Develop Reference

How to Set ImageView in AsyncTask

I understand that we cannot set ImageView in AsyncTask. But I need to add the ImageView into HashMap and the HashMap need to add into an ArrayList inside the for loop. I cannot do that in onPostExecute(). Does anyone know how to do?
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 android.app.ListActivity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Base64;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ImageView;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
public class AllProductsActivity extends ListActivity {
// Progress Dialog
private ProgressDialog pDialog;
// Creating JSON Parser object
JSONParser jParser = new JSONParser();
ArrayList<HashMap<String, String>> productsList;
// url to get all products list
private static String url_all_products = "http://192.168.1.132/retEqp.php";
ImageView iv;
// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_PRODUCTS = "equipments";
private static final String TAG_PID = "item_ID";
private static final String TAG_NAME = "item_Name";
private static final String TAG_DESC = "item_Desc";
private static final String TAG_LOC = "item_Location";
private static final String TAG_STATUS = "item_Status";
private static final String TAG_IMAGE = "item_Image";
// products JSONArray
JSONArray equipments = null;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.all_products);
iv = (ImageView)findViewById(R.id.img2);
// Hashmap for ListView
productsList = new ArrayList<HashMap<String, String>>();
// Loading products in Background Thread
new LoadAllProducts().execute();
// Get listview
ListView lv = getListView();
// on seleting single product
// launching Edit Product Screen
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.pid)).getText()
.toString();
// Starting new intent
Intent previousScreen = new Intent(getApplicationContext(), NewProductActivity.class);
//Sending the data to NewProductActivity
previousScreen.putExtra("id",pid);
setResult(1000, previousScreen);
finish();
// starting new activity and expecting some response back
}
});
}
// Response from Edit Product Activity
#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
// means user edited/deleted product
// reload this screen again
Intent intent = getIntent();
finish();
startActivity(intent);
}
}
/**
* Background Async Task to Load all product by making HTTP Request
* */
class LoadAllProducts extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
#Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(AllProductsActivity.this);
pDialog.setMessage("Loading products. Please wait...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
/**
* getting All products from url
* */
protected String doInBackground(String... args) {
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
// getting JSON string from URL
JSONObject json = jParser.makeHttpRequest(url_all_products, "GET", params);
// Check your log cat for JSON reponse
// Log.d("All Products: ", json.toString());
try {
equipments = json.getJSONArray(TAG_PRODUCTS);
// looping through All Products
for (int i = 0; i < equipments.length(); i++) {
JSONObject c = equipments.getJSONObject(i);
// Storing each json item in variable
String id = "ID: "+c.getString(TAG_PID);
String name = "Name: "+c.getString(TAG_NAME);
String desc = "Description: "+c.getString(TAG_DESC);
String loc = "Location: "+c.getString(TAG_LOC);
String status = "Status: "+c.getString(TAG_STATUS);
String image = c.getString(TAG_IMAGE);
byte[] rawImage = Base64.decode(image, Base64.DEFAULT);
Bitmap bmp12 = BitmapFactory.decodeByteArray(rawImage, 0, rawImage.length);
iv.setImageBitmap(bmp12);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
// map.put(TAG_IMAGE, rawImage.length);
map.put(TAG_PID, id);
map.put(TAG_NAME, name);
map.put(TAG_DESC, desc);
map.put(TAG_LOC, loc);
map.put(TAG_STATUS, status);
map.put(TAG_IMAGE, iv.toString());
// adding HashList to ArrayList
productsList.add(map);
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
/**
* After completing background task Dismiss the progress dialog
* **/
protected void onPostExecute(String file_url) {
// dismiss the dialog after getting all products
pDialog.dismiss();
// updating UI from Background Thread
runOnUiThread(new Runnable() {
public void run() {
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
AllProductsActivity.this, productsList,
R.layout.list_item, new String[] { TAG_IMAGE,TAG_PID,
TAG_NAME,TAG_DESC,TAG_LOC,TAG_STATUS},
new int[] {R.id.img,R.id.pid, R.id.name,R.id.desc,R.id.loc,R.id.status});
// updating listview
setListAdapter(adapter);
}
});
}
}
}

You can't access the UI in a background thread.
The idea behind AsyncTask is that doInBackground does the background work, then you can return something that will be passed as a parameter to onPostExecute which is executed in the main thread.
In this case you have to return the parsed model objects from doInBackground (I would create a custom class), receive in onPostExecute. Also, create a custom adapter, which will take care of creating views. You should generate bitmaps there (probably you have to put the parsing to bitmap in another async task).

JSON Parsed Data not showing in ListFragment

I have used a MYSQL Database and connected it to my Android App using PHP. I added a sample row in the table and the PHP Script is returning JSON. I have tried my best in parsing the JSON and displaying it in a list. But it does not seem to be working. Able to run the App - But does not display content - Only shows the Dialog. It seems to work in Case of an Activity - What changes should be made to make it work for a Fragment. Here is my LogCat when I open up the fragment - http://prntscr.com/3f6k0a .
package com.example.socbeta;
import java.util.ArrayList;
import java.util.HashMap;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.ListFragment;
import android.app.ProgressDialog;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
public class events extends ListFragment {
private ProgressDialog pDialog;
private static final String READ_EVENTS_URL ="http://socapptest.comoj.com/socbeta/events.php";
//JSON IDS:
private static final String TAG_SUCCESS = "success";
private static final String TAG_EventName = "EventName";
private static final String TAG_POSTS = "posts";
private static final String TAG_ID = "ID";
private static final String TAG_DATE = "Date";
private static final String TAG_MESSAGE = "message";
private JSONArray mEvents = null;
private ArrayList<HashMap<String, String>> mEventList;
public events(){}
#Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
return inflater.inflate(R.layout.events, container, false);
}
#Override
public void onResume() {
// TODO Auto-generated method stub
super.onResume();
//loading the comments via AsyncTask
new LoadEvents().execute();
}
public void updateJSONdata() {
mEventList = new ArrayList<HashMap<String, String>>();
JSONParser jParser = new JSONParser();
JSONObject json = jParser.getJSONFromUrl(READ_EVENTS_URL);
try {
mEvents = json.getJSONArray(TAG_POSTS);
for (int i = 0; i < mEvents.length(); i++) {
JSONObject c = mEvents.getJSONObject(i);
String EventName = c.getString(TAG_EventName);
String content = c.getString(TAG_MESSAGE);
String Date = c.getString(TAG_DATE);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
map.put(TAG_EventName, EventName);
map.put(TAG_MESSAGE, content);
map.put(TAG_DATE, Date);
mEventList.add(map);
}
} catch (JSONException e) {
e.printStackTrace();
}
}
private void updateList() {
ListAdapter adapter = new SimpleAdapter(getActivity(), mEventList,
R.layout.list_item,
new String[] { TAG_EventName, TAG_MESSAGE,TAG_DATE },
new int[] { R.id.eventname, R.id.message,R.id.date });
setListAdapter(adapter);
ListView lv = getListView();
lv.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
});
}
public class LoadEvents extends AsyncTask<Void, Void, Boolean> {
#Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(getActivity());
pDialog.setMessage("Loading Events...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
}
#Override
protected Boolean doInBackground(Void... arg0) {
updateJSONdata();
return null;
}
#Override
protected void onPostExecute(Boolean result) {
super.onPostExecute(result);
pDialog.dismiss();
updateList();
}
}
}
EDIT :
Got my code to work. The Problem was with the JSON Structure. I did not Navigate properly and this gave me a "No Value for message" Error. For others who might be having same issues - Remember that when you have { in your JSON , you use JSONArray and when you have [ you use JSONObject. You need to navigate module wise through your JSON.

try this code
pass json string to this method . it will work
public JSONObject getJSONfromURL(String url)
{
InputStream is = null;
JSONObject jObj = null;
String json = "";
try {
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpGet httpget= new HttpGet(url);
HttpResponse httpResponse = httpClient.execute(httpget);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
} catch (Exception e) {
e.printStackTrace();
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(is, "UTF-8"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
json = sb.toString();
} catch (Exception e) {
}
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
return jObj;
}

How to check weather JsonArray value available or not in android from webservice and get its data?

I am working on learning JsonParsing. In that I have some category_list array. I parse data from that array and bind it to a listView in android. From that list I also again have to make an API call to that Web-service and check that sub-category are there or not ? If there is no sub category then it will be product list. i have tried as below but i have unable to parse from productList json
How to decide or give me any solution logic for it. My code is as below:
main.java
package com.epe.yehki.ui;
import java.util.ArrayList;
import java.util.HashMap;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import com.epe.yehki.backend.ServiceHandler;
import com.epe.yehki.uc.Header;
import com.example.yehki.R;
import android.R.string;
import android.app.Activity;
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.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
import android.widget.AdapterView.OnItemClickListener;
public class SubCategoryActivity extends ListActivity {
// SUB CATEGORIES...
private static final String TAG_CAT_LlIS = "categories_list";
private static final String TAG_CAT_ID = "category_id";
private static final String TAG_CAT_NAME = "category_name";
int flag;
public Header header;
public TextView title;
// PRODUCTS....
private static final String TAG_PRODUCT_ID = "product_id";
private static final String TAG_PRODUCT_LlST = "product_list";
private static final String TAG_PRODUCT_NAME = "product_name";
private static final String TAG_PRODUCT_IMG = "image";
private static final String TAG_PRODUCT_DESCRIPTION = "detail_description";
// contacts JSONArray
JSONArray subcategories = null;
JSONArray products = null;
public String catid;
public String id;
String name;
JSONObject jsonObj;
// Hashmap for ListView
ArrayList<HashMap<String, String>> subcategoryList;
ArrayList<HashMap<String, String>> productList;
private ProgressDialog pDialog;
// URL to get contacts JSON
private static String url = "http://yehki.epagestore.in/app_api/categories.php";
private static String mainurl = "http://yehki.epagestore.in/";
public String suburl = "";
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_sub);
this.header = (Header) findViewById(R.id.headersubcat);
title = (TextView) findViewById(R.id.title);
// getting intent data
Intent in = getIntent();
// Get JSON values from previous intent
try {
catid = in.getStringExtra(TAG_CAT_ID);
name = in.getStringExtra(TAG_CAT_NAME);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println("::::::::::::::MY CATEGORY ID::::::::::::::IN SUB "
+ catid);
subcategoryList = new ArrayList<HashMap<String, String>>();
suburl = "http://yehki.epagestore.in/app_api/categories.php?"
+ TAG_CAT_ID + "=" + catid;
System.out.println("::::::::::::::::MY SUBCATEGORY URL::::::::::::"
+ suburl);
title.setText(name);
// Displaying all values on the screen
ListView lv = getListView();
new GetSubCategories().execute();
// Listview on item click listener
lv.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String catname = ((TextView) view.findViewById(R.id.name))
.getText().toString();
Intent in = new Intent(getApplicationContext(),
SubCategoryTwoActivity.class);
in.putExtra(TAG_CAT_NAME, catname);
in.putExtra(TAG_CAT_ID, catid);
startActivity(in);
}
});
}
private class GetSubCategories extends AsyncTask<Void, Void, Void> {
#Override
protected void onPreExecute() {
super.onPreExecute();
// Showing progress dialog
pDialog = new ProgressDialog(SubCategoryActivity.this);
pDialog.setMessage("Please wait...");
pDialog.setCancelable(false);
pDialog.show();
}
#Override
protected Void doInBackground(Void... arg0) {
// Creating service handler class instance
ServiceHandler sh = new ServiceHandler();
System.out.println(":::::::::::::::::::SUB URL:::::::::::::::::"
+ suburl);
// Making a request to url and getting response
String jsonStr = sh.makeServiceCall(suburl, ServiceHandler.GET);
Log.d("Response: ", "> " + jsonStr);
if (jsonStr != null) {
try {
jsonObj = new JSONObject(jsonStr);
// Getting JSON Array node
if (jsonObj.has(TAG_CAT_LlIS)) {
subcategories = jsonObj.getJSONArray(TAG_CAT_LlIS);
if (subcategories != null
&& subcategories.length() != 0) {
// looping through All Contacts
flag = 0;
System.out
.println(":::::::::::FLAG IN SUB:::::::::::"
+ subcategories.length());
for (int i = 0; i < subcategories.length(); i++) {
JSONObject c = subcategories.getJSONObject(i);
id = c.getString(TAG_CAT_ID);
String name = c.getString(TAG_CAT_NAME);
// tmp hashmap for single category
HashMap<String, String> subcategory = new HashMap<String, String>();
// adding each child node to HashMap key =>
// value
subcategory.put(TAG_CAT_ID, id);
subcategory.put(TAG_CAT_NAME, name);
// adding contact to contact list
subcategoryList.add(subcategory);
}
}
} else {
flag = 1;
products = jsonObj.getJSONArray(TAG_PRODUCT_LlST);
System.out
.println("==========SIZE OF MY ARRAY PRODUCT LIST==================="
+ products.length());
System.out
.println(":::::::::::::::::::Product array:::::::::::::::"
+ products);
// looping through All Contacts
for (int i = 0; i < products.length(); i++) {
JSONObject p = products.getJSONObject(i);
String proId = p.getString(TAG_PRODUCT_ID);
String proName = p.getString(TAG_PRODUCT_NAME);
String productImg = p.getString(TAG_PRODUCT_IMG);
String productDesc = p
.getString(TAG_PRODUCT_DESCRIPTION);
System.out
.println("::::::::::::::::MY PRODUCT DETAILS::::::::::::::"
+ TAG_PRODUCT_ID
+ " PRODUCT NAME "
+ TAG_PRODUCT_NAME
+ " PRODUCT_DESCRIPTION "
+ TAG_PRODUCT_DESCRIPTION
+ " PRODUCT IMAGE "
+ TAG_PRODUCT_IMG);
HashMap<String, String> product = new HashMap<String, String>();
// adding each child node to HashMap key => value
// product.put(TAG_PRODUCT_ID, proId);
product.put(TAG_PRODUCT_NAME, proName);
product.put(TAG_PRODUCT_DESCRIPTION, productDesc);
/*
* product.put(TAG_PRODUCT_IMG, productImg);
*/
productList.add(product);
}
}
} catch (JSONException e) {
e.printStackTrace();
}
} else {
Log.e("ServiceHandler", "Couldn't get any data from the url");
}
return null;
}
#Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
// Dismiss the progress dialog
if (pDialog.isShowing())
pDialog.dismiss();
/**
* Updating parsed JSON data into ListView
*
* */
if (flag == 0) {
ListAdapter adapter = new SimpleAdapter(
SubCategoryActivity.this, subcategoryList,
R.layout.list_item, new String[] { TAG_CAT_NAME },
new int[] { R.id.name });
setListAdapter(adapter);
} else {
ListAdapter adapter = new SimpleAdapter(
SubCategoryActivity.this, subcategoryList,
R.layout.activity_single_produt, new String[] {
TAG_PRODUCT_NAME, TAG_PRODUCT_DESCRIPTION,
TAG_PRODUCT_IMG }, new int[] {
R.id.product_label, R.id.product_desc,
R.id.iv_product_img });
setListAdapter(adapter);
}
}
}
}

try this:
if(jsonObj.has("name_of_the_field")){
//yes
}
or
JSONArray mJSONArray = jsonObj.optJSONArray("name of array");
the method optJSONArray("nameofarray") will return a null JSONArray if it could not find the JSONArray with provided name.

hmm there is one method to check if the key exists or not in json.
like if you have json array and you want to check if there is subcategory than
call method on that array object.

The JSONObject has method to check if the key exists in the JSON or not.
Quoting from the docs.
public boolean has (String name)
//Returns true if this object has a mapping for name. The mapping may be NULL.
You can find the official doc here

List view activity showing objects only the first time it is opened

In my Android app I have a list view activity showing MySQL objects downloaded from a web server via JSON.
I have detected following issue: the first time the activity is shown, the JSON objects are shown fine, but if the user goes back to the previous activity and then opens the list view activity again, any object is shown on the list and no error is thrown.
I need your help to solve this issue. Here is the activity code:
import java.util.ArrayList;
import java.util.HashMap;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
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 ofertas_list extends ListActivity {
private ProgressDialog pDialog;
// JSON node keys
private static final String TAG_NAME = "nombreCategoria";
private static final String TAG_ID = "idCategoria";
private static final String TAG_CATEGORIAS = "Categorias";
// URL to get contacts JSON
private static String url = "http://xxxxxxxx/android_ofertaslist.php?id=";
// JSON Node names
private static final String TAG_NOMBREEMPRESA = "nombreEmpresa";
private static final String TAG_IDEMPRESA = "idEmpresa";
private static final String TAG_DESCRIPCIONEMPRESA = "descripcionEmpresa";
private static final String TAG_STRIMAGEN = "strImagen";
private static final String TAG_DIRECCIONEMPRESA = "direccionEmpresa";
private static final String TAG_TELEFONOEMPRESA = "telefonoEmpresa";
private static final String TAG_FACEBOOKEMPRESA = "facebookEmpresa";
private static final String TAG_EMAILEMPRESA = "emailEmpresa";
private static final String TAG_TEXTOOFERTA = "textoOferta";
private static final String TAG_HORARIOEMPRESA = "horarioEmpresa";
private static final String TAG_CATEGORIAEMPRESA = "categoriaEmpresa";
private static final String TAG_LATITUDEMPRESA = "latitudEmpresa";
private static final String TAG_LONGITUDEMPRESA = "longitudEmpresa";
private static final String TAG_VALORACIONEMPRESA = "valoracionEmpresa";
// contacts JSONArray
JSONArray contacts = null;
// Hashmap for ListView
ArrayList<HashMap<String, String>> contactList;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_categorias);
// getting intent data
Intent in = getIntent();
// JSON node keys
// Get JSON values from previous intent
String name = in.getStringExtra(TAG_NAME);
String email = in.getStringExtra(TAG_ID);
// URL to get contacts JSON
this.url = url+email;
this.setTitle(name);
contactList = new ArrayList<HashMap<String, String>>();
ListView lv = getListView();
// Listview on item click listener
lv.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
//cambiar por los nuevos campos
String name = ((TextView) view.findViewById(R.id.name))
.getText().toString();
String cost = ((TextView) view.findViewById(R.id.email))
.getText().toString();
//Starting single contact activity
//cambiar por los nuevos campos
Intent in = new Intent(getApplicationContext(),
SingleContactActivity.class);
in.putExtra(TAG_NAME, name);
in.putExtra(TAG_ID, cost);
startActivity(in);
}
});
// Calling async task to get json
new GetContacts().execute();
}
/**
* Async task class to get json by making HTTP call
* */
private class GetContacts extends AsyncTask<Void, Void, Void> {
#Override
protected void onPreExecute() {
super.onPreExecute();
// Showing progress dialog
pDialog = new ProgressDialog(ofertas_list.this);
pDialog.setMessage("Cargando datos...");
pDialog.setCancelable(false);
pDialog.show();
}
#Override
protected Void doInBackground(Void... arg0) {
// Creating service handler class instance
ServiceHandler sh = new ServiceHandler();
// Making a request to url and getting response
String jsonStr = sh.makeServiceCall(url, ServiceHandler.GET);
Log.d("Response: ", "> " + jsonStr);
if (jsonStr != null) {
try {
JSONObject jsonObj = new JSONObject(jsonStr);
// Getting JSON Array node
contacts = jsonObj.getJSONArray(TAG_CATEGORIAS);
// looping through All Contacts
for (int i = 0; i < contacts.length(); i++) {
JSONObject c = contacts.getJSONObject(i);
String nombreEmpresa = c.getString(TAG_NOMBREEMPRESA);
String descripcionEmpresa = c.getString(TAG_DESCRIPCIONEMPRESA);
String strImagen = c.getString(TAG_STRIMAGEN);
String direccionEmpresa = c.getString(TAG_DIRECCIONEMPRESA);
String telefonoEmpresa = c.getString(TAG_TELEFONOEMPRESA);
String facebookEmpresa = c.getString(TAG_FACEBOOKEMPRESA);
String emailEmpresa = c.getString(TAG_EMAILEMPRESA);
String textoOferta = c.getString(TAG_TEXTOOFERTA);
String horarioEmpresa = c.getString(TAG_HORARIOEMPRESA);
String categoriaEmpresa = c.getString(TAG_CATEGORIAEMPRESA);
String valoracionEmpresa = c.getString(TAG_VALORACIONEMPRESA);
String latitudEmpresa = c.getString(TAG_LATITUDEMPRESA);
String longitudEmpresa = c.getString(TAG_LONGITUDEMPRESA);
String idEmpresa = c.getString(TAG_IDEMPRESA);
// Phone node is JSON Object
// tmp hashmap for single contact
HashMap<String, String> contact = new HashMap<String, String>();
// adding each child node to HashMap key => value
contact.put(TAG_IDEMPRESA, idEmpresa);
contact.put(TAG_NOMBREEMPRESA, nombreEmpresa);
contact.put(TAG_DESCRIPCIONEMPRESA,descripcionEmpresa);
contact.put(TAG_STRIMAGEN,strImagen);
contact.put(TAG_DIRECCIONEMPRESA,direccionEmpresa);
contact.put(TAG_TELEFONOEMPRESA,telefonoEmpresa);
contact.put(TAG_FACEBOOKEMPRESA,facebookEmpresa);
contact.put(TAG_EMAILEMPRESA,emailEmpresa);
contact.put(TAG_TEXTOOFERTA,textoOferta);
contact.put(TAG_HORARIOEMPRESA,horarioEmpresa);
contact.put(TAG_CATEGORIAEMPRESA,categoriaEmpresa);
contact.put(TAG_VALORACIONEMPRESA,valoracionEmpresa);
contact.put(TAG_LATITUDEMPRESA,latitudEmpresa);
contact.put(TAG_LONGITUDEMPRESA,longitudEmpresa);
// adding contact to contact list
contactList.add(contact);
}
} catch (JSONException e) {
e.printStackTrace();
}
} else {
Log.e("ServiceHandler", "Couldn't get any data from the url");
}
return null;
}
#Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
// Dismiss the progress dialog
if (pDialog.isShowing())
pDialog.dismiss();
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
ofertas_list.this, contactList,
R.layout.list_item_ofertas, new String[] { TAG_NOMBREEMPRESA, TAG_DIRECCIONEMPRESA}, new int[] { R.id.name,
R.id.email });
setListAdapter(adapter);
}
}
}
UPDATED CODE:
import java.util.ArrayList;
import java.util.HashMap;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
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 ofertas_list extends ListActivity {
private ProgressDialog pDialog;
// JSON node keys
private static final String TAG_NAME = "nombreCategoria";
private static final String TAG_ID = "idCategoria";
private static final String TAG_CATEGORIAS = "Categorias";
// URL to get contacts JSON
private static String url = "http://xxxxxxx/android_ofertaslist.php?id=";
// URL to get contacts JSON
// private static String url = "http://mujercanariasigloxxi.appgestion.eu/app_php_files/android_ofertaslist.php";
// JSON Node names
private static final String TAG_NOMBREEMPRESA = "nombreEmpresa";
private static final String TAG_IDEMPRESA = "idEmpresa";
private static final String TAG_DESCRIPCIONEMPRESA = "descripcionEmpresa";
private static final String TAG_STRIMAGEN = "strImagen";
private static final String TAG_DIRECCIONEMPRESA = "direccionEmpresa";
private static final String TAG_TELEFONOEMPRESA = "telefonoEmpresa";
private static final String TAG_FACEBOOKEMPRESA = "facebookEmpresa";
private static final String TAG_EMAILEMPRESA = "emailEmpresa";
private static final String TAG_TEXTOOFERTA = "textoOferta";
private static final String TAG_HORARIOEMPRESA = "horarioEmpresa";
private static final String TAG_CATEGORIAEMPRESA = "categoriaEmpresa";
private static final String TAG_LATITUDEMPRESA = "latitudEmpresa";
private static final String TAG_LONGITUDEMPRESA = "longitudEmpresa";
private static final String TAG_VALORACIONEMPRESA = "valoracionEmpresa";
#Override
public void onResume(){
super.onResume();
new GetContacts().execute();
}
// contacts JSONArray
JSONArray contacts = null;
// Hashmap for ListView
ArrayList<HashMap<String, String>> contactList;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_categorias);
// getting intent data
Intent in = getIntent();
// JSON node keys
// Get JSON values from previous intent
String name = in.getStringExtra(TAG_NAME);
String email = in.getStringExtra(TAG_ID);
// URL to get contacts JSON
this.url = url+email;
this.setTitle(name);
contactList = new ArrayList<HashMap<String, String>>();
ListView lv = getListView();
// Listview on item click listener
lv.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
//cambiar por los nuevos campos
String name = ((TextView) view.findViewById(R.id.name))
.getText().toString();
String cost = ((TextView) view.findViewById(R.id.email))
.getText().toString();
//Starting single contact activity
//cambiar por los nuevos campos
Intent in = new Intent(getApplicationContext(),
SingleContactActivity.class);
in.putExtra(TAG_NAME, name);
in.putExtra(TAG_ID, cost);
startActivity(in);
}
});
// Calling async task to get json
new GetContacts().execute();
}
/**
* Async task class to get json by making HTTP call
* */
private class GetContacts extends AsyncTask<Void, Void, Void> {
#Override
protected void onPreExecute() {
super.onPreExecute();
// Showing progress dialog
pDialog = new ProgressDialog(ofertas_list.this);
pDialog.setMessage("Cargando datos...");
pDialog.setCancelable(false);
pDialog.show();
}
#Override
protected Void doInBackground(Void... arg0) {
// Creating service handler class instance
ServiceHandler sh = new ServiceHandler();
// Making a request to url and getting response
String jsonStr = sh.makeServiceCall(url, ServiceHandler.GET);
Log.d("Response: ", "> " + jsonStr);
if (jsonStr != null) {
try {
JSONObject jsonObj = new JSONObject(jsonStr);
// Getting JSON Array node
contacts = jsonObj.getJSONArray(TAG_CATEGORIAS);
// looping through All Contacts
for (int i = 0; i < contacts.length(); i++) {
JSONObject c = contacts.getJSONObject(i);
String nombreEmpresa = c.getString(TAG_NOMBREEMPRESA);
String descripcionEmpresa = c.getString(TAG_DESCRIPCIONEMPRESA);
String strImagen = c.getString(TAG_STRIMAGEN);
String direccionEmpresa = c.getString(TAG_DIRECCIONEMPRESA);
String telefonoEmpresa = c.getString(TAG_TELEFONOEMPRESA);
String facebookEmpresa = c.getString(TAG_FACEBOOKEMPRESA);
String emailEmpresa = c.getString(TAG_EMAILEMPRESA);
String textoOferta = c.getString(TAG_TEXTOOFERTA);
String horarioEmpresa = c.getString(TAG_HORARIOEMPRESA);
String categoriaEmpresa = c.getString(TAG_CATEGORIAEMPRESA);
String valoracionEmpresa = c.getString(TAG_VALORACIONEMPRESA);
String latitudEmpresa = c.getString(TAG_LATITUDEMPRESA);
String longitudEmpresa = c.getString(TAG_LONGITUDEMPRESA);
String idEmpresa = c.getString(TAG_IDEMPRESA);
// Phone node is JSON Object
// tmp hashmap for single contact
HashMap<String, String> contact = new HashMap<String, String>();
// adding each child node to HashMap key => value
contact.put(TAG_IDEMPRESA, idEmpresa);
contact.put(TAG_NOMBREEMPRESA, nombreEmpresa);
contact.put(TAG_DESCRIPCIONEMPRESA,descripcionEmpresa);
contact.put(TAG_STRIMAGEN,strImagen);
contact.put(TAG_DIRECCIONEMPRESA,direccionEmpresa);
contact.put(TAG_TELEFONOEMPRESA,telefonoEmpresa);
contact.put(TAG_FACEBOOKEMPRESA,facebookEmpresa);
contact.put(TAG_EMAILEMPRESA,emailEmpresa);
contact.put(TAG_TEXTOOFERTA,textoOferta);
contact.put(TAG_HORARIOEMPRESA,horarioEmpresa);
contact.put(TAG_CATEGORIAEMPRESA,categoriaEmpresa);
contact.put(TAG_VALORACIONEMPRESA,valoracionEmpresa);
contact.put(TAG_LATITUDEMPRESA,latitudEmpresa);
contact.put(TAG_LONGITUDEMPRESA,longitudEmpresa);
// adding contact to contact list
contactList.add(contact);
}
} catch (JSONException e) {
e.printStackTrace();
}
} else {
Log.e("ServiceHandler", "Couldn't get any data from the url");
}
return null;
}
#Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
// Dismiss the progress dialog
if (pDialog.isShowing())
pDialog.dismiss();
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
ofertas_list.this, contactList,
R.layout.list_item_ofertas, new String[] { TAG_NOMBREEMPRESA, TAG_DIRECCIONEMPRESA}, new int[] { R.id.name,
R.id.email });
setListAdapter(adapter);
}
}
}

You should probably perform the "new GetContacts().execute();" call in onResume(). See the Android documentation to get more familiar with the Android Activity lifecyle.
onCreate() is only called when the Activity is created. In your testing, the Activity is probably usually still alive, so onCreate() will not always be called when re-entering the Activity.

Put your new GetContacts().execute() in onResume() method.
onCreate() is called when you start Activity for the first time. If you leave activity, without killing it, and come back, your app goes thru onStart() ->onResume()`
Put onResume right before onCreate and remove new GetContacts().execute(); from onCreate().
...
// Hashmap for ListView
ArrayList<HashMap<String, String>> contactList;
#Override
public void onResume(){
super.onResume();
new GetContacts().execute();
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_categorias);
...

My aSyncTask is not working

my asynctask is not working. The dialog wont dismiss and the list is not being updated (i think because onPostExecute is not being called).I googled it, but without result.
package com.example.whs;
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 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.Menu;
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;
public class Albums extends ListActivity {
// Progress Dialog
private ProgressDialog pDialog;
// Creating JSON Parser object
JSONParser jParser = new JSONParser();
// Array for the list
ArrayList<HashMap<String, String>> itemList;
// url to get the items
private static String url_all_products = "<my url here>";
// JSON variables
private static final String TAG_SUCCESS = "success";
private static final String TAG_MESSAGE = "message";
private static final String TAG_ITEMS = "items";
private static final String TAG_NAME = "name";
private static final String TAG_ID = "id";
private static final String TAG_USERNAME = "username";
//JSON array
JSONArray items = null;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_albums);
// HashMap for the items
itemList = new ArrayList<HashMap<String, String>>();
// Loading the items on the background
new LoadAllItems().execute();
// Get list-view
ListView lv = getListView();
// On item click
lv.setOnItemClickListener(new OnItemClickListener(){
public void onItemClick(AdapterView<?> parent, View view, int position, long id){
//do
}
});
}
// class for loading all items
class LoadAllItems extends AsyncTask<String, String, String> {
// Before
#Override
protected void onPreExecute(){
super.onPreExecute();
pDialog = new ProgressDialog(Albums.this);
pDialog.setMessage("Albums laden...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
// Get the products
#Override
protected String doInBackground(String... params) {
// Build Parameters
List<NameValuePair> params1 = new ArrayList<NameValuePair>();
//Get the JSON string
JSONObject json = jParser.makeHttpRequest(url_all_products, "GET", params1);
// Check for response
Log.d("All Items: ", json.toString());
try {
// check for success tag
int success = json.getInt(TAG_SUCCESS);
if(success == 1) {
// found the items
items = json.getJSONArray(TAG_ITEMS);
// loop through the items
for (int i = 0; items.length() > i; i++){
// Get the item in variable c
JSONObject c = items.getJSONObject(i);
// Store in a variable
String id = c.getString(TAG_ID);
String name = c.getString(TAG_NAME);
String username = c.getString(TAG_USERNAME);
if(username == ""){
username = "onbekend";
}
// Create the HashMap
HashMap<String, String> map = new HashMap<String, String>();
// add it
map.put(TAG_ID, id);
map.put(TAG_USERNAME, username);
map.put(TAG_NAME, name);
// to arraylist
itemList.add(map);
}
}else{
// nothing found
Intent i = new Intent(getApplicationContext(), Index.class);
// close the previous activities
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(i);
}
} catch (JSONException e){
e.printStackTrace();
}
return null;
}
}
protected void onPostExecute(String result){
// dismiss dialog
pDialog.dismiss();
runOnUiThread(new Runnable(){
public void run(){
// Add adapter to the list
MenuAdapter adapter = new MenuAdapter(Albums.this, itemList);
ListView list = (ListView)findViewById(R.id.list);
list.setAdapter(adapter);
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.albums, menu);
return true;
}
}
the loop is working correctly.
How to fix this?

1) you are trying to start an activity within the background thread, don't do this.
2) you are probably getting a json exception, just log more things so you can see what is happening
these may be why it never reaches onPostExecute

you can not perform UI related action in doInBackGround(), like you are strating a new activity in doInBaclground,
Intent i = new Intent(getApplicationContext(), Index.class);
// close the previous activities
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(i);