Bringing back the app to front from a service

Bringing back the app to front from a service - java

Pretty new in Android.
The problem here is simple.
My app needs to be waken up in some interval of time.
The problem is that I can`t call it properly.
There in the comment // HERE IS THE PROBLEM the code is breaking giving me error that cant find context and to declare it.
public class BackgroundService extends Service {
Integer background_connect = null;
String SERVER_IP;
String APP_ID;
private Context context;
#Override
public IBinder onBind(Intent arg0) {
return null;
}
#Override
public void onCreate() {
super.onCreate();
DB_Queries db = new DB_Queries(getApplicationContext());
Cursor c = db.getSettings();
StringBuilder app_id = new StringBuilder();
StringBuilder server_ip = new StringBuilder();
if (c.moveToFirst()) {
do {
server_ip.append(c.getString(c.getColumnIndex("server_ip")));
app_id.append(c.getString(c.getColumnIndex("app_id")));
} while (c.moveToNext());
}
db.close();
SERVER_IP = server_ip.toString();
APP_ID = app_id.toString();
}
#Override
public void onDestroy() {
super.onDestroy();
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
requestServerDelay delay = new requestServerDelay();
delay.execute("http://" + SERVER_IP + "/index.php/app/requestAppRecall");
return super.onStartCommand(intent, flags, startId);
}
private class requestServerDelay extends AsyncTask<String, Void, Void> {
#Override
protected Void doInBackground(String... params) {
HttpClient client = new DefaultHttpClient();
HttpPost post = new HttpPost(params[0]);
post.addHeader("Content-type", "application/x-www-form-urlencoded");
List<NameValuePair> pair = new ArrayList<NameValuePair>();
pair.add(new BasicNameValuePair("app_id", APP_ID));
try {
post.setEntity(new UrlEncodedFormEntity(pair));
HttpResponse response = client.execute(post);
InputStream is = response.getEntity().getContent();
InputStreamReader isr = new InputStreamReader(is);
BufferedReader br = new BufferedReader(isr);
StringBuilder str = new StringBuilder();
String chunk = null;
while ((chunk = br.readLine()) != null) {
str.append(chunk);
}
background_connect = Integer.parseInt(str.toString());
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(Void result) {
Handler handler = new Handler();
handler.postDelayed(new Runnable() {
public void run() {
//HERE IS THE PROBLEM
Intent intent = new Intent(getApplication().getApplicationContext(), getApplication().getApplicationContext().getClass());
intent.addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
intent.addFlags(Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED);
intent.addFlags(Intent.FLAG_ACTIVITY_PREVIOUS_IS_TOP);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
getApplication().getApplicationContext().startActivity(intent);
}
}, background_connect * 60 * 1000);
}
}
}

If the requestServerDelay task is in the service, you can use getApplicationContext().startActivity(...) to start an activity.
No need for getApplication() before.
Alternatively You can keep a Context member in the Service class (mContext) and use it.

Related

Call ASyncTask for notification

I want use AsyncTask on my app for sending notification to my user when on a website, the JSON Value =\= false.
The AsyncTask is as:
public class ASyncTask extends AsyncTask<String, Void, String> {
private static boolean onair;
public static final String TAG = "[NOTIF]";
private final static int INTERVAL = 1000; //2 minutes
Handler mHandler = new Handler();
private final HttpClient httpclient = new DefaultHttpClient();
final HttpParams params = httpclient.getParams();
HttpResponse response;
private String content = null;
private boolean error = false;
private Context mContext;
private int NOTIFICATION_ID = 1;
private Notification mNotification;
private NotificationManager mNotificationManager;
Runnable mHandlerTask = new Runnable() {
#Override
public void run() {
detectonline_prepare();
mHandler.postDelayed(mHandlerTask, INTERVAL);
}
};
public ASyncTask(Context context){
this.mContext = context;
//Get the notification manager
mNotificationManager = (NotificationManager) mContext.getSystemService(Context.NOTIFICATION_SERVICE);
}
protected void onPreExecute() {
Log.i(TAG, "Erreur onPretExecute");
}
protected String doInBackground(String... urls) {
detectonline_prepare();
return content;
}
protected void onCancelled() {
createNotification("Une erreur s'est produite",content);
}
protected void onPostExecute(String content) {
detectonline_prepare();
if (error) {
Log.i(TAG, "Erreur onPostExecute");
} else {
Log.i(TAG, "[NOTIF] OK");
createNotification("ok","ok");
}
}
private void createNotification(String contentTitle, String contentText) {
//Build the notification using Notification.Builder
Notification.Builder builder = new Notification.Builder(mContext)
.setSmallIcon(android.R.drawable.stat_sys_download)
.setAutoCancel(true)
.setContentTitle(contentTitle)
.setContentText(contentText);
//Get current notification
mNotification = builder.getNotification();
//Show the notification
mNotificationManager.notify(NOTIFICATION_ID, mNotification);
}
public void detectonline_prepare(){
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
try {
detectonline();
} catch (JSONException | IOException e) {
e.printStackTrace(System.out);
}
}
public void detectonline() throws JSONException, IOException {
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
checkIfOnline();
if (onair == false) {
Log.i(TAG, "Variable OFF");
} else {
//createNotification();
Log.i(TAG, "Variable ON");
}
}
public static void checkIfOnline() throws JSONException, IOException {
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
String channerUrl = "https://api.dailymotion.com/video/x3p6d9r?fields=onair";
String jsonText = readFromUrl(channerUrl);// reads text from URL
JSONObject json = new JSONObject(jsonText); // You create a json object from your string jsonText
if (json.has("onair")) { // just a simple test to check the node that you need existe
//boolean onair = json.getBoolean("onair"); // In the url that you gave onair value is boolean type
onair = json.getBoolean("onair");
return;
}
}
private static String readFromUrl(String url) throws IOException {
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
URL page = new URL(url);
StringBuilder sb = new StringBuilder();
Scanner scanner = null;
try {
scanner = new Scanner(page.openStream());
while (scanner.hasNextLine()) {
sb.append(scanner.nextLine());
}
} finally {
if (scanner != null)
scanner.close();
}
return sb.toString();
}
But I want to know how this work. How I can call from my MainActivity this AsyncTask (for this to work in the background).
Thank you

AsynTask are basically threads that let you do operations in separate thread (non-UI that is the main thread).
You don't need AsynTask for notifications, it can be achieved using PendingIntent and Listeners like a phone call, touch listener, etc.
Now coming to your question try this:
In your main thread do the following:
ASynsTask myAsyncTask = new ASyncTask(getApplicationContext());
myAsyncTask.execute();
Tutorial: Good read

Java Interface Callback on Android

I am currently trying to make an android app that basically downloads strings from a url. But I want to make it object oriented. My mainActivity gets string from webService which downloads string when button is clicked. But I am not good at interfaces and callbacks. What should I do to make this code run?
public class MainActivity extends Activity implements WebServiceInterface{
private TextView textView;
private Button readWebPage;
private WebService service;
private WebServiceInterface webServiceInterface;
private String response;
/**
* Called when the activity is first created.
*/
#Override
public void onCreate(final Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textView = (TextView) findViewById(R.id.TextView01);
readWebPage = (Button) findViewById(R.id.readWebpage);
service = new WebService();
readWebPage.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
service.execute(new String[]{"http://google.com/"});
onSuccess(response);
}
});
}
#Override
public void onSuccess(String response) {
textView.setText(Html.fromHtml(response));
}
#Override
public void onFail(Exception ex) {
textView.setText(ex.getLocalizedMessage());
}
}
public class WebService extends AsyncTask<String, Void, String> {
private WebServiceInterface webServiceInterface;
#Override
protected String doInBackground(String... urls) {
String response = "";
for (String url : urls) {
DefaultHttpClient client = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(url);
try {
HttpResponse execute = client.execute(httpGet);
InputStream content = execute.getEntity().getContent();
BufferedReader buffer = new BufferedReader(
new InputStreamReader(content));
String s = "";
while ((s = buffer.readLine()) != null) {
response += s;
}
webServiceInterface.onSuccess(response);
} catch (Exception e) {
e.printStackTrace();
webServiceInterface.onFail(e);
}
}
return response;
}
#Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
}
}
public interface WebServiceInterface {
void onSuccess(String response);
void onFail(Exception ex);
}

you need to create one public method for set webServiceInterface in WebService class like
public setWebServiceInterface (WebServiceInterface listener)
{
this.webServiceInterface =listener;
}
in MainActivity activity call this method and pass argument this
service.setWebServiceInterface (this);
in WebService class in onPostExecute Method call
webServiceInterface.onSuccess(s);

Add WebService (WebServiceInterface webServiceInterface) in your AsyncTask as a constructor.
service = new WebService(new WebServiceInterface (){
void onSuccess(String response){
//do your stuff
}
void onFail(Exception ex){
//do your stuff
}
});
and in your asynctask
public class WebService extends AsyncTask<String, Void, String> {
public WebService (WebServiceInterface webServiceInterface){
this.webinterface= webServiceInterface;
}
private WebServiceInterface webinterface;
#Override
protected String doInBackground(String... urls) {
String response = "";
for (String url : urls) {
DefaultHttpClient client = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(url);
try {
HttpResponse execute = client.execute(httpGet);
InputStream content = execute.getEntity().getContent();
BufferedReader buffer = new BufferedReader(
new InputStreamReader(content));
String s = "";
while ((s = buffer.readLine()) != null) {
response += s;
}
webinterface.onSuccess(response);
} catch (Exception e) {
e.printStackTrace();
webinterface.onFail(e);
}
}
return response;
}
#Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
}
}

I have found the problem, it is because of runOnUiThread is missing.

Get variable value OnpostExecute (Async)

I need to get the value of an id that is within my OnpostExecute.
Look into my class that contains OnPostExecute:
listaPedido.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> lista, View item, int posicao, long id) {
listaPedido.getItemAtPosition(posicao);
if (posicao == 0) {
AlertDialog.Builder builder = new AlertDialog.Builder(FinalizarPedido.this);//Cria o gerador do AlertDialog
builder.setTitle("Item: " + posicao);
builder.setMessage("Categoria: " + pedidos_categoria.get(0) + "\nDescrição: " + pedidos_descricao.get(0) + "\nQtd: " + pedidos_qtd.get(0) + "\nUnidade: " + pedidos_unidade.get(0));
builder.setNegativeButton("Fechar", null);
builder.setPositiveButton("Excluir", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialogInterface, int i) {
String id = pedidos_id.get(0);
new delete().execute();
}
});
alerta = builder.create();
alerta.show();
So I try to change my class to delete calling the String value "id", but I can not in any way take this value OnPostExecute.
class delete extends android.os.AsyncTask<String, Integer, String> {
private StringBuilder sb;
private ProgressDialog pr;
private HttpResponse req;
private InputStream is;
#Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(FinalizarPedido.this);
pDialog.setMessage("Excluindo pedido ...");
pDialog.setIndeterminate(false); pDialog.setCancelable(true);
pDialog.show();
}
#Override
protected String doInBackground(String... arg0) {
UserAccessSession userAccess = UserAccessSession.getInstance(FinalizarPedido.this);
UserSession userSession = userAccess.getUserSession();
ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
select objetoselect = new select();
nameValuePairs.add(new BasicNameValuePair("pedidos_id", objetoselect.id));
try
{
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://guiaserudgeramos.com.br/buysell/pedidos_del.php");
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
InputStreamReader ireader = new InputStreamReader(is);
BufferedReader bf = new BufferedReader(ireader);
sb = new StringBuilder();
String line = null;
while ((line = bf.readLine()) != null) {
sb.append(line);
}
Log.e("pass 1", "connection success ");
}
catch(Exception e)
{
Log.e("Fail 1", e.toString());
Toast.makeText(getApplicationContext(), "Invalid IP Address",
Toast.LENGTH_LONG).show();
}
return id;
}
#Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
pDialog.dismiss();
Toast.makeText(getApplicationContext(), "Pedido deletado com sucesso", Toast.LENGTH_LONG).show();
}
}
}

I didn't understand what you was doing but you can do it with using this way. You have to get some variables and classes from another Activity by delete class Constructor.
class delete extends android.os.AsyncTask<String, Integer, String> {
private StringBuilder sb;
private ProgressDialog pr;
private HttpResponse req;
private InputStream is;
private Context context;
public delete(Context _context, ProgressDialog dialog, InputStream input )
{
context = _context;
pr = dialog;
is = input;
}
#Override
protected void onPreExecute() {
super.onPreExecute();
/*
Your operations
*/
}
#Override
protected String doInBackground(String... arg0) {
/*
Your operations
*/
}
#Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
/*
Your operations
*/
}
}
}

Json response is very slow android

I'm writing an Android application which will occasionally need to download a json string of around 1MB and containing around 1000 elements, and parse each of these into an SQLite database, which I use to populate a ListActivity.
Even though the downloading and parsing isn't something that needs to be done on every interaction with the app (only on first run or when the user chooses to refresh the data), I'm still concerned that the parsing part is taking too long, at around two to three minutes - it seems like an eternity in phone app terms!
I am using this code... :-
public class CustomerAsyncTask extends AsyncTask<String, Integer, String> {
private Context context;
private String url_string;
private String usedMethod;
private String identifier;
List<NameValuePair> parameter;
private boolean runInBackground;
AsynTaskListener listener;
private Bitmap bm = null;
public ProgressDialog pDialog;
public String entityUtil;
int index = 0;
public static int retry = 0;
private String jsonString = "";
private String DialogString = "";
// use for AsyncTask web services-----------------
public CustomerAsyncTask(Context ctx, String url, String usedMethod,
String identifier, boolean runInBackground, String DialogString,
List<NameValuePair> parameter, AsynTaskListener callack) {
this.context = ctx;
this.url_string = url;
this.usedMethod = usedMethod;
this.identifier = identifier;
this.parameter = parameter;
this.runInBackground = runInBackground;
this.listener = callack;
this.DialogString = DialogString;
}
public CustomerAsyncTask(Context ctx, String url, String usedMethod,
String identifier, boolean runInBackground,
List<NameValuePair> parameter, AsynTaskListener callack, Bitmap bm) {
this.context = ctx;
this.url_string = url;
this.usedMethod = usedMethod;
this.identifier = identifier;
this.parameter = parameter;
this.runInBackground = runInBackground;
this.listener = callack;
this.bm = bm;
}
#Override
protected void onPreExecute() {
// TODO Auto-generated method stub
super.onPreExecute();
if (runInBackground)
initProgressDialog(DialogString);
}
#Override
protected void onProgressUpdate(Integer... values) {
// TODO Auto-generated method stub
super.onProgressUpdate(values);
}
#SuppressWarnings("deprecation")
#Override
protected String doInBackground(String... params) {
HttpParams httpParameters = new BasicHttpParams();
int timeoutConnection = 10000; // mili second
HttpConnectionParams.setConnectionTimeout(httpParameters,
timeoutConnection);
int timeoutSocket = 10000;
HttpConnectionParams.setSoTimeout(httpParameters, timeoutSocket);
DefaultHttpClient httpClient = new DefaultHttpClient(httpParameters);
try {
HttpResponse response = null;
if (usedMethod.equals(GlobalConst.POST)) {
HttpPost httppost = new HttpPost(this.url_string);
httppost.setHeader("Content-Type",
"application/x-www-form-urlencoded");
// Customer Login MObile
if (identifier.equals("Customer_Login")) {
if (params.length > 0) {
parameter = new ArrayList<NameValuePair>();
parameter.add(new BasicNameValuePair("cus_mob",
params[0]));
}
httppost.setEntity(new UrlEncodedFormEntity(parameter));
// Customer Verify Code
} else if (identifier.equals("Customer_mob_verify")) {
if (params.length > 0) {
parameter = new ArrayList<NameValuePair>();
parameter.add(new BasicNameValuePair("cus_verify",
params[0]));
parameter.add(new BasicNameValuePair("cus_mobile",
params[1]));
}
httppost.setEntity(new UrlEncodedFormEntity(parameter));
} else if (identifier.equals("Dashboard")) {
if (params.length > 0) {
parameter = new ArrayList<NameValuePair>();
parameter.add(new BasicNameValuePair("cus_id",
params[0]));
}
httppost.setEntity(new UrlEncodedFormEntity(parameter));
}
response = (HttpResponse) httpClient.execute(httppost);
} else if (usedMethod.equals(GlobalConst.GET)) {
HttpGet httpput = new HttpGet(this.url_string);
httpput.setHeader("Content-Type",
"application/x-www-form-urlencoded");
response = (HttpResponse) httpClient.execute(httpput);
}
// Buffer Reader------------------------
InputStream inputStream = null;
String result = null;
try {
HttpEntity entity1 = response.getEntity();
inputStream = entity1.getContent();
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) {
} finally {
try {
if (inputStream != null)
inputStream.close();
} catch (Exception squish) {
}
}
jsonString = result;
} catch (ClientProtocolException e) {
e.printStackTrace();
return AsyncResultConst.CONNEERROR;
} catch (IOException e) {
e.printStackTrace();
return AsyncResultConst.CONNEERROR;
} catch (Exception e1) {
e1.printStackTrace();
return AsyncResultConst.EXCEPTION;
} finally {
httpClient.getConnectionManager().shutdown();
}
return AsyncResultConst.SUCCESS;
}
#Override
protected void onPostExecute(String result) {
// TODO Auto-generated method stub
if (runInBackground)
pDialog.dismiss();
if (result.equals(AsyncResultConst.SUCCESS)) {
listener.onRecieveResult(identifier, jsonString);
} else if (result.equals(AsyncResultConst.PARSINGERROR)) {
// showAlertMessage(context, "Error", "Parsing Error", null);
listener.onRecieveException(identifier, result);
} else {
if (retry < 0) {
retry++;
new CustomerAsyncTask(context, url_string, usedMethod,
identifier, runInBackground, DialogString, parameter,
listener).execute("");
} else {
// showAlertMessage(context, "Error", "Connection Error", null);
listener.onRecieveException(identifier, result);
}
}
super.onPostExecute(result);
}
private void initProgressDialog(String loadingText) {
pDialog = new ProgressDialog(this.context);
pDialog.setMessage(loadingText);
pDialog.setCancelable(false);
pDialog.show();
}
}

Don't use Async-task in such case, use native java thread here.
new Thread(new Runnable() {
public void run() {
// Do your work .....
}
}).start();
When need to update UI. Yes! Android won't allow you to do that. so... solution is: USE Handler for that :)
Handler handler = new Handler();
handler.post(new Runnable() {
#Override
public void run() {
// Do Update your UI
}
});
Use AsyncTask for:
Simple network operations which do not require downloading a lot of
data Disk-bound tasks that might take more than a few milliseconds
Use Java threads for:
Network operations which involve moderate to large amounts of data (either uploading or downloading)
High-CPU tasks which need to be run in the background
Any task where you want to control the CPU usage relative to the GUI thread

You could use Google's GSON as well.

Try to use Jackson Library to manage your JSON. It is really efficient. You can find it here : http://mvnrepository.com/artifact/org.codehaus.jackson/jackson-jaxrs
I am using it for a 400KB file is less than 1 second.
If you want a tuto this one looks good http://www.mkyong.com/java/how-to-convert-java-object-to-from-json-jackson/

This is how is read JSON into my listview in my app. The result is processed to my app in an average of 3 seconds on Wi-Fi and 5 seconds on 3G:
public class CoreTeamFragment extends ListFragment {
ArrayList> membersList;
private String url_all_leaders = //URL goes here
private ProgressDialog pDialog;
JSONParser jParser = new JSONParser();
// JSON Node names
private static final String CONNECTION_STATUS = "success";
private static final String TABLE_TEAM = "CoreTeam";
private static final String pid = "pid";
private static final String COL_NAME = "CoreTeam_Name";
private static final String COL_DESC = "CoreTeam_Desc";
private static final String COL_PIC = "CoreTeam_Picture";
JSONArray CoreTeam = null;
public static final String ARG_SECTION_NUMBER = "section_number";
public CoreTeamFragment() {
}
public void onStart() {
super.onStart();
membersList = new ArrayList<HashMap<String, String>>();
new LoadAllMembers().execute();
// selecting single ListView item
ListView lv = getListView();
// Lauching the Event details screen on selecting a single event
lv.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String ID = ((TextView) view.findViewById(R.id.leader_id))
.getText().toString();
Intent intent = new Intent(view.getContext(),
CoreTeamDetails.class);
intent.putExtra(pid, ID);
view.getContext().startActivity(intent);
}
});
}
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_coreteam,
container, false);
return rootView;
}
class LoadAllMembers extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
#Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(getActivity());
pDialog.setMessage("Just a moment...");
pDialog.setIndeterminate(true);
pDialog.setCancelable(true);
pDialog.show();
}
protected String doInBackground(String... args) {
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
// getting JSON string from URL
JSONObject json = jParser.makeHttpRequest(url_all_leaders,
"GET", params);
try {
// Checking for SUCCESS TAG
int success = json.getInt(CONNECTION_STATUS);
if (success == 1) {
// products found
// Getting Array of Products
CoreTeam = json.getJSONArray(TABLE_TEAM);
// looping through All Contacts
for (int i = 0; i < CoreTeam.length(); i++) {
JSONObject ct = CoreTeam.getJSONObject(i);
// Storing each json item in variable
String id = ct.getString(pid);
String name = ct.getString(COL_NAME);
String desc = ct.getString(COL_DESC);
String pic = ct.getString(COL_PIC);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(pid, id);
map.put(COL_NAME, name);
map.put(COL_DESC, desc);
map.put(COL_PIC, pic);
// adding HashList to ArrayList
membersList.add(map);
}
} else {
// Options are not available or server is down.
// Dismiss the loading dialog and display an alert
// onPostExecute
pDialog.dismiss();
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
protected void onPostExecute(String file_url) {
// dismiss the dialog after getting all products
pDialog.dismiss();
// updating UI from Background Thread
getActivity().runOnUiThread(new Runnable() {
public void run() {
ListAdapter adapter = new SimpleAdapter(
getActivity(),
membersList,
R.layout.coreteam_item,
new String[] { pid, COL_NAME, COL_DESC, COL_PIC },
new int[] { R.id.leader_id, R.id.leaderName,
R.id.photo });
setListAdapter(adapter);
}
});
}
}
}

Use Volley or Retrofit lib.
Those lib are increasing the speed.
Volley:
JsonObjectRequest channels = new JsonObjectRequest(Method.POST,
Constants.getaccountstatement + Constants.key, statement_object,
new Response.Listener<JSONObject>() {
#Override
public void onResponse(JSONObject arg0) {
}, new Response.ErrorListener()
{
#Override
public void onErrorResponse(VolleyError e) {
Toast.makeText(context, "Error", Toast.LENGTH_SHORT).show();
}

CallBack gives a NullPointException

I'm trying to make a simple webreader work in an AsyncTast,
main thread
public class main extends Activity implements CallBackListener{
...
WebReader wr = new WebReader();
wr.execute("http://www.google.com");
...
#Override
public void callback(String res)
{
Log.e("eee",res);
}
...
}
...
interface CallBackListener
{
void callback(String res);
}
and webreader
class WebReader extends AsyncTask<String, Void, String>{
CallBackListener mListener;
public void setListener(CallBackListener listener){
mListener = listener;
}
#Override
protected String doInBackground(String... urls) {
String response = "";
DefaultHttpClient client = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(urls[0]);
try {
HttpResponse execute = client.execute(httpGet);
InputStream content = execute.getEntity().getContent();
BufferedReader buffer = new BufferedReader(
new InputStreamReader(content));
String s = "";
while ((s = buffer.readLine()) != null) {
response += s;
}
} catch (Exception e) {
e.printStackTrace();
}
return response;
}
#Override
protected void onPostExecute(String result) {
Log.e("s3","ss"+result);
mListener.callback(result); // null point here
}
}
yet it crashed with a nullpoint at mListener.callback ... any ideas what might be wrong?
Thanks!

You are not setting a listener. You should have something like this:
WebReader wr = new WebReader();
wr.setListener( new YourCallbackListener() );
wr.execute("http://www.google.com");

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