Hello i have this code and it gives me errors on android 3 and

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Asked: June 13, 20262026-06-13T10:46:36+00:00 2026-06-13T10:46:36+00:00

Hello i have this code and it gives me errors on android 3 and

0

Hello i have this code and it gives me errors on android 3 and 4 devices.
I know that i can solve this with async but i haven’t worked with sync task before and don’t have a clue how this works. can someone give me a little example with my code or a suggestion how to implement it?

my code:

package com.wemait.obd.emmen;

import java.util.ArrayList;
import java.util.HashMap;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import com.wemait.obd.emmen.JSONParser;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListView;

public class Nieuws extends Activity {


// url om request te maken
private static String URL = "http://www.iappministrator.com/OBDE/webservice/android_news_items.php";

// JSON Node namen
static final String TAG_ITEMS = "items";
static final String TAG_TITLE = "title";
static final String TAG_MESSAGE = "message";
static final String TAG_DATE = "date";
static final String TAG_IMAGES = "images";

// Nieuws JSONArray
JSONArray newsArray = null;

ListView list;
LazyAdapter adapter;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.nieuws);

    // Hashmap voor listView
    final ArrayList<HashMap<String, String>> newsList = new ArrayList<HashMap<String, String>>();

    // Maak een JSON Parser instance
    JSONParser jParser = new JSONParser();

    // Pakt JSON string uit URL
    JSONObject json = jParser.getJSONFromUrl(URL);

    try{
        // Pakt de Array van Nieuwsartikelen
        newsArray = json.getJSONArray(TAG_ITEMS);

        // Loop door alle Nieuwsartikels
        for(int i=0; i < newsArray.length(); i++){
            JSONObject c = newsArray.getJSONObject(i);

            // Het plaatsen van elk json item in variabele
            String title = c.getString(TAG_TITLE);
            String message = c.getString(TAG_MESSAGE);
            //String date = c.getString(TAG_DATE);
            String images = c.getString(TAG_IMAGES);

            // maak een nieuwe HashMap
            HashMap<String, String> map = new HashMap<String, String>();

            // voeg elk item child node in de Hashmap -> value
            map.put(TAG_TITLE, title);
            map.put(TAG_MESSAGE, message);
            //map.put(TAG_DATE, date);
            map.put(TAG_IMAGES, images);


            // voeg de HashList toe aan ArrayList
            newsList.add(map);
        }
    } catch(JSONException e){
        e.printStackTrace();
    }


    list=(ListView)findViewById(R.id.list);

    adapter=new LazyAdapter(this, newsList, R.layout.list_row, 
            new String[]{TAG_TITLE, TAG_MESSAGE, TAG_DATE, TAG_IMAGES}, new int[] {
            R.id.title, R.id.artist, R.id.duration, R.id.list_image});        
    list.setAdapter(adapter);


    // Click event for single list row
    list.setOnItemClickListener(new OnItemClickListener() {

        @Override
        public void onItemClick(AdapterView<?> parent, View view,
                int position, long id) {
              HashMap<String, String> map = newsList.get(position);

             Intent in = new Intent(getApplicationContext(), SingleMenuItemActivity.class);
            //Intent in = new Intent(SingleMenuItemActivity.this, org.scout.android.library.LibraryDetail.class);
            in.putExtra(TAG_TITLE, map.get(TAG_TITLE));
            in.putExtra(TAG_MESSAGE, map.get(TAG_MESSAGE));                         
            in.putExtra(TAG_DATE, map.get(TAG_DATE));
            in.putExtra(TAG_IMAGES, map.get(TAG_IMAGES));

            startActivity(in);
        /* old code public void onItemClick(AdapterView<?> parent, View view,
                int position, long id) {


            String title = ((TextView) view.findViewById(R.id.title)).getText().toString();
            String date = ((TextView) view.findViewById(R.id.duration)).getText().toString();
            String message = ((TextView) view.findViewById(R.id.artist)).getText().toString();
            //String images = ((TextView) view.findViewById(R.id.list_image)).getText().toString();
            //ImageView thumb_image = (ImageView) view.findViewById(R.id.thumbnail); // thumb image
            String images = ((ImageView)view.findViewById(R.id.list_image)).getImageMatrix().toString();
            //String images = ((ImageView)view.findViewById(R.id.list_image)).toString();
            //String images = ((ImageView)view.findViewById(R.id.list_image)).getContext().toString();

            // Start de nieuwe intent

            Intent in = new Intent(getApplicationContext(), SingleMenuItemActivity.class);
            //Bitmap bitmap = (Bitmap) in.getParcelableExtra(TAG_IMAGES);

            in.putExtra(TAG_TITLE, title);
            in.putExtra(TAG_DATE, date);
            in.putExtra(TAG_MESSAGE, message);
            in.putExtra(TAG_IMAGES, images);
            startActivity(in);*/

        }
    });     
}

}

The error i received:

 java.lang.RuntimeException: Unable to start activity ComponentInfo{com.wemait.obd.emmen/com.wemait.obd.emmen.Nieuws}: android.os.NetworkOnMainThreadException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1967)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1992)
at android.app.ActivityThread.access$600(ActivityThread.java:127)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1158)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4511)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:980)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:747)
at dalvik.system.NativeStart.main(Native Method)
Caused by: android.os.NetworkOnMainThreadException
at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1099)
at java.net.InetAddress.lookupHostByName(InetAddress.java:391)
at java.net.InetAddress.getAllByNameImpl(InetAddress.java:242)
at java.net.InetAddress.getAllByName(InetAddress.java:220)
at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:137)
at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
at com.wemait.obd.emmen.JSONParser.getJSONFromUrl(JSONParser.java:38)
at com.wemait.obd.emmen.Nieuws.onCreate(Nieuws.java:53)
at android.app.Activity.performCreate(Activity.java:4470)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1052)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1931)

My adapter class:

    package com.wemait.obd.emmen;

import java.util.ArrayList;
import java.util.HashMap;

import android.app.Activity;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;

public class LazyAdapter extends BaseAdapter {

    private Activity activity;
    private ArrayList<HashMap<String, String>> data;
    private static LayoutInflater inflater=null;
    public ImageLoader imageLoader; 

    public LazyAdapter(Activity a, ArrayList<HashMap<String, String>> d, int listRow, String[] strings, int[] is) {
        activity = a;
        data=d;
        inflater = (LayoutInflater)activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        imageLoader=new ImageLoader(activity.getApplicationContext());
    }

    public int getCount() {
        return data.size();
    }

    public Object getItem(int position) {
        return position;
    }

    public long getItemId(int position) {
        return position;
    }

    public View getView(int position, View convertView, ViewGroup parent) {
        View vi=convertView;
        if(convertView==null)
            vi = inflater.inflate(R.layout.list_row, null);

        TextView title = (TextView)vi.findViewById(R.id.title); // title
        TextView artist = (TextView)vi.findViewById(R.id.artist); // artist name
        TextView duration = (TextView)vi.findViewById(R.id.duration); // duration
        ImageView thumb_image=(ImageView)vi.findViewById(R.id.list_image); // thumb image

        HashMap<String, String> song = new HashMap<String, String>();
        song = data.get(position);

        // Setting all values in listview
        title.setText(song.get(CustomizedListView.TAG_TITLE));
        artist.setText(song.get(CustomizedListView.TAG_MESSAGE));
        duration.setText(song.get(CustomizedListView.TAG_DATE));
        imageLoader.DisplayImage(song.get(CustomizedListView.TAG_IMAGES), thumb_image);
        return vi;
    }
}

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1 Answer

Editorial Team · Answer 1 · 2026-06-13T10:46:37+00:00

Android 3 and 4 have this restriction. You can not run any network related task on main thread. You either have to create a separate thread for this or use async task. I will recommend AsynTask but if you want to solve this by threads then use thread and handler to achieve it. That is how you code will look like if you’ll use AsynTask 🙂

public class Nieuws extends Activity{
private static String URL = "http://www.iappministrator.com/OBDE/webservice/android_news_items.php";

// JSON Node namen
static final String TAG_ITEMS = "items";
static final String TAG_TITLE = "title";
static final String TAG_MESSAGE = "message";
static final String TAG_DATE = "date";
static final String TAG_IMAGES = "images";

// Nieuws JSONArray
JSONArray newsArray = null;

ListView list;
LazyAdapter adapter;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.nieuws);
    list=(ListView)findViewById(R.id.list);

    new GetJSONData().execute();

}

class GetJSONData extends AsyncTask<Void, Void, ArrayList<HashMap<String, String>>>{

@Override
protected ArrayList<HashMap<String, String>> doInBackground(Void... arg0) {
    // Hashmap voor listView
    final ArrayList<HashMap<String, String>> newsList = new ArrayList<HashMap<String, String>>();

    // Maak een JSON Parser instance
    JSONParser jParser = new JSONParser();

    // Pakt JSON string uit URL
    JSONObject json = jParser.getJSONFromUrl(URL);

    try{
        // Pakt de Array van Nieuwsartikelen
        newsArray = json.getJSONArray(TAG_ITEMS);

        // Loop door alle Nieuwsartikels
        for(int i=0; i < newsArray.length(); i++){
            JSONObject c = newsArray.getJSONObject(i);

            // Het plaatsen van elk json item in variabele
            String title = c.getString(TAG_TITLE);
            String message = c.getString(TAG_MESSAGE);
            //String date = c.getString(TAG_DATE);
            String images = c.getString(TAG_IMAGES);

            // maak een nieuwe HashMap
            HashMap<String, String> map = new HashMap<String, String>();

            // voeg elk item child node in de Hashmap -> value
            map.put(TAG_TITLE, title);
            map.put(TAG_MESSAGE, message);
            //map.put(TAG_DATE, date);
            map.put(TAG_IMAGES, images);


            // voeg de HashList toe aan ArrayList
            newsList.add(map);
        }
    } catch(JSONException e){
        e.printStackTrace();
    }
    return newsList;
}
@Override
protected void onPostExecute(ArrayList<HashMap<String, String>> result) {



    adapter=new LazyAdapter(this, result, R.layout.list_row, 
            new String[]{TAG_TITLE, TAG_MESSAGE, TAG_DATE, TAG_IMAGES}, new int[] {
            R.id.title, R.id.artist, R.id.duration, R.id.list_image});        
    list.setAdapter(adapter);


    // Click event for single list row
    list.setOnItemClickListener(new OnItemClickListener() {

        @Override
        public void onItemClick(AdapterView<?> parent, View view,
                int position, long id) {
              HashMap<String, String> map = newsList.get(position);

             Intent in = new Intent(getApplicationContext(), SingleMenuItemActivity.class);
            //Intent in = new Intent(SingleMenuItemActivity.this, org.scout.android.library.LibraryDetail.class);
            in.putExtra(TAG_TITLE, map.get(TAG_TITLE));
            in.putExtra(TAG_MESSAGE, map.get(TAG_MESSAGE));                         
            in.putExtra(TAG_DATE, map.get(TAG_DATE));
            in.putExtra(TAG_IMAGES, map.get(TAG_IMAGES));

            startActivity(in);

        }
    });
}
}
}

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Hello i have this code and it gives me errors on android 3 and

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