Retrieve data from URL and return as JSON and then processed by this Activity in AsyncTask.

MataKuliahActivity

package com.fanjavaid.valore.app;

import android.app.ActionBar;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.ListActivity;
import android.app.ProgressDialog;
import android.app.SearchManager;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.text.TextUtils;
import android.util.Log;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SearchView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
import android.widget.Toast;

import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import org.json.JSONParser;

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

public class MataKuliahActivity extends ListActivity implements SearchView.OnQueryTextListener {

    private ListView lv;
    private Context context;
    private static String url_all_data = "http://fanjavaid.com/droidunindra/proc_select_matkul.php";

    private ProgressDialog pDialog;
    
    // Membuat JSON Parser Object
    JSONParser parser = new JSONParser();
    ArrayList<HashMap<String, String>> matkulList;

    private static final String TAG_SUCCESS = "success";
    private static final String TAG_MATKULS = "list_matkul";
    private static final String TAG_MID = "id";
    private static final String TAG_NAME = "matkul";

    JSONArray matkuls  = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_mata_kuliah);

        matkulList = new ArrayList<HashMap<String, String>>();

        new LoadMatkuls().execute();

        lv = getListView();

        lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
                String mid = ((TextView) view.findViewById(R.id.id)).getText().toString();

                // Starting new intent
                // Intent intent = new Intent(getApplicationContext(), )
                context = getApplicationContext();
                Toast.makeText(context,mid,Toast.LENGTH_SHORT).show();
            }
        });

        lv.setTextFilterEnabled(true);

        ActionBar ab = getActionBar();
        ab.setDisplayHomeAsUpEnabled(true);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.mata_kuliah, menu);

        SearchManager searchManager = (SearchManager) getSystemService(Context.SEARCH_SERVICE);
        SearchView searchView = (SearchView) menu.findItem(R.id.action_search).getActionView();
        searchView.setSearchableInfo(searchManager.getSearchableInfo(getComponentName()));
        searchView.setSubmitButtonEnabled(true);
        searchView.setOnQueryTextListener(this);

        return super.onCreateOptionsMenu(menu);
    }
    @Override
    public boolean onQueryTextChange(String newText) {
        if (TextUtils.isEmpty(newText)) {
            lv.clearTextFilter();
        } else {
            lv.setFilterText(newText.toString());
        }

        return true;
    }

    @Override
    public boolean onQueryTextSubmit(String query) {
        return false;
    }

    class LoadMatkuls extends AsyncTask<String, String, String> {
        protected void onPreExecute() {
            super.onPreExecute();
            pDialog = new ProgressDialog(MataKuliahActivity.this);
            pDialog.setMessage("Loading Data");
            pDialog.setIndeterminate(false);
            pDialog.setCancelable(false);
            pDialog.show();
        }

        protected String doInBackground(String... args) {
            Intent intent = getIntent();
            String semesterId = intent.getStringExtra("semesterId");

            List<NameValuePair> params = new ArrayList<NameValuePair>();
            params.add(new BasicNameValuePair("semester", semesterId));

            JSONObject json = parser.makeHttpRequest(url_all_data, "GET", params);
            Log.d("All Datas : ", json.toString());

            try {
                int success = json.getInt(TAG_SUCCESS);

                if (success == 1) {
                    // Data ditemukan
                    // Dapatkan array dari product
                    matkuls = json.getJSONArray(TAG_MATKULS);

                    // looping data
                    for (int i = 0; i < matkuls.length(); i++) {
                        JSONObject c = matkuls.getJSONObject(i);

                        // Simpan tiap data ke variabel
                        String id = c.getString(TAG_MID);
                        String name = c.getString(TAG_NAME);

                        // Buat HashMap
                        HashMap<String, String> map = new HashMap<String, String>();

                        // Tambahkan setiap child dari node ke HashMap
                        map.put(TAG_MID, id);
                        map.put(TAG_NAME, name);

                        matkulList.add(map);
                    }
                } else {
                    // Data tidak ditemukan
                    //context = getApplicationContext();
                    Toast.makeText(MataKuliahActivity.this, "Data gagal diload", Toast.LENGTH_SHORT).show();
                }

            } catch (JSONException e) {
                e.printStackTrace();
            }

            return null;
        }

        protected void onPostExecute(String file_url) {
            pDialog.dismiss();

            // Update UI dari Background Thread
            runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    // Updating parsed JSON Data ke ListView
                    ListAdapter adapter = new SimpleAdapter(
                            MataKuliahActivity.this, matkulList,
                            R.layout.list_matkul, new String [] {TAG_MID, TAG_NAME},
                            new int [] {R.id.id, R.id.matkul});

                    setListAdapter(adapter);
                }
            });
        }
    }

}