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 fetches everything displayed in the academic calendar section. */ 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 AllAnnActivity extends ListActivity { private ProgressDialog pDialog; // Creating JSON Parser object JSONParser jParser = new JSONParser(); ArrayList<HashMap<String, String>> AnouncementList; private static String url_academic_calendar = "http://thewbs.getfreehosting.co.uk/itmuapp/fetchimp.php"; // JSON Node names private static final String TAG_SUCCESS = "success"; private static final String TAG_ANN = "impa"; private static final String TAG_PID = "impid"; private static final String TAG_NAME = "impname"; private static final String TAG_INFO = "impinfo"; private static final String TAG_DATE = "impdate"; // Announcement Notices JSONArray JSONArray notices = null; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.all_ann); // Hashmap for ListView AnouncementList = new ArrayList<HashMap<String, String>>(); // Loading announcements in Background Thread new LoadAllAnns().execute(); // Get listview ListView lv = getListView(); // on seleting single item lv.setOnItemClickListener(new OnItemClickListener() { @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { // getting values from selected ListItem String pid = ((TextView) view.findViewById(R.id.impinfo)).getText().toString(); // Starting new intent Intent in = new Intent(getApplicationContext(), DownloadManager.class); // sending pid to next activity in.putExtra("pathid", pid); // starting new activity and expecting some response back startActivityForResult(in, 100); } }); } //Check response @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { super.onActivityResult(requestCode, resultCode, data); // if result code 100 if (resultCode == 100) { // if result code 100 is received // reload this screen again Intent intent = getIntent(); finish(); startActivity(intent); } } /** * Background Async Task to Load all Announcements by making HTTP Request * */ class LoadAllAnns extends AsyncTask<String, String, String> { /** * Before starting background thread Show Progress Dialog * */ @Override protected void onPreExecute() { super.onPreExecute(); pDialog = new ProgressDialog(AllAnnActivity.this); pDialog.setMessage("Loading details. Please wait..."); pDialog.setIndeterminate(false); pDialog.setCancelable(false); pDialog.show(); } /** * getting All Anns from url * */ @Override protected String doInBackground(String... args) { // Building Parameters List<NameValuePair> params = new ArrayList<NameValuePair>(); // getting JSON string from URL JSONObject json = jParser.makeHttpRequest(url_academic_calendar, "GET", params); // Check your log cat for JSON reponse Log.d("All Anns: ", json.toString()); try { // Checking for SUCCESS TAG int success = json.getInt(TAG_SUCCESS); if (success == 1) { // Getting Array of Anns notices = json.getJSONArray(TAG_ANN); // looping through All Anns for (int i = 0; i < notices.length(); i++) { JSONObject c = notices.getJSONObject(i); // Storing each json item in variable String id = c.getString(TAG_PID); String name = c.getString(TAG_NAME); String info = c.getString(TAG_INFO); //contains the URL String date = c.getString(TAG_DATE); // creating new HashMap HashMap<String, String> map = new HashMap<String, String>(); // Mapping HashMap key => value map.put(TAG_PID, id); map.put(TAG_NAME, name); map.put(TAG_INFO, info); map.put(TAG_DATE, date); // adding HashList to ArrayList AnouncementList.add(map); } } else { /** nothing found * Need to implement an error message if nothing was found. **/ } } catch (JSONException e) { e.printStackTrace(); } return null; } /** * After completing background task Dismiss the progress dialog * **/ @Override protected void onPostExecute(String file_url) { // dismiss the dialog after getting JSON data pDialog.dismiss(); // updating UI from Background Thread runOnUiThread(new Runnable() { @Override public void run() { /** * Updating parsed JSON data into ListView * */ ListAdapter adapter = new SimpleAdapter(AllAnnActivity.this, AnouncementList, R.layout.list_item_ann, new String[] { TAG_PID, TAG_NAME, TAG_INFO, TAG_DATE }, new int[] { R.id.impid, R.id.impame, R.id.impinfo, R.id.impdate }); setListAdapter(adapter); } }); } } @Override protected void onStart() { super.onStart(); EasyTracker.getInstance().activityStart(this); } @Override protected void onStop() { super.onStop(); EasyTracker.getInstance().activityStop(this); } }