ProgressDialog in android not shown even with Async Task

ProgressDialog in android not shown even with Async Task - android

Hello # All out there :)
I am having a little problem. I want to show a ProgressDialog when I click on Login but nothing is shown it just does the Task without the ProgressDialog. I am using a AsyncTask and opening the ProgressDialog in that thread but nothing comes up. Here is my Source Code:
It is called like this:
ProgressDialog progress = new ProgressDialog(mainActivity);
progress.setMessage("Sie werden registriert...");
jsonParser = new JSONParser(progress, url_create_user, "POST", params);
And this is the JSONParser Class:
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.List;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.params.ClientPNames;
import org.apache.http.client.params.CookiePolicy;
import org.apache.http.client.utils.URLEncodedUtils;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.ProgressDialog;
import android.content.Context;
import android.os.AsyncTask;
import android.os.Handler;
import android.os.Looper;
import android.os.Message;
import android.util.Log;
public class JSONParser extends AsyncTask<Context, Void, JSONObject>{
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
String url = "";
String method = "";
List<NameValuePair> parameters;
ProgressDialog prog;
// constructor
public JSONParser(ProgressDialog prog, String url, String method, List<NameValuePair> param) {
this.url = url;
this.method = method;
this.parameters = param;
this.prog = prog;
}
private Handler handler = new Handler() {
#Override
public void handleMessage(Message msg) {
if (msg.what == 0)
{
prog.show();
}
else
{
prog.dismiss();
}
}
};
#Override
protected JSONObject doInBackground(Context... params) {
try {
handler.sendEmptyMessage(0);
// Überprüfen welche Request Methode benutzt werden soll
if(method == "POST"){
DefaultHttpClient httpClient = new DefaultHttpClient();
httpClient.getParams().setParameter(ClientPNames.COOKIE_POLICY,
CookiePolicy.BROWSER_COMPATIBILITY);
HttpPost httpPost = new HttpPost(url);
httpPost.setEntity(new UrlEncodedFormEntity(this.parameters));
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
}else if(method == "GET"){
DefaultHttpClient httpClient = new DefaultHttpClient();
String paramString = URLEncodedUtils.format(this.parameters, "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();
}
//Stream in ein String umwandeln
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("Fehler!", "Fehler mein umwandeln von Stream in String: " + e.toString());
}
// JSON Object parsen
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error beim parsen " + e.toString());
}
handler.sendEmptyMessage(1);
// Das JSONObject zurückgeben
return jObj;
}
}

see the following example code of JSON parser with async task
package com.androidhive.jsonparsing;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.HashMap;
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.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 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";
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
// contacts JSONArray
JSONArray contacts = null;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
new GetEventsTask().execute("");
}
protected class GetEventsTask extends
AsyncTask<String, Integer, ArrayList<HashMap<String, String>>> {
protected ArrayList<HashMap<String, String>> contactList;
private final ProgressDialog dialog = new ProgressDialog(
AndroidJSONParsingActivity.this);
//PreExecute Method
protected void onPreExecute() {
this.dialog.setMessage("Loading, Please Wait..");
this.dialog.setCancelable(false);
this.dialog.show();
}
//doInBackground Method
#Override
protected ArrayList<HashMap<String, String>> doInBackground(
String... params) {
contactList = new ArrayList<HashMap<String, String>>();
// 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();
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 (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
// try parse the string to a JSON object
try {
jObj = new JSONObject(json);
Log.i("json objects",""+json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
try {
// Getting Array of Contacts
contacts = jObj.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();
}
return contactList;
}
//onPostExecute Method
protected void onPostExecute(ArrayList<HashMap<String, String>> result) {
ListAdapter adapter = new SimpleAdapter(getApplicationContext(),
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 });
// selecting single ListView item
ListView lv = getListView();
lv.setAdapter(adapter);
// 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);
}
});
if (this.dialog.isShowing()) {
this.dialog.dismiss();
}
}
}
}
Let me know your problem is resolved or not?

you can't compare == between 2 string
Use:
method.equals("POST");

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// Depends on your web service
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String result = null;
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inputStream = entity.getContent();
// json is UTF-8 by default
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream, "UTF-8"), 8);
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} catch (JSONException e) {
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to set the height of the ImageView:
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how is it possible to parse some Json Data from web and put them in a listview.
Inside of them i would like to search something, I'm searching now for a while in the internet but I wasn't successfull.
I still can Parse JSON and pu them in a listview but how can I search?
Here my Code
MainAct.:
import java.util.ArrayList;
import java.util.HashMap;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.app.ProgressDialog;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity {
ListView list;
TextView ver;
TextView name;
TextView api;
Button Btngetdata;
ArrayList<HashMap<String, String>> oslist = new ArrayList<HashMap<String, String>>();
//URL to get JSON Array
private static String url = "*****";
//JSON Node Names
private static final String TAG_OS = "android";
private static final String TAG_VER = "ver";
private static final String TAG_NAME = "name";
private static final String TAG_API = "api";
JSONArray android = null;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
oslist = new ArrayList<HashMap<String, String>>();
Btngetdata = (Button)findViewById(R.id.getdata);
Btngetdata.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
new JSONParse().execute();
}
});
}
private class JSONParse extends AsyncTask<String, String, JSONObject> {
private ProgressDialog pDialog;
#Override
protected void onPreExecute() {
super.onPreExecute();
ver = (TextView)findViewById(R.id.vers);
name = (TextView)findViewById(R.id.name);
api = (TextView)findViewById(R.id.api);
pDialog = new ProgressDialog(MainActivity.this);
pDialog.setMessage("Getting Data ...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
}
#Override
protected JSONObject doInBackground(String... args) {
JSONParser jParser = new JSONParser();
// Getting JSON from URL
JSONObject json = jParser.getJSONFromUrl(url);
return json;
}
#Override
protected void onPostExecute(JSONObject json) {
pDialog.dismiss();
try {
// Getting JSON Array from URL
android = json.getJSONArray(TAG_OS);
for(int i = 0; i < android.length(); i++){
JSONObject c = android.getJSONObject(i);
// Storing JSON item in a Variable
String ver = c.getString(TAG_VER);
String name = c.getString(TAG_NAME);
String api = c.getString(TAG_API);
// Adding value HashMap key => value
HashMap<String, String> map = new HashMap<String, String>();
map.put(TAG_VER, ver);
map.put(TAG_NAME, name);
map.put(TAG_API, api);
oslist.add(map);
list=(ListView)findViewById(R.id.list);
ListAdapter adapter = new SimpleAdapter(MainActivity.this, oslist,
R.layout.list_v,
new String[] { TAG_VER,TAG_NAME, TAG_API }, new int[] {
R.id.vers,R.id.name, R.id.api});
list.setAdapter(adapter);
list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
Toast.makeText(MainActivity.this, "You Clicked at "+oslist.get(+position).get("name"), Toast.LENGTH_SHORT).show();
}
});
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}
}
JSONParser:
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;
}
}

List<list> varr = yourlist;
for (list result : varr) {
// action such as.. if result
}
hope this help

Trouble in getting data from webserver

I wrote this code to read and write data from webserver (mysql databse) and then all the data will be show on my andriod application.
In this regard I used PHP services for reading and writing the data from web server. Everything is working fine it gets data from web server correctly but when it reaches at this line:
int success = jsonObject.getInt(TAG_SUCCESS);
It shows a null pointer exception I don't know why but it actually made me insane.
Code:
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import org.apache.http.NameValuePair;
import org.apache.commons.collections.*;
//import org.json.JSONObject;
import android.os.AsyncTask;
import android.os.Bundle;
import android.app.Activity;
import android.app.ProgressDialog;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import org.json.*;
public class MiddleActivity extends Activity {
Button btnMiddleDB;
ProgressDialog pDialog ;
JSONParser jsonParser = new JSONParser();
JSONArray places = null;
private static final String URL = "http://192.168.1.2/android_connect/get_all_products.php";
// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_PRODUCTS = "products";
private static final String TAG_PID = "pid";
private static final String TAG_NAME = "name";
ArrayList<HashMap<String, String>> placesList;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_middle);
new LoadGettingFromDatabase().execute();
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#Override
public void onClick(View arg0) {
}
});
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running background thread for getting data from webserver
class LoadGettingFromDatabase extends AsyncTask<String, String, String>{
#Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(MiddleActivity.this);
pDialog.setMessage("Getting from database...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
}
**after getting data from webserver parse it to json and store it into string**
#Override
protected String doInBackground(String... args) {
List<NameValuePair> params = new ArrayList<NameValuePair>();
Log.d("Seen","seen1");
JSONObject jsonObject = jsonParser.makeHttpRequest(URL, "GET" ,params);
Log.d("String","JSON 2");
//Log.d("All entries","Entries" + jsonObject.toString());
try{
Log.d("Seen","seen2");
ACTUALLY THE PROBLEM IS HERE
int success = jsonObject.getInt(TAG_SUCCESS);
Log.d("Seen","seen5");
if(success == 1){
//Entries found
Log.d("Seen","seen6");
places = jsonObject.getJSONArray(TAG_PRODUCTS);
for(int i=0;i<places.length();i++){
JSONObject temp = places.getJSONObject(i);
String id = temp.getString(TAG_PID);
String name = temp.getString(TAG_NAME);
HashMap<String, String> hashMap = new HashMap<String, String>();
hashMap.put(TAG_PID, id);
hashMap.put(TAG_NAME, name);
placesList.add(hashMap);
}
}
} catch (Exception e) {
Log.e("success","success status " + e);
}
return null;
}
public void onProExecute(String file_url){
pDialog.dismiss();
runOnUiThread(new Runnable(){
public void run(){
ListAdapter listAdapter = new SimpleAdapter(MiddleActivity.this, placesList, R.layout.list_item, new String[]{
TAG_PID, TAG_NAME},new int[]{R.id.ID, R.id.Name});
ListView listView = (ListView) findViewById(R.layout.list_item);
listView.setAdapter(listAdapter);
};
});
};
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_middle, menu);
return true;
}
}
**and log cat is**
05-07 00:29:54.419: D/Seen(30282): seen1
05-07 00:29:54.569: D/Seen(30282): seen3
05-07 00:29:54.909: D/Seen(30282): seen4
05-07 00:29:54.979: D/String(30282): JSON get_all_products.php
05-07 00:29:54.979: D/String(30282): db_connect.php
05-07 00:29:54.979: D/String(30282): db_config.php
05-07 00:29:54.979: D/String(30282): {"success":0,"message":"No products found
05-07 00:29:55.300: D/String(30282): JSON 1
05-07 00:29:55.300: D/String(30282): JSON 2
05-07 00:29:55.310: D/Seen(30282): seen2
**05-07 00:29:55.310: E/success(30282): success status
java.lang.NullPointerException**
and here is my jsonparser class
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.List;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.utils.URLEncodedUtils;
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() {
}
// function get json from url
// by making HTTP POST or GET method
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 {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
// return JSON String
return jObj;
}
}

Your jsonObject is null, debug the app by setting breakpoint at line->
JSONObject jsonObject = jsonParser.makeHttpRequest(URL, "GET" ,params);
And check value of jsonObject.

Android-Json parser not able to display data retrieved from back end

I am new to android. I am implementing a project in which I want to get the data from the back end and display on my android screen.
The Json I am trying to call is:-
[{"admin":null,"card_no":"8789","created_at":"2013-04-09T12:55:54Z","deleted":0,"email":"dfds#fgfd.com","entered_by":null,"first_name":"Gajanan","id":8,"last_name":"Bhat","last_updated_by":null,"middle_name":"","mobile":87981,"updated_at":"2013-04-13T05:26:25Z","user_type_id":null},{"admin":{"created_at":"2013-04-10T09:02:00Z","deleted":0,"designation":"Sr software Engineer","email":"admin#qwe.com","first_name":"Chiron","id":1,"last_name":"Synergies","middle_name":"Sr software Engineer","office_phone":"98789765","super_admin":false,"updated_at":"2013-04-10T12:03:04Z","username":"Admin"},"card_no":"66","created_at":"2013-04-08T09:47:15Z","deleted":0,"email":"rajaarun1991","entered_by":1,"first_name":"Arun","id":1,"last_name":"Raja\n","last_updated_by":1,"middle_name":"Nagaraj","mobile":941,"updated_at":"2013-04-08T09:47:15Z","user_type_id":1}]
My JsonParser.java is as follows:-
package com.example.library;
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.StatusLine;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.util.Log;
import android.util.Log;
public class JSONParser {
static InputStream is = null;
static JSONArray jarray = null;
static String json = "";
// constructor
public JSONParser() {
}
public JSONArray getJSONFromUrl(String url) {
StringBuilder builder = new StringBuilder();
HttpClient client = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(url);
try {
HttpResponse response = client.execute(httpGet);
StatusLine statusLine = response.getStatusLine();
int statusCode = statusLine.getStatusCode();
if (statusCode == 200) {
HttpEntity entity = response.getEntity();
InputStream content = entity.getContent();
BufferedReader reader = new BufferedReader(new InputStreamReader(content));
String line;
while ((line = reader.readLine()) != null) {
builder.append(line);
}
} else {
Log.e("==>", "Failed to download file");
}
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
// try parse the string to a JSON object
try {
jarray = new JSONArray( builder.toString());
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
// return JSON String
return jarray;
}
}
/* public void writeJSON() {
JSONObject object = new JSONObject();
try {
object.put("name", "");
object.put("score", new Integer(200));
object.put("current", new Double(152.32));
object.put("nickname", "Programmer");
} catch (JSONException e) {
e.printStackTrace();
}
System.out.println(object);
}
*/
And my activity.java is as follows:-
package com.example.library;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.app.ListActivity;
import android.app.ProgressDialog;
import android.content.Context;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
public class SecondActivity extends Activity
{
private Context context;
private static String url = "http://192.168.0.100:3000/users.json";
private static final String TAG_ID = "id";
private static final String TAG_FIRST_NAME = "first_name";
private static final String TAG_MIDDLE_NAME = "middle_name";
private static final String TAG_LAST_NAME = "last_name";
// private static final String TAG_POINTS = "experiencePoints";
ArrayList<HashMap<String, String>> jsonlist = new ArrayList<HashMap<String, String>>();
ListView lv ;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
new ProgressTask(SecondActivity.this).execute();
}
private class ProgressTask extends AsyncTask<String, Void, Boolean> {
private ProgressDialog dialog;
public ProgressTask(SecondActivity secondActivity) {
Log.i("1", "Called");
context = secondActivity;
dialog = new ProgressDialog(context);
}
/** progress dialog to show user that the backup is processing. */
/** application context. */
private Context context;
protected void onPreExecute() {
this.dialog.setMessage("Progress start");
this.dialog.show();
}
#Override
protected void onPostExecute(final Boolean success) {
if (dialog.isShowing()) {
dialog.dismiss();
}
ListAdapter adapter = new SimpleAdapter(context, jsonlist,
R.layout.list_item, new String[] { TAG_ID, TAG_FIRST_NAME,
TAG_MIDDLE_NAME, TAG_LAST_NAME }, new int[] {
R.id.id, R.id.first_name, R.id.middle_name,
R.id.last_name });
setListAdapter(adapter);
// selecting single ListView item
lv = getListView();
}
private void setListAdapter(ListAdapter adapter) {
// TODO Auto-generated method stub
}
protected Boolean doInBackground(final String... args) {
JSONParser jParser = new JSONParser();
// getting JSON string from URL
JSONArray json = jParser.getJSONFromUrl(url);
for (int i = 0; i < json.length(); i++) {
try {
JSONObject c = json.getJSONObject(i);
String id = c.getString(TAG_ID);
String first_name = c.getString(TAG_FIRST_NAME);
String middle_name = c.getString(TAG_MIDDLE_NAME);
String last_name = c.getString(TAG_LAST_NAME);
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_ID, id);
map.put(TAG_FIRST_NAME, first_name);
map.put(TAG_MIDDLE_NAME, middle_name);
map.put(TAG_LAST_NAME, last_name);
jsonlist.add(map);
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return null;
}
}
public ListView getListView() {
// TODO Auto-generated method stub
return null;
}
}
I am not able to show anything on the emulators for users,whereas I am able to fetch the data from the server
Actually in the project I want to display all the users present in the library.I am accessing the server which is on Ubuntu.
The following message is displayed on the console(Terminal):-
Started GET "/users.json" for 192.168.0.104 at 2013-05-05 22:05:01 -0700
Processing by UsersController#index as JSON
User Load (0.4ms) SELECT "users".* FROM "users" WHERE (users.deleted = 0) ORDER BY users.id DESC
Admin Load (0.3ms) SELECT "admins".* FROM "admins" WHERE "admins"."id" = 1 AND (admins.deleted = 0) ORDER BY admins.id DESC LIMIT 1
Completed 200 OK in 4ms (Views: 2.1ms | ActiveRecord: 0.6ms)
[2013-05-05 22:05:01] WARN Could not determine content-length of response body. Set content-length of the response or set Response#chunked = true
However i am not able to display the data on the android screen/emulator.
Please help me with this.

I missed your setAdapterList()method.
Any error for your json pasers? and can you put your activity which is inherited from SecondActivity?
//modify getListView
public ListView getListView() {
// TODO Auto-generated method stub
listView = (ListView)findViewById(r.your.listview);
return listView;
}
//modify setListAdapter
private void setListAdapter(ListAdapter adapter) {
// TODO Auto-generated method stub
lv.setAdapter(adapter);
}

Parsing JSON in Android

I am about to work with JSON for the first time. Previously I worked on parsing XML in Android. How is it different with JSON? Suggest me some good tutorials for the same.
Stone

Do you mean JSON? You can parse JSON very easily on Android. You can either use the built-in org.json parser or use a third-party library, such as google-gson, or any other Java JSON library.

You actually mean JSON right? If you're wondering about the JSON structure http://www.json.org/ is a great place to start.
I have never used JSON with android, but Googling give me this looks-promising tutorial http://www.javacodegeeks.com/2011/01/android-json-parsing-gson-tutorial.html

full code which run succesfully..........
package com.example.jsonparsingapp;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.HashMap;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.StatusLine;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.ListActivity;
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 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";
JSONObject json;
// contacts JSONArray
JSONArray contacts = null;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
new RetreiveFeedTask().execute("hbhbh");
}
class RetreiveFeedTask extends AsyncTask<String,String,String> {
private Exception exception;
RetreiveFeedTask()
{
}
#Override
protected void onPreExecute( ) {
// TODO Auto-generated method stub
super.onPreExecute();
}
protected String doInBackground(String... urls)
{
try{
System.out.println("in doinbackground");
StringBuilder builder = new StringBuilder();
HttpClient client = new DefaultHttpClient();
HttpGet httpGet = new HttpGet("http://api.androidhive.info/contacts/");
try {
HttpResponse response = client.execute(httpGet);
StatusLine statusLine = response.getStatusLine();
int statusCode = statusLine.getStatusCode();
if (statusCode == 200) {
HttpEntity entity = response.getEntity();
InputStream content = entity.getContent();
BufferedReader reader = new BufferedReader(new InputStreamReader(content));
String line;
while ((line = reader.readLine()) != null) {
builder.append(line);
}
}
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
json=new JSONObject(builder.toString());
System.out.println("string issssss"+builder.toString());
System.out.println("in doinbackground end");
}catch(Exception e)
{
e.printStackTrace();
}
return "hi";
}
protected void onPostExecute(String s) {
// TODO: check this.exception
// TODO: do something with the feed
System.out.println("postexecute");
doWork();
}
}
public void doWork()
{
// 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);
//System.out.println("json is"+json);
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
}
}

Develop Reference

The Android operating system is a mobile operating system that was developed by Google (GOOGL?) to be primarily used for touchscreen devices, cell phones, and tablets.

ProgressDialog in android not shown even with Async Task - android

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