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Android Get data from server to android issue

I want to get data from server and save it in the listview I have write right code there is no error but when I click on activity app stopped here is my activity code/
public class UserListActivity extends ActionBarActivity {
String myJSON;
private static final String TAG_RESULTS="result";
// private static final String TAG_ID = "id";
private static final String TAG_NAME = "name";
private static final String TAG_EMAIL ="email";
JSONArray peoples = null;
ArrayList<HashMap<String, String>> personList;
ListView list;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_user_list);
list = (ListView) findViewById(R.id.listView);
personList = new ArrayList<HashMap<String,String>>();
getData();
}
protected void showList(){
try {
JSONObject jsonObj = new JSONObject(myJSON);
peoples = jsonObj.getJSONArray(TAG_RESULTS);
for(int i=0;i<peoples.length();i++){
JSONObject c = peoples.getJSONObject(i);
//String id = c.getString(TAG_ID);
String name = c.getString(TAG_NAME);
String email = c.getString(TAG_EMAIL);
HashMap<String,String> users = new HashMap<String,String>();
// persons.put(TAG_ID,id);
users.put(TAG_NAME,name);
users.put(TAG_EMAIL,email);
personList.add(users);
}
ListAdapter adapter = new SimpleAdapter(
UserListActivity.this, personList, R.layout.list_item,
new String[]{TAG_NAME,TAG_EMAIL},
new int[]{R.id.name, R.id.email}
);
list.setAdapter(adapter);
} catch (JSONException e) {
e.printStackTrace();
}
}
public void getData(){
class GetDataJSON extends AsyncTask<String, Void, String>{
#Override
protected String doInBackground(String... params) {
DefaultHttpClient httpclient = new DefaultHttpClient(new BasicHttpParams());
HttpPost httppost = new HttpPost("http://samplechatapp.gear.host/Get-Data.php");
// Depends on your web service
httppost.setHeader("Content-type", "application/json");
InputStream inputStream = null;
String result = null;
try {
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
inputStream = entity.getContent();
// json is UTF-8 by default
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream, "UTF-8"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null)
{
sb.append(line + "\n");
}
result = sb.toString();
} catch (Exception e) {
// Oops
}
finally {
try{if(inputStream != null)inputStream.close();}catch(Exception squish){}
}
return result;
}
#Override
protected void onPostExecute(String result){
myJSON=result;
showList();
}
}
GetDataJSON g = new GetDataJSON();
g.execute();
}
}
This is log cat message:
This is the data on the server which I want to get.

Android Json Parse returns nothing

I have a Json Parser Class which looks like this:
public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
public JSONParser() {
}
// function get json from url
// by making HTTP POST or GET mehtod
public JSONObject makeHttpRequest(String url, String method,
List<NameValuePair> params) {
// Making HTTP request
try {
// check for request method
if(method == "POST"){
// request method is POST
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
httpPost.setEntity(new UrlEncodedFormEntity(params));
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
}else if(method == "GET"){
// request method is GET
DefaultHttpClient httpClient = new DefaultHttpClient();
String paramString = URLEncodedUtils.format(params, "utf-8");
url += "" + paramString;
HttpGet httpGet = new HttpGet(url);
HttpResponse httpResponse = httpClient.execute(httpGet);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
}
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 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) {
Log.e("Buffer Error", "Error converting result " + e.toString());
}
// try parse the string to a JSON object
try {
JSONArray jObj = new JSONArray(json);
System.out.println(jObj.toString());
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
// return JSON String
return jObj;
}
}
Near the end at the last try and catch statement I print out the jsonObject as a string I correctly get the data in the console, the json looks like this:
[{"id":1,"name":"Blooper","description":"Blooper","video_url":"Blooper","platform":1100110011,"logo":"","avaible":0,"token":"","created_at":"2016-04-03
17:19:49","updated_at":"2016-04-03
17:19:49","release_at":"2016-05-08"},{"id":2,"name":"Blooper","description":"Blooper","video_url":"Blooper","platform":"11000000000","logo":"","avaible":0,"token":"","created_at":"2016-04-03
17:26:13","updated_at":"2016-04-03
17:26:13","release_at":"2016-05-08"}]
I used a validator and it is fine.
In my AllProducts activity I try to display that inside the android app.
It looks like this:
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://192.168.155.27:8000/index";
// JSON Node names
private static final String TAG_SUCCESS = "id";
private static final String TAG_PRODUCTS = "name";
private static final String TAG_PID = "description";
private static final String TAG_NAME = "video_url";
// products JSONArray
JSONArray products = null;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.all_products);
// 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 in = new Intent(getApplicationContext(),
EditProductActivity.class);
// sending pid to next activity
in.putExtra(TAG_PID, pid);
// starting new activity and expecting some response back
startActivityForResult(in, 100);
}
});
}
// 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) {
// updating UI from Background Thread
runOnUiThread(new Runnable() {
public void run() {
// 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 {
// Checking for SUCCESS TAG
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// products found
// Getting Array of Products
products = json.getJSONArray(TAG_PRODUCTS);
// looping through All Products
for (int i = 0; i < products.length(); i++) {
JSONObject c = products.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(TAG_PID);
String name = c.getString(TAG_NAME);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_PID, id);
map.put(TAG_NAME, name);
// adding HashList to ArrayList
productsList.add(map);
}
} else {
// no products found
// Launch Add New product Activity
Intent i = new Intent(getApplicationContext(),
NewProductActivity.class);
// Closing all previous activities
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(i);
}
} 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_PID,
TAG_NAME},
new int[] { R.id.pid, R.id.name });
// updating listview
setListAdapter(adapter);
}
});
}
}
}
If I try to print out this json:
JSONObject json = new JSONObject();
I get no values (null), so my view keeps being empty.
I get follwing error message:
java.lang.NullPointerException: Attempt to invoke virtual method
'java.lang.String org.json.JSONObject.toString()' on a null object
reference
at
com.example.androidhive.AllProductsActivity$LoadAllProducts$1.run(AllProductsActivity.java:150)
Line 150 is this :
Log.d("All Products: ", json.toString());
Thus Android Studio tells my that
jObj
here, in my jsonparser:
try {
JSONArray jObj = new JSONArray(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
is never used.
http://www.androidhive.info/2012/05/how-to-connect-android-with-php-mysql/
I am not really experienced with this so I really hope for some help, thanks.

With JSONObject json = new JSONObject(); you are creating an empty JSONObject,
the JSONObject returned by jParser.makeHttpRequest(url_all_products, "GET", params); is never used.
You have to do it like this:
JSONObject json = jParser.makeHttpRequest(url_all_products, "GET", params);
so your JSONObject from the JParser will be stored in json.

How to parse this Json Array in android

I have a jsonArray which I want to parse in my android app.
The array:-
[
{
"id": 96905,
"category": "topup",
"detail": "Full talktime of Rs.55 + 1 local airtel SMS free for 1 day",
"price": 55,
"keywords": "topup",
"updated": "2016-01-07 00:16:23.0",
"validity": "7 days",
"service": "Airtel",
"sourceUri": "https://pay.airtel.com/online-payments/recharge.jsp",
"circle": "Assam",
"talktime": 55
},
{
"id": 90397,
"category": "topup",
"price": 510,
"keywords": "topup",
"updated": "2016-01-07 00:16:23.0",
"service": "Airtel",
"sourceUri": "https://pay.airtel.com/online-payments/recharge.jsp",
"circle": "Assam",
"talktime": 520
},
{
"id": 90399,
"category": "topup",
"price": 1000,
"keywords": "topup",
"updated": "2016-01-07 00:16:23.0",
"service": "Airtel",
"sourceUri": "https://pay.airtel.com/online-payments/recharge.jsp",
"circle": "Assam",
"talktime": 1020
}]
My android Code:-
Asynctask:-
private class DownloadJSON extends AsyncTask<Void, Void, Void> {
#Override
protected void onPreExecute() {
super.onPreExecute();
mProgressDialog = new ProgressDialog(MainActivity.this);
mProgressDialog.setTitle("Android JSON Parse Tutorial");
mProgressDialog.setMessage("Loading...");
mProgressDialog.setIndeterminate(false);
mProgressDialog.show();
}
#Override
protected Void doInBackground(Void... params) {
// Create an array
arraylist = new ArrayList<HashMap<String, String>>();
try {
JSONObject jo;
JSONArray ja2 = JSONfunctions.getJSONfromURL("http://app.ireff.in:9090/IreffWeb/android?service=airtel&circle=assam");
for (int i = 0; i < ja2.length(); i++) {
HashMap<String, String> map = new HashMap<String, String>();
jo = ja2.getJSONObject(i);
map.put("rank", jo.getString("price"));
map.put("country", jo.getString("validity"));
map.put("population", jo.getString("talktime"));
arraylist.add(map);
}
} catch (JSONException e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(Void args) {
listview = (ListView) findViewById(R.id.listview);
adapter = new ListViewAdapter(MainActivity.this, arraylist);
listview.setAdapter(adapter);
mProgressDialog.dismiss();
}
}
JsonFunctions.java
public class JSONfunctions {
public static JSONArray getJSONfromURL(String url) {
InputStream is = null;
String result = "";
JSONArray jArray = null;
// Download JSON data from URL
try {
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(url);
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
} catch (Exception e) {
Log.e("log_tag", "Error in http connection " + e.toString());
}
// Convert response to string
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
result = sb.toString();
} catch (Exception e) {
Log.e("log_tag", "Error converting result " + e.toString());
}
try {
jArray = new JSONArray(result);
} catch (JSONException e) {
Log.e("log_tag", "Error parsing data " + e.toString());
}
return jArray;
}
}
The error I get:-
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'int org.json.JSONArray.length()' on a null object reference
at com.androidbegin.jsonparsetutorial.MainActivity$DownloadJSON.doInBackground(MainActivity.java:67)
at com.androidbegin.jsonparsetutorial.MainActivity$DownloadJSON.doInBackground(MainActivity.java:39)
at android.os.AsyncTask$2.call(AsyncTask.java:292)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:818)
The json is hosted here
I was following this tutorial for learning json parsing, but this tutorial uses jsonObject and I am not able to parse the json array.
Not a duplicate to this :-Sending and Parsing JSON Objects or this How to parse this JSON Array in android?

Let me offer an alternate solution (of sorts). A much simpler version of your existing code would be:
Updated code:
private class DownloadJSON extends AsyncTask<Void, Void, Void> {
ProgressDialog mProgressDialog;
ArrayList<HashMap<String, String>> arraylist = new ArrayList<>();
#Override
protected void onPreExecute() {
super.onPreExecute();
mProgressDialog = new ProgressDialog(TestListActivity.this);
mProgressDialog.setTitle("Android JSON Parse Tutorial");
mProgressDialog.setMessage("Loading...");
mProgressDialog.setIndeterminate(false);
mProgressDialog.show();
}
#Override
protected Void doInBackground(Void... params) {
String url = "http://app.ireff.in:9090/IreffWeb/android?service=airtel&circle=assam";
OkHttpClient okHttpClient = new OkHttpClient();
okHttpClient.setConnectTimeout(30, TimeUnit.SECONDS);
okHttpClient.setReadTimeout(30, TimeUnit.SECONDS);
okHttpClient.setRetryOnConnectionFailure(true);
Request request = new Request.Builder()
.url(url)
.build();
Call call = okHttpClient.newCall(request);
try {
Response response = call.execute();
String strResult = response.body().string();
JSONArray JARoot = new JSONArray(strResult);
for (int i = 0; i < JARoot.length(); i++) {
JSONObject JORoot = JARoot.getJSONObject(i);
HashMap<String, String> map = new HashMap<>();
if (JORoot.has("category") && JORoot.getString("category").equals("topup")) {
if (JORoot.has("id")) {
map.put("id", JORoot.getString("id"));
}
if (JORoot.has("category")) {
map.put("category", JORoot.getString("category"));
}
if (JORoot.has("detail")) {
map.put("detail", JORoot.getString("detail"));
} else {
map.put("detail", null);
}
if (JORoot.has("price")) {
map.put("price", JORoot.getString("price"));
}
/** ADD THE COLLECTED DATA TO THE ARRAY LIST **/
arraylist.add(map); /* THE DATA WILL ONLY BE ADDED IF THE CATEGORY = "topup" */
}
}
} catch (IOException | JSONException e) {
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(Void aVoid) {
super.onPostExecute(aVoid);
ListView testList = (ListView) findViewById(R.id.testList);
TestListAdapter adapter = new TestListAdapter(TestListActivity.this, arraylist);
testList.setAdapter(adapter);
mProgressDialog.dismiss();
}
}
private class TestListAdapter extends BaseAdapter {
Activity activity;
// LAYOUTINFLATER TO USE A CUSTOM LAYOUT
LayoutInflater inflater = null;
// ARRAYLIST TO GET DATA FROM THE ACTIVITY
ArrayList<HashMap<String, String>> arrItem;
public TestListAdapter(Activity activity, ArrayList<HashMap<String, String>> arrItem) {
this.activity = activity;
// CAST THE CONTENTS OF THE ARRAYLIST IN THE METHOD TO THE LOCAL INSTANCE
this.arrItem = arrItem;
// INSTANTIATE THE LAYOUTINFLATER
inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
#Override
public int getCount() {
return arrItem.size();
}
#Override
public Object getItem(int position) {
return arrItem.get(position);
}
#Override
public long getItemId(int position) {
return position;
}
#Override
public void notifyDataSetChanged() {
super.notifyDataSetChanged();
}
#Override
public View getView(final int position, View convertView, ViewGroup parent) {
// A VIEWHOLDER INSTANCE
ViewHolder holder;
// CAST THE CONVERTVIEW IN A VIEW INSTANCE
View vi = convertView;
// CHECK CONVERTVIEW STATUS
if (convertView == null) {
// CAST THE CONVERTVIEW INTO THE VIEW INSTANCE vi
vi = inflater.inflate(R.layout.test_item, null);
// INSTANTIATE THE VIEWHOLDER INSTANCE
holder = new ViewHolder();
/***** CAST THE LAYOUT ELEMENTS *****/
/* TOP (PRIMARY) ELEMENTS */
holder.txtPrice = (TextView) vi.findViewById(R.id.txtPrice);
holder.txtDetail = (TextView) vi.findViewById(R.id.txtDetail);
// SET THE TAG TO "vi"
vi.setTag(holder);
} else {
// CAST THE VIEWHOLDER INSTANCE
holder = (ViewHolder) vi.getTag();
}
if (arrItem.get(position).get("price") != null) {
String strPrice = arrItem.get(position).get("price");
holder.txtPrice.setText("PRICE: " + strPrice);
}
if (arrItem.get(position).get("detail") != null) {
String strDetail = arrItem.get(position).get("detail");
holder.txtDetail.setText("DETAIL: " + strDetail);
} else {
holder.txtDetail.setText("DETAIL: NA");
}
return vi;
}
private class ViewHolder {
/* TOP (PRIMARY) ELEMENTS */
TextView txtPrice;
TextView txtDetail;
}
}
For the sake of completeness, I am also including the code for the adapter. It is a simple implementation. Do clean it up / optimize it / customize as per your requirement.
This piece of code has been tested prior to being posted (see screenshot of Logs at the bottom)
This uses the OkHttp library. Add this compile statement to the dependencies section of the module's gradle file: compile 'com.squareup.okhttp:okhttp:2.5.0'. Check the link for an updated version.
The example code uses if statements considering that not every record has the same set of nodes.

You BufferReader is not working as expected in your class JSONfunctions , do some changes in your class and it should looks like
JSONfunctions.java
public class JSONfunctions {
public static JSONArray getJSONfromURL(String url) {
InputStream is = null;
String result = "";
JSONArray jArray = null;
// Download JSON data from URL
try {
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(url);
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
} catch (Exception e) {
Log.e("log_tag", "Error in http connection " + e.toString());
}
StringBuffer sb = new StringBuffer("");
try {
URL urls = new URL(url);
URLConnection urlConnection;
urlConnection = urls.openConnection();
InputStream in = urlConnection.getInputStream();
BufferedReader br=new BufferedReader(new InputStreamReader(in));
String line = "";
while ((line = br.readLine()) != null) {
sb.append(line);
}
System.out.println(sb);
result=sb.toString();
} catch (IOException e) {}
catch (Exception e) {}
try {
jArray = new JSONArray(result);
} catch (JSONException e) {
Log.e("log_tag", "Error parsing data " + e.toString());
}
return jArray;
}
}
and to avoid Exception check if JSONArray is not null then only it goes to run for loop like this :
JSONArray ja2 = JSONfunctions.getJSONfromURL("http://app.ireff.in:9090/IreffWeb/android? service=airtel&circle=assam");
if(ja2!=null)
for (int i = 0; i < ja2.length(); i++) {}

jsonResponse="";
for(int i = 0; i<response.length(); i++) {
JSONObject person = (JSONObject) response.get(i);
String id = person.getString("id");
String category = person.getString("category");
}

How to Parse URL with JSON object -Android [closed]

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Improve this question
i have the URL (.com) which has the JSON object .. i created the JSON object using PHP and uploaded in a server so it will be dynamically updated (similar to RSS). I face two problems the first one shows error " and of type java.Lang.String cannot be converted to JSON object" so i used this code and the error goes:
public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser() {
}
public JSONObject getJSONFromUrl(String url) {
// Making HTTP request
try {
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 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) {
Log.e("Buffer Error", "Error converting result " + e.toString());
}
// try parse the string to a JSON object
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
// return JSON String
return jObj;
}
}
The SingleMenuItemActivity calss:
public class SingleMenuItemActivity extends Activity {
// JSON node keys
private static final String TAG_Title = "Title";
private static final String TAG_Date = "Date";
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.single_list_item);
// getting intent data
Intent in = getIntent();
// Get JSON values from previous intent
String name = in.getStringExtra(TAG_Title);
String description = in.getStringExtra(TAG_Date);
// Displaying all values on the screen
TextView lblName = (TextView) findViewById(R.id.name_label);
TextView lblCost = (TextView) findViewById(R.id.email_label);
lblName.setText(name);
lblCost.setText(description);
}
}
The AndroidJasonParsingActivity calss:
public class AndroidJSONParsingActivity extends ListActivity {
// url to make request
private static String url = "http://www.rssparser.host22.com/";
// JSON Node names
private static final String TAG_NAME = "Title";
private static final String TAG_Image = "Image";
private static final String TAG_Category = "Category";
private static final String TAG_Venue = "Venue";
private static final String TAG_Date = "Date";
// contacts JSONArray
JSONArray contacts = null;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// Hashmap for ListView
ArrayList<HashMap<String, String>> contactList = new ArrayList<HashMap<String, String>>();
// Creating JSON Parser instance
JSONParser jParser = new JSONParser();
// getting JSON string from URL
JSONObject json = jParser.getJSONFromUrl(url);
try {
// Getting Array of Contacts
//contacts = json.getJSONArray(TAG_CONTACTS);
// looping through All Contacts
for(int i = 0; i < contacts.length(); i++){
JSONObject c = contacts.getJSONObject(i);
// Storing each json item in variable
String name = c.getString(TAG_NAME);
String Image = c.getString(TAG_Image);
String Category = c.getString(TAG_Category);
String Venue = c.getString(TAG_Venue);
String Date = c.getString(TAG_Date);
// Phone number is agin JSON Object
JSONObject phone = c.getJSONObject(TAG_Date);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_NAME, name);
map.put(TAG_Image, Image);
map.put(TAG_Date , Date );
// adding HashList to ArrayList
contactList.add(map);
}
} catch (JSONException e) {
e.printStackTrace();
}
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(this, contactList,
R.layout.list_item,
new String[] { TAG_NAME, TAG_Date }, new int[] {
R.id.name, R.id.email, R.id.mobile });
setListAdapter(adapter);
// selecting single ListView item
ListView lv = getListView();
// Launching new screen on Selecting Single ListItem
lv.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String name = ((TextView) view.findViewById(R.id.name)).getText().toString();
String cost = ((TextView) view.findViewById(R.id.email)).getText().toString();
String description = ((TextView) view.findViewById(R.id.mobile)).getText().toString();
// Starting new intent
Intent in = new Intent(getApplicationContext(), SingleMenuItemActivity.class);
in.putExtra(TAG_NAME, name);
in.putExtra(TAG_Date, description);
startActivity(in);
}
});
}
}

first create JSONParser.java
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONException;
import org.json.JSONObject;
import android.util.Log;
public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// constructor
public JSONParser() {
}
public JSONObject getJSONFromUrl(String url) {
// Making HTTP request
try {
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 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) {
Log.e("Buffer Error", "Error converting result " + e.toString());
}
// try parse the string to a JSON object
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
// return JSON String
return jObj;
}
}
then create activity
public class AndroidJSONParsingActivity extends ListActivity {
// url to make request
private static String url = "http://api.androidhive.info/contacts/";
// JSON Node names
private static final String TAG_CONTACTS = "contacts";
private static final String TAG_ID = "id";
private static final String TAG_NAME = "name";
private static final String TAG_EMAIL = "email";
private static final String TAG_ADDRESS = "address";
private static final String TAG_GENDER = "gender";
private static final String TAG_PHONE = "phone";
private static final String TAG_PHONE_MOBILE = "mobile";
private static final String TAG_PHONE_HOME = "home";
private static final String TAG_PHONE_OFFICE = "office";
// contacts JSONArray
JSONArray contacts = null;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// Hashmap for ListView
ArrayList<HashMap<String, String>> contactList = new ArrayList<HashMap<String, String>>();
// Creating JSON Parser instance
JSONParser jParser = new JSONParser();
// getting JSON string from URL
JSONObject json = jParser.getJSONFromUrl(url);
try {
// Getting Array of Contacts
contacts = json.getJSONArray(TAG_CONTACTS);
// looping through All Contacts
for(int i = 0; i < contacts.length(); i++){
JSONObject c = contacts.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(TAG_ID);
String name = c.getString(TAG_NAME);
String email = c.getString(TAG_EMAIL);
String address = c.getString(TAG_ADDRESS);
String gender = c.getString(TAG_GENDER);
// Phone number is agin JSON Object
JSONObject phone = c.getJSONObject(TAG_PHONE);
String mobile = phone.getString(TAG_PHONE_MOBILE);
String home = phone.getString(TAG_PHONE_HOME);
String office = phone.getString(TAG_PHONE_OFFICE);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_ID, id);
map.put(TAG_NAME, name);
map.put(TAG_EMAIL, email);
map.put(TAG_PHONE_MOBILE, mobile);
// adding HashList to ArrayList
contactList.add(map);
}
} catch (JSONException e) {
e.printStackTrace();
}
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(this, contactList,
R.layout.list_item,
new String[] { TAG_NAME, TAG_EMAIL, TAG_PHONE_MOBILE }, new int[] {
R.id.name, R.id.email, R.id.mobile });
setListAdapter(adapter);
// selecting single ListView item
ListView lv = getListView();
// Launching new screen on Selecting Single ListItem
lv.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String name = ((TextView) view.findViewById(R.id.name)).getText().toString();
String cost = ((TextView) view.findViewById(R.id.email)).getText().toString();
String description = ((TextView) view.findViewById(R.id.mobile)).getText().toString();
// Starting new intent
Intent in = new Intent(getApplicationContext(), SingleMenuItemActivity.class);
in.putExtra(TAG_NAME, name);
in.putExtra(TAG_EMAIL, cost);
in.putExtra(TAG_PHONE_MOBILE, description);
startActivity(in);
}
});
}
}
and write Internet permission in manifest file
this is best tutorial

Where do I put the function to display the loading process?

I want to display a loading process when my application is loading data from the database.
This is my Java file.
Where do I have to put the function to display the loading process?
public class AksesServerActivity extends ListActivity {
private static String link_url = "http://plnskh.zz.mu/android/berita/cekdaftar.php";
private static final String AR_ID = "id";
private static final String AR_JUDUL = "judul";
private static final String AR_CONTENT = "content";
JSONArray artikel = null;
ArrayList<HashMap<String, String>> daftar_artikel = new ArrayList<HashMap<String, String>>();
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
JSONParser jParser = new JSONParser();
JSONObject json = jParser.AmbilJson(link_url);
try {
artikel = json.getJSONArray("artikel");
for(int i = 0; i < artikel.length(); i++){
JSONObject ar = artikel.getJSONObject(i);
String id = ar.getString(AR_ID);
String judul = ar.getString(AR_JUDUL);
String content = ar.getString(AR_CONTENT).substring(0,100)+"...(baca selengkapnya)";
HashMap<String, String> map = new HashMap<String, String>();
map.put(AR_ID, id);
map.put(AR_JUDUL, judul);
map.put(AR_CONTENT, content);
daftar_artikel.add(map);
}
} catch (JSONException e) {
e.printStackTrace();
}
this.adapter_listview();
}
public void adapter_listview() {
ListAdapter adapter = new SimpleAdapter(this, daftar_artikel,
R.layout.list_item,
new String[] { AR_JUDUL, AR_CONTENT, AR_ID}, new int[] {
R.id.judul, R.id.content, R.id.kode});
setListAdapter(adapter);
ListView lv = getListView();
lv.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,int position, long id) {
String kode = ((TextView) view.findViewById(R.id.kode)).getText().toString();
Intent in = new Intent(AksesServerActivity.this, DetailAksesServer.class);
in.putExtra(AR_ID, kode);
startActivity(in);
}
});
}
}

public class LongOperation extends AsyncTask<String, String, String>
{
ProgressDialog pdialog;
#Override
protected String doInBackground(String... params) {
JSONParser jParser = new JSONParser();
JSONObject json = jParser.AmbilJson(link_url);
try {
artikel = json.getJSONArray("artikel");
for(int i = 0; i < artikel.length(); i++){
JSONObject ar = artikel.getJSONObject(i);
String id = ar.getString(AR_ID);
String judul = ar.getString(AR_JUDUL);
String content = ar.getString(AR_CONTENT).substring(0,100)+"...(baca selengkapnya)";
HashMap<String, String> map = new HashMap<String, String>();
map.put(AR_ID, id);
map.put(AR_JUDUL, judul);
map.put(AR_CONTENT, content);
daftar_artikel.add(map);
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(String result) {
// TODO Auto-generated method stub
super.onPostExecute(result);
pdialog.dismiss();
this.adapter_listview();
}
#Override
protected void onPreExecute() {
// TODO Auto-generated method stub
super.onPreExecute();
pdialog = new ProgressDialog(NewsActivity.this);
pdialog.setMessage("Loading");
pdialog.show();
}
}
for more clarification about asynchronous task and its methods, check here

You must use AsyncTask class, override doInBackground method to perform your databse fetch, onPreExecute method to show your loading and onPostExecute to hide it. you can refer AsynTask process and AsynTask post for more information