    static final String KEY_EXPLANATION = "explanation";


    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        TextView tv1=(TextView)findViewById(R.id.textView1);
        AutoCompleteTextView actv=(AutoCompleteTextView)findViewById(R.id.autoCompleteTextView1);
        Button b1=(Button)findViewById(R.id.button1);
        unixcommands=getResources().getStringArray(R.array.Commands);
        ArrayAdapter<String> adapter =new ArrayAdapter<String>(getBaseContext(), android.R.layout.simple_list_item_1,unixcommands);
        actv1 = (AutoCompleteTextView)findViewById(R.id.autoCompleteTextView1);
        actv1.setThreshold(1);
        actv1.setAdapter(adapter);
        b1.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) 
            {
                Mytask task=new Mytask();
                task.doInBackground(params);


            }
        });
    }
    private class Mytask extends AsyncTask<java.net.URL, Void, Void>
    {

        @Override
        protected Void doInBackground(java.net.URL... params) 
        {
            TextView myXmlContent = (TextView)findViewById(R.id.textView2);
            String stringXmlContent = null;
            try {
                stringXmlContent = getEventsFromAnXML();   //   54 line
            } catch (XmlPullParserException e) {
                // TODO Auto-generated catch block
                Toast.makeText(getBaseContext(), "error:"+e.getMessage(), Toast.LENGTH_SHORT).show();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                Toast.makeText(getBaseContext(), "error:"+e.getMessage(), Toast.LENGTH_SHORT).show();
            }
            myXmlContent.setText(stringXmlContent);
            return null;

        }

    }
    public String getEventsFromAnXML() throws XmlPullParserException,IOException
    {
        StringBuffer stringBuffer=new StringBuffer();

        java.net.URL url=new java.net.URL("http://cympac.com/apps/xmlfile.xml");
        XmlPullParserFactory factory=XmlPullParserFactory.newInstance();
        factory.setNamespaceAware(true);
        XmlPullParser xpp=factory.newPullParser();
        //xpp.setInput(getInputStream(url),"UTF-8");         //84 line
        xpp.setInput(url.openConnection().getInputStream(), "UTF-8");
        int eventType = xpp.getEventType();
        String word = null;

        String tag;
        while ((eventType = xpp.next()) != XmlPullParser.END_DOCUMENT)
        {
            if(XmlPullParser.START_TAG==eventType)
            {
                tag=xpp.getName();
                //stringBuffer.append("\n"+tag);
                if (tag.equals("word"))
                {
                    eventType = xpp.next();
                    word = xpp.getText();
                }
                else if (tag.equals("explanation"))
                {
                    eventType = xpp.next();
                   //if ("cancel".equals(word))
                    if(actv1.getText().toString().equals(word))

                    {
                        stringBuffer.append("\n" + xpp.getText());
                    }
                }

            }

        }
        return stringBuffer.toString();



    }



}

I read that when we have to use network then we shuld use Asynctask.So i used it,But still it is showing the same error. Please help me to solve this. logcat o/p

08-21 16:36:41.087 E/AndroidRuntime( 4076): FATAL EXCEPTION: main
08-21 16:36:41.087 E/AndroidRuntime( 4076): android.os.NetworkOnMainThreadException
08-21 16:36:41.087 E/AndroidRuntime( 4076): at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1077)
08-21 16:36:41.087 E/AndroidRuntime( 4076): at java.net.InetAddress.lookupHostByName(InetAddress.java:477)
08-21 16:36:41.087 E/AndroidRuntime( 4076): at java.net.InetAddress.getAllByNameImpl(InetAddress.java:277)
08-21 16:36:41.087 E/AndroidRuntime( 4076): at java.net.InetAddress.getAllByName(InetAddress.java:249)
08-21 16:36:41.087 E/AndroidRuntime( 4076): at org.apache.harmony.luni.internal.net.www.protocol.http.HttpConnection.<init>(HttpConnection.java:69)
08-21 16:36:41.087 E/AndroidRuntime( 4076): at org.apache.harmony.luni.internal.net.www.protocol.http.HttpConnection.<init>(HttpConnection.java:48)
08-21 16:36:41.087 E/AndroidRuntime( 4076): at org.apache.harmony.luni.internal.net.www.protocol.http.HttpConnection$Address.connect(HttpConnection.java:304)
08-21 16:36:41.087 E/AndroidRuntime( 4076): at org.apache.harmony.luni.internal.net.www.protocol.http.HttpConnectionPool.get(HttpConnectionPool.java:89)
08-21 16:36:41.087 E/AndroidRuntime( 4076): at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.getHttpConnection(HttpURLConnectionImpl.java:292)
08-21 16:36:41.087 E/AndroidRuntime( 4076): at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.makeConnection(HttpURLConnectionImpl.java:274)
08-21 16:36:41.087 E/AndroidRuntime( 4076): at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.retrieveResponse(HttpURLConnectionImpl.java:1038)
08-21 16:36:41.087 E/AndroidRuntime( 4076): at org.apache.harmony.luni.internal.net.www.protocol.http.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:523)
08-21 16:36:41.087 E/AndroidRuntime( 4076): at com.example.androidsample4.SANclass.getEventsFromAnXML(SANclass.java:115)
08-21 16:36:41.087 E/AndroidRuntime( 4076): at com.example.androidsample4.SANclass$Mytask.doInBackground(SANclass.java:92)
08-21 16:36:41.087 E/AndroidRuntime( 4076): at com.example.androidsample4.SANclass$1.onClick(SANclass.java:58)
08-21 16:36:41.087 E/AndroidRuntime( 4076): at android.view.View.performClick(View.java:3131)
08-21 16:36:41.087 E/AndroidRuntime( 4076): at android.view.View$PerformClick.run(View.java:12035)
08-21 16:36:41.087 E/AndroidRuntime( 4076): at android.os.Handler.handleCallback(Handler.java:587)
08-21 16:36:41.087 E/AndroidRuntime( 4076): at android.os.Handler.dispatchMessage(Handler.java:92)
08-21 16:36:41.087 E/AndroidRuntime( 4076): at android.os.Looper.loop(Looper.java:132)
08-21 16:36:41.087 E/AndroidRuntime( 4076): at android.app.ActivityThread.main(ActivityThread.java:4123)
08-21 16:36:41.087 E/AndroidRuntime( 4076): at java.lang.reflect.Method.invokeNative(Native Method)
08-21 16:36:41.087 E/AndroidRuntime( 4076): at java.lang.reflect.Method.invoke(Method.java:491)
08-21 16:36:41.087 E/AndroidRuntime( 4076): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:844)
08-21 16:36:41.087 E/AndroidRuntime( 4076): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:602)
08-21 16:36:41.087 E/AndroidRuntime( 4076): at dalvik.system.NativeStart.main(Native Method)
08-21 16:36:41.092 V/AudioPolicyManager( 2713): releaseOutput() 1
08-21 16:36:41.092 W/ActivityManager( 2891):   Force finishing activity com.example.androidsample4/.SANclass

I am getting force close if i include "new Mytask.execute()" method.What could be the reason for this?Please guide me...

post the logcat output also?? – Dinesh Anuruddha Aug 21 '12 at 11:23 — Dinesh Anuruddha, Aug 21 '12 at 11:23

score 3 · Accepted Answer · edited May 23 '17 at 11:48

3

Dont update the UI in back ground thread.It should be done in onPostExecute()

Toast.makeText(getBaseContext(), "error:"+e.getMessage(), Toast.LENGTH_SHORT).show();
myXmlContent.setText(stringXmlContent);

Do this steps in onPostExecute()

Read my previous post

edited May 23 '17 at 11:48

Community

1
1

answered Aug 21 '12 at 13:50

Abhi

8,935
7
37
60

score 0 · Answer 2 · edited Aug 21 '12 at 13:32

0

task.doInBackground(params) just calls this method in the same thread. To run AsyncTask not in UI thread you have to call execute() method.

edited Aug 21 '12 at 13:32

Rostyslav Dzinko

39,424
5
49
62

answered Aug 21 '12 at 11:26

Fedor Kazakov

601
3
12

I didnt get...Please elaborate – user1387035 Aug 21 '12 at 11:30

Dinesh Anuruddha · Answer 3 · 2012-08-21T11:39:58.450

0

you should call background thread as followings.

b1.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) 
            {

                new Mytask().execute(params);


            }
        });

edited Aug 21 '12 at 11:39

answered Aug 21 '12 at 11:30

Dinesh Anuruddha

7,137
6
32
45

@user1387035 - If u want to pass any argument to doInBackground, u can pass through execute(...) – Braj Aug 21 '12 at 11:36
new Mytask().execute("pass what you need hear"); – Dinesh Anuruddha Aug 21 '12 at 11:37

App working fine in emulator but showing networkonmainthread exception

3 Answers3