Java tutorial
/** * Copyright 2013 Bhavyanshu Parasher * This file is part of "ITM University Android Application". * "ITM University Android Application" is free software: you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the Free Software Foundation, * either version 3 of the License, or (at your option) any later version. * "ITM University Android Application" is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. * You should have received a copy of the GNU General Public License along with "ITM University Android Application". * If not, see http://www.gnu.org/licenses/. */ /** * This activity is used to fetch all questions in Talky. */ package com.wbs.itm; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import org.apache.http.NameValuePair; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; import com.google.analytics.tracking.android.EasyTracker; import android.app.ListActivity; import android.app.ProgressDialog; import android.content.Intent; import android.os.AsyncTask; import android.os.Bundle; import android.util.Log; import android.view.View; import android.widget.AdapterView; import android.widget.AdapterView.OnItemClickListener; import android.widget.ListAdapter; import android.widget.ListView; import android.widget.SimpleAdapter; import android.widget.TextView; public class AllQuestionActivity extends ListActivity { private ProgressDialog pDialog; JSONParser jParser = new JSONParser(); ArrayList<HashMap<String, String>> questionsList; private static String url_all_questions = "http://thewbs.getfreehosting.co.uk/talky/fetchqs.php"; // JSON Node names private static final String TAG_SUCCESS = "success"; private static final String TAG_QUES = "ques"; private static final String TAG_PID = "qid"; private static final String TAG_NAME = "name"; private static final String TAG_INFO = "question"; private static final String TAG_DATE = "date"; JSONArray questions = null; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.all_ques); questionsList = new ArrayList<HashMap<String, String>>(); new LoadAllQuestions().execute(); ListView lv = getListView(); lv.setOnItemClickListener(new OnItemClickListener() { @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { String pid = ((TextView) view.findViewById(R.id.qid)).getText().toString(); String question = ((TextView) view.findViewById(R.id.question)).getText().toString(); Intent myIntent = new Intent(AllQuestionActivity.this, SelectedQuestionActivity.class); myIntent.putExtra("TAG_PID", pid); myIntent.putExtra("TAG_QUESTION", question); AllQuestionActivity.this.startActivity(myIntent); } }); } @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { super.onActivityResult(requestCode, resultCode, data); // if result code 100 if (resultCode == 100) { Intent intent = getIntent(); finish(); startActivity(intent); } } /** * Background Async Task to Load all questions by making HTTP Request * */ class LoadAllQuestions extends AsyncTask<String, String, String> { /** * Before starting background thread Show Progress Dialog * */ @Override protected void onPreExecute() { super.onPreExecute(); pDialog = new ProgressDialog(AllQuestionActivity.this); pDialog.setMessage("Loading Questions. Please wait..."); pDialog.setIndeterminate(false); pDialog.setCancelable(false); pDialog.show(); } /** * getting data from url * */ @Override protected String doInBackground(String... args) { List<NameValuePair> params = new ArrayList<NameValuePair>(); JSONObject json = jParser.makeHttpRequest(url_all_questions, "GET", params); Log.d("All questions: ", json.toString()); //Important for logcat analysis try { // Checking for SUCCESS TAG int success = json.getInt(TAG_SUCCESS); if (success == 1) { questions = json.getJSONArray(TAG_QUES); for (int i = 0; i < questions.length(); i++) { JSONObject c = questions.getJSONObject(i); String id = c.getString(TAG_PID); String name = c.getString(TAG_NAME); String info = c.getString(TAG_INFO); String date = c.getString(TAG_DATE); HashMap<String, String> map = new HashMap<String, String>(); map.put(TAG_PID, id); map.put(TAG_NAME, name); map.put(TAG_INFO, info); map.put(TAG_DATE, date); questionsList.add(map); } } else { //If nothing found then call activity for adding a new question ;) Intent i = new Intent(getApplicationContext(), NewQuestionActivity.class); i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP); startActivity(i); } } catch (JSONException e) { e.printStackTrace(); } return null; } /** * After completing background task Dismiss the progress dialog * **/ @Override protected void onPostExecute(String file_url) { pDialog.dismiss(); runOnUiThread(new Runnable() { @Override public void run() { /** * Updating parsed JSON data into ListView * */ ListAdapter adapter = new SimpleAdapter(AllQuestionActivity.this, questionsList, R.layout.list_item_ques, new String[] { TAG_PID, TAG_NAME, TAG_INFO, TAG_DATE }, new int[] { R.id.qid, R.id.name, R.id.question, R.id.date }); setListAdapter(adapter); } }); } } @Override protected void onStart() { super.onStart(); EasyTracker.getInstance().activityStart(this); // Add this method } @Override protected void onStop() { super.onStop(); EasyTracker.getInstance().activityStop(this); // Add this method } }