Code runs successfully on gingerbird but jelly bean error: android.os.NetworkOnMainThreadException

Question

I'm having trouble when it will submit the data, there was a problem android.os.NetworkOnMainThreadException. Please help me solve this problem. The following source daftar_nama_lokasi.java:

package geotracker.lokasi;

public class daftar_nama_lokasi extends Activity{
private LocationManager lm;
private LocationListener locationListener;
private EditText lat;
private EditText lon;
private EditText nama_lokasi;
private EditText alamat_lokasi;

private EditText kode;

public void onCreate(Bundle savedInstanceState){
    super.onCreate(savedInstanceState);

    setContentView(R.layout.daftar_nama_lokasi);

    lat = (EditText) findViewById(R.id.latitude);
    lon = (EditText) findViewById(R.id.longitude);
    nama_lokasi = (EditText) findViewById(R.id.nama_lokasi);
    alamat_lokasi = (EditText) findViewById(R.id.alamat_lokasi);
    kode = (EditText) findViewById(R.id.imei);
    lat.setEnabled(false);
    lon.setEnabled(false);
    kode.setEnabled(false);


     TelephonyManager telephonyManager = (TelephonyManager)getSystemService(Context.TELEPHONY_SERVICE);
        // mendapatkan nomor imei dan menyimpanya dalam variabel
        String imei = telephonyManager.getDeviceId();
        EditText IMEI = (EditText)findViewById(R.id.imei);
        // menampilkan nomor imei pada EditView yang sudah di buat
        IMEI.setText(imei);


    // ---use the LocationManager class to obtain GPS locations---
    lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
    locationListener = new MyLocationListener();
    lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);

    Button btnSimpan = (Button) findViewById(R.id.btnsimpan);
    btnSimpan.setOnClickListener(
        new OnClickListener() {
            @Override
            public void onClick(View v) {
                JSONObject json = new JSONObject();
                String hasil = "";
                try {
                    json.put("lat", lat.getText());
                    json.put("lon", lon.getText());
                    json.put("location_name", nama_lokasi.getText());
                    json.put("address", alamat_lokasi.getText());
                    json.put("imei", kode.getText());
                    koneksi_internet kn = new koneksi_internet();
                    hasil = kn.postData(json,"nama_lokasi");
                    Toast.makeText(getBaseContext(), hasil, Toast.LENGTH_SHORT).show();
                } catch (JSONException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
    );
}

private class MyLocationListener implements LocationListener {
    //Menampilkan Update Lokasi GPS terkini
    @Override
    public void onLocationChanged(Location loc) {
        if (loc != null) {
            lat.setText(String.valueOf(loc.getLatitude()));
            lon.setText(String.valueOf(loc.getLongitude()));
        }
    }

    @Override
    public void onProviderDisabled(String provider) {
        // TODO Auto-generated method stub
    }

    @Override
    public void onProviderEnabled(String provider) {
        // TODO Auto-generated method stub
    }

    @Override
    public void onStatusChanged(String provider, int status, Bundle extras) {
        // TODO Auto-generated method stub
    }
}
    }//end class

konfigurasi.java

package geotracker.lokasi;

 public class konfigurasi {
final static String URL ="http://localhost/andro/config/index.php?jenis=";
final static int WAKTU = 1;// 1 menit
 }

koneksi_internet.java

package geotracker.lokasi;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;


public class koneksi_internet {
public String test(){
    return konfigurasi.URL;
}

public String postData(JSONObject json, String querystring) throws JSONException{  
    // Create a new HttpClient and Post Header
    HttpClient httpclient = new DefaultHttpClient();
    HttpPost httppost = new HttpPost(konfigurasi.URL+querystring);
    //JSONObject json = new JSONObject();
    String text="";
    try {
        // JSON data:
        JSONArray postjson=new JSONArray();
        postjson.put(json);

        // Post the data:
        httppost.setHeader("json",json.toString());
        httppost.getParams().setParameter("jsonpost",postjson);

        // Execute HTTP Post Request
        System.out.print(json);
        HttpResponse response = httpclient.execute(httppost);

        // for JSON:
        if(response != null)
        {
            InputStream is = response.getEntity().getContent();

            BufferedReader reader = new BufferedReader(new          InputStreamReader(is));
            StringBuilder sb = new StringBuilder();

            String line = null;
            try {
                while ((line = reader.readLine()) != null) {
                    sb.append(line + "\n");// backslash \
                }
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                try {
                    is.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            text = sb.toString();
        }
    }catch (ClientProtocolException e) {
        // TODO Auto-generated catch block
    } catch (IOException e) {
        // TODO Auto-generated catch block
    }
    return text;
}

    }

Answer 1

Android requires long operations like database query or network operations to be done in a separate thread. For this use AsyncTask because it provides painless threading because it synchronizes your Ui and background thread. So do your network operation inside doInBackground function of AsyncTask.

private class LongOperation extends AsyncTask<String, Void, String> {

    @Override
    protected String doInBackground(String... params) {
postData();
       return null;
    }

    @Override
    protected void onPostExecute(String result) {
        // runs in ui thread so update views here
    }

    @Override
    protected void onPreExecute() {
//runs in ui thread start progress dialog here
}

}