Develop Reference

Static variable doesn't change and get replaced with " "

My app is a game that is a simple words puzzle, so the levels on it is fetched from a Json web service, using AsyncTask class I can fetch the data in doInBackground and onPostExecute methods, I use local variables in FetchData class to hold the fetched data in, the data is simply 6 strings that are an image URL and level id, and 4 words that is for the buttons, here is the game interface, as you can see there are 4 buttons each one has a word and the player must find it by looking at the picture.
So when the player finds for example 1 word and leaves the app and closes it, the word the player found must be saved and when he return back to LevelActivity he is supposed to continue the level by finding more 3 words.
THE PROBLEM: is that when I find a word and the word shows (so it must be saved) when I close the app and return this happens, depending on my testing I found out that those lines of code that effects the data lag
NOTE: That whenever I reload the activity (manually) everything gets good and instead of having an empty button after recreating the activity the word shows.
data fetching method used: in onCreate & onResume
//This is in LevelActivity.java:
//These methods checks if the button is answered previously or not (button1/button2... variables are true when a word is answered)
public void checkButton1() {
if (button1) {
wordButton1.setText(button1Word); //<--- Here if I changed it to .setText("Test")
//the lag will disappear and the button will show "Test" (without the quotation) and everything's good
//So the problem is when I use .setText(button1Word); that is the word fetched from Json web service.
//it doesn't throw NullPointerException and it doesn't show the word
//but what? it set the text to " "? Why?
//Note other buttons are the same thing too
}
}
public void checkButton2() {
if (button2) {
wordButton2.setText(button2Word);
}
}
public void checkButton3() {
if (button3) {
wordButton3.setText(button3Word);
}
}
public void checkButton4() {
if (button4) {
wordButton4.setText(button4Word);
}
}
//This is FetchData class that fetches the data from Json web service (full code)
package com.example.wordspuzzlejsontest;
import android.content.Context;
import android.os.AsyncTask;
import com.squareup.picasso.Picasso;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
public class FetchData extends AsyncTask<Void, Void, Void> {
//Local variable that are used to hold fetched data to transfer them to LevelActivity with static variables
static int currentLevel = 0;
String w1;
String w2;
String w3;
String w4;
String data = "";
String id;
String img;
Context context;
#Override
protected Void doInBackground(Void... voids) {
try {
URL url = new URL("https://api.jsonbin.io/b/5e42776dd18e4016617690ce/7");
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
InputStream inputStream = httpURLConnection.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
String line = "";
while (line != null) {
line = bufferedReader.readLine();
data = data + line;
}
JSONArray JA = new JSONArray(data);
JSONObject JO = (JSONObject) JA.get(currentLevel);
id = (String) JO.get("id");
img = (String) JO.get("img");
w1 = (String) JO.get("w1");
w2 = (String) JO.get("w2");
w3 = (String) JO.get("w3");
w4 = (String) JO.get("w4");
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(Void aVoid) {
super.onPostExecute(aVoid);
int levelId = Integer.parseInt(id);
levelId++;
//Loading the words data to buttons
LevelActivity.levelID = String.valueOf(levelId);
LevelActivity.imageURL = img;
LevelActivity.button1Word = w1;
LevelActivity.button2Word = w2;
LevelActivity.button3Word = w3;
LevelActivity.button4Word = w4;
//Loading level image and level number on the screen
LevelActivity.levelIdTextView.setText(LevelActivity.levelID);
loadLevelImage();
}
public void loadLevelImage() {
Picasso.with(context).load(LevelActivity.imageURL).placeholder(R.drawable.loading)
.error(R.drawable.loading)
.into(LevelActivity.imageView, new com.squareup.picasso.Callback() {
#Override
public void onSuccess() {
}
#Override
public void onError() {
}
});
}
}
Thanks for viewing my answer :D tell me if you need any other code.

At the end of onPostExecute() calls to
checkButton1()
checkButton2()
checkButton3()
checkButton4()
are missing. Because of that, buttons cannot know about the new values and therefore remain empty.

"android.os.NetworkOnMainThreadException" even when running in AsyncTask

I'm getting the android.os.NetworkOnMainThreadException error even when I'm running the code inside AsyncTask thread. This is basically just a chunk of code that should return me a value from a website.
package com.jasperhonkasalo.merenpinnankorkeusvsa;
import android.os.AsyncTask;
import android.util.Log;
import org.w3c.dom.Document;
import org.xml.sax.InputSource;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.StringReader;
import java.net.URL;
import java.util.Iterator;
import javax.xml.namespace.NamespaceContext;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathFactory;
public class NewBackgroundTask {
public static class BackgroundTask extends AsyncTask<String, Void, String> {
String value = "presetvalue";
#Override
protected String doInBackground(String... urls) {
class NamespaceResolver implements NamespaceContext {
private Document document;
public NamespaceResolver(Document doc) {
document = doc;
}
public String getNamespaceURI(String prefix) {
if (prefix.equals("")) {
return document.lookupNamespaceURI(null);
} else {
return document.lookupNamespaceURI(prefix);
}
}
public String getPrefix(String namespaceURI) {
return document.lookupPrefix(namespaceURI);
}
public Iterator<String> getPrefixes(String namespaceURI) {
return null;
}
}
try {
String url = "http://opendata.fmi.fi/wfs/fin?service=WFS&version=2.0.0&request=GetFeature&storedquery_id=fmi::observations::mareograph::timevaluepair&fmisid=134223&";
StringBuilder sb = new StringBuilder();
try (BufferedReader r = new BufferedReader(new InputStreamReader(new URL(url).openStream(), "UTF-8"))) {
String line;
while ((line = r.readLine()) != null) {
sb.append(line + "\n");
}
}
String xml = sb.toString();
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
factory.setNamespaceAware(true);
Document document = factory.newDocumentBuilder().parse(new InputSource(new StringReader(xml)));
XPath xpath = XPathFactory.newInstance().newXPath();
xpath.setNamespaceContext(new NamespaceResolver(document));
String time = xpath.evaluate("//wml2:MeasurementTimeseries[#gml:id='obs-obs-1-1-WATLEV']/wml2:point[last()]//wml2:time", document);
value = xpath.evaluate("//wml2:MeasurementTimeseries[#gml:id='obs-obs-1-1-WATLEV']/wml2:point[last()]//wml2:value", document);
System.out.format("time = %s; value = %s\n", time, value);
return value;
} catch (Exception e) {
Log.d("EXCEPTIONFAIL", e.toString());
return "FAIL: " + e.toString();
}
}
#Override
protected void onPostExecute(String feed) {
// TODO: do something with the feed
}
}
}
I'm getting the value with:
static String eeee = new NewBackgroundTask.BackgroundTask().value;
The value of "value"- variable is staying the same (presetvalue) and also giving me a android.os.NetworkOnMainThreadException error. I'm really new to any java programming and would appreciate any help.

You need to execute the AsyncTask, you cannot simply access a static field of it and expect it to give you any result. You need to do something like that:
new BackgroundTask().execute();
Since this is an asynchronous call, it cannot return a result directly (that's what asynchronous means). Instead, you get the result in the onPostExecute() method, which is executed in the main thread.
If you are really completely new to Java programming, you should perhaps not start with asynchronous method calls. That's something, even experienced developers have sometimes problems with.

Android: Sort JSON

New to using REST API and JSON files, but I have retrieved data from a weather API about my current locations weather conditions. The JSON file has data, such as my location, weather speed etc. I wish to sort all these individual parts of data into textViews so they can be clearly seen.
My Asynch Class:
import android.app.Activity;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.os.AsyncTask;
import java.util.ArrayList;
import android.widget.*;
import java.util.Date;
import android.util.Log;
public class RESTAPI extends Activity {
ArrayList<String> items = new ArrayList<String>();
// json test string
String jsonTest;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_restapi);
// start the AsyncTask for calling the REST service using httpConnect class
new AsyncTaskParseJson().execute();
}
// added asynctask class methods below - you can make this class as a separate class file
public class AsyncTaskParseJson extends AsyncTask<String, String, String> {
// set the url of the web service to call
String yourServiceUrl = "http://api.apixu.com/v1/current.json?key=e87e62510df946cc84c02652162112&q=LN11RX";
#Override
protected void onPreExecute() {
}
#Override
protected String doInBackground(String... arg0) {
try {
// create new instance of the httpConnect class
httpConnect jParser = new httpConnect();
// get json string from service url
String json = jParser.getJSONFromUrl(yourServiceUrl);
// save returned json to your test string
jsonTest = json.toString();
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(String strFromDoInBg) {
TextView tv1 = (TextView) findViewById(R.id.jsontext);
tv1.setText(jsonTest);
}
}
}
My httpConnect Class to handle the URL:
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import android.util.Log;
public class httpConnect {
final String TAG = "JsonParser.java";
static String json = "";
public String getJSONFromUrl(String url) {
try {
URL u = new URL(url);
HttpURLConnection restConnection = (HttpURLConnection) u.openConnection();
restConnection.setRequestMethod("GET");
restConnection.setRequestProperty("Content-length", "0");
restConnection.setUseCaches(false);
restConnection.setAllowUserInteraction(false);
restConnection.setConnectTimeout(10000);
restConnection.setReadTimeout(10000);
restConnection.connect();
int status = restConnection.getResponseCode();
// switch statement to catch HTTP 200 and 201 errors
switch (status) {
case 200:
case 201:
BufferedReader br = new BufferedReader(new InputStreamReader(restConnection.getInputStream()));
// create a new string builder to store json data returned from the REST service
StringBuilder sb = new StringBuilder();
String line;
// loop through returned data line by line and append to stringbuilder 'sb' variable
while ((line = br.readLine()) != null) {
sb.append(line+"\n");
}
br.close();
try {
json = sb.toString();
} catch (Exception e) {
Log.e(TAG, "Error parsing data " + e.toString());
}
return json;
}
// HTTP 200 and 201 error handling from switch statement
} catch (MalformedURLException ex) {
Log.e(TAG, "Malformed URL ");
} catch (IOException ex) {
Log.e(TAG, "IO Exception ");
}
return null;
}
So is there anyway to sort the returned data and put each bit of data into its own textbox?
Screenshot of JSON:

If I am understanding your question correctly, try giving this link a go. Let me know if I have misunderstood and I will try and help you with an alternative.
Edit:
Roughly another way to dynamically create new a new TextView and set data:
TextView view;
LinearLayout currLayout = (LinearLayout) findViewById(R.id.LinearLayout);
for(String value : items) {
view = new TextView();
view.setText(value);
currLayout.addView(view);
}

Make pojo classes for the response you get:
Open any converting site like this:-
http://www.jsonschema2pojo.org/
here paste the json reponse, and click zip, all pojo class will be automatically created for you.
Now in your code do this
protected String doInBackground(String... arg0) {
try {
// create new instance of the httpConnect class
httpConnect jParser = new httpConnect();
// get json string from service url
String json = jParser.getJSONFromUrl(yourServiceUrl);
// save returned json to your test string
jsonTest = json.toString();
Gson gson = new Gson();
/*here Example class is the main pojo class, you can use this class which will be there in the zip, which is created from jsontoPojo converting site */
Example response = gson.fromJson(json, Example.class);
/*
*Now to get data
* just do this */
String name = getLocation().getName();
.
.
.
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
For details view this example,example of data parsing using gson
And you need to add this dependency as well in build.gradle file
compile 'com.google.code.gson:gson:2.4'

Asynchronous HTTP call doesn't work

I am working on an Android app (min API 8) and I want to make an activity where there is a preloader GIF running while some tasks are executed in the background.
These tasks involve connection to a database and queries. So in some way, I want to achieve something that involves techniques like you would use to make a progress bar.
I know I can't make a connection in the main thread in Java so I made a class that does this in another thread. The connection works fine, but I can't make the whole behaviour work properly. More precisely, if I use thread.join()then the main thread is blocked (which is the opposite of what I want) and if I don't use it, the code of the main thread goes on and finishes before the background process has terminated.
Can someone help me with this please ?
This is the class I created to manage POST queries to an URL :
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLEncoder;
import java.util.concurrent.atomic.AtomicReference;
public class Request
{
private URL m_url;
private StringBuilder m_parameters;
private HttpURLConnection m_connection;
public Request(String url)
{
try
{
m_url = new URL(url);
}
catch(MalformedURLException exception)
{
System.exit(1);
}
m_connection = null;
m_parameters = new StringBuilder();
}
public void put(String key, String value)
{
if(m_parameters.length() != 0)
m_parameters.append('&');
try
{
m_parameters.append(URLEncoder.encode(key, "UTF-8"));
m_parameters.append('=');
m_parameters.append(URLEncoder.encode(value, "UTF-8"));
}
catch(UnsupportedEncodingException exception)
{
System.exit(1);
}
}
private void sendRequest()
{
try
{
byte[] data = m_parameters.toString().getBytes("UTF-8");
m_connection = (HttpURLConnection) m_url.openConnection();
m_connection.setAllowUserInteraction(true);
m_connection.setRequestMethod("POST");
m_connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded;charset=utf-8");
m_connection.setRequestProperty("Content-Length", String.valueOf(data.length));
m_connection.setDoOutput(true);
m_connection.getOutputStream().write(data);
}
catch(Exception exception)
{
System.exit(1);
}
}
private String getResponse()
{
String response = "";
try
{
if(m_connection.getResponseCode() == HttpURLConnection.HTTP_OK)
{
Reader reader = new BufferedReader(new InputStreamReader(m_connection.getInputStream(), "UTF-8"));
int c;
do {
c = reader.read();
response += (char) c;
}
while (c >= 0);
}
}
catch(IOException exception)
{
System.exit(1);
}
m_connection.disconnect();
return response;
}
public String get()
{
final AtomicReference<String> response = new AtomicReference<>();
Thread thread = new Thread(new Runnable()
{
public void run()
{
sendRequest();
response.set(getResponse());
}
});
thread.start();
/*
try
{
thread.join();
}
catch(InterruptedException exception)
{
System.exit(1);
}
*/
return response.get();
}
}
And this is how I use it in the main thread (the activity) :
Request request = new Request("http://posttestserver.com/post.php?dump&html&sleep=5");
request.put("name", "bob");
String response = request.get();
Thanks.

Okay, I finally solved that problem using standard IntentServiceof Android :
https://developer.android.com/training/run-background-service/create-service.html
This tutorial helped a lot too :
http://code.tutsplus.com/tutorials/android-fundamentals-intentservice-basics--mobile-6183
Here is my new class Request:
import android.app.IntentService;
import android.content.Intent;
import android.os.Bundle;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLEncoder;
import java.util.Set;
public class Request extends IntentService
{
private URL m_url;
private StringBuilder m_parameters;
private HttpURLConnection m_connection;
public Request()
{
super("Request");
m_url = null;
m_connection = null;
m_parameters = new StringBuilder();
}
public void put(String key, String value)
{
if(m_parameters.length() != 0)
m_parameters.append('&');
try
{
m_parameters.append(URLEncoder.encode(key, "UTF-8"));
m_parameters.append('=');
m_parameters.append(URLEncoder.encode(value, "UTF-8"));
}
catch(UnsupportedEncodingException exception)
{
System.exit(1);
}
}
private void sendRequest()
{
try
{
byte[] data = m_parameters.toString().getBytes("UTF-8");
m_connection = (HttpURLConnection) m_url.openConnection();
m_connection.setAllowUserInteraction(true);
m_connection.setRequestMethod("POST");
m_connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded;charset=utf-8");
m_connection.setRequestProperty("Content-Length", String.valueOf(data.length));
m_connection.setDoOutput(true);
m_connection.getOutputStream().write(data);
}
catch(Exception exception)
{
System.exit(1);
}
}
private String getResponse()
{
String response = "";
try
{
if(m_connection.getResponseCode() == HttpURLConnection.HTTP_OK)
{
Reader reader = new BufferedReader(new InputStreamReader(m_connection.getInputStream(), "UTF-8"));
int c;
do {
c = reader.read();
response += (char) c;
}
while (c >= 0);
}
}
catch(IOException exception)
{
System.exit(1);
}
m_connection.disconnect();
return response;
}
protected void onHandleIntent(Intent intent)
{
Bundle bundle = intent.getExtras();
Set<String> keys = bundle.keySet();
for(String key : keys)
put(key, bundle.getString(key));
try
{
m_url = new URL(bundle.getString("url"));
}
catch(MalformedURLException exception)
{
System.exit(1);
}
sendRequest();
String response = getResponse();
Intent broadcast = new Intent();
broadcast.setAction(ReadyActivity.ResponseReceiver.m_broadcastKey);
broadcast.putExtra("response", response);
sendBroadcast(broadcast);
}
}
Here is the ResponseReceiversubclass of my main activity :
public class ResponseReceiver extends BroadcastReceiver
{
public static final String m_broadcastKey = "Uz258e3wZm77Z3Tdebn7PqgW3CLBJ8";
public void onReceive(Context context, Intent intent)
{
String response = intent.getStringExtra("response");
clear();
((TextView) m_widgets.get("text")).setText("Finally found someone !" + response);
show(m_widgets.get("text"));
((Button) m_widgets.get("button1")).setText("OK let's do this !");
show(m_widgets.get("button1"));
((Button) m_widgets.get("button2")).setText("Later ?");
show(m_widgets.get("button2"));
unregisterReceiver(m_receiver);
}
}
Then I also had to instantiate the ResponseReceiver in the activity:
private ResponseReceiver m_receiver;
...
IntentFilter filter = new IntentFilter(ResponseReceiver.m_broadcastKey);
m_receiver = new ResponseReceiver();
registerReceiver(m_receiver, filter);
And finally call the service :
Intent service = new Intent(this, Request.class);
ArrayList<CharSequence> parameters = new ArrayList<>();
service.putExtra("url", "http://posttestserver.com/post.php?dump&html&sleep=10");
service.putExtra("username", "bob");
service.putExtra("age", "20");
startService(service);
Maybe it will help someone in the future.

Why does this Java app fail to show JSON data on refresh?

This is a mobile app composed in Java with Codename One's CODAPPS plugin for NetBeans IDE.
The code is from a Coursera course where a Twitter-clone app was developed. In the course the coding of the app was show, but the end result -- a wall of "Roars" (Tweets) which appears when you click Refresh -- was not shown, and does not appear to work.
There are no errors, but I simply cannot get it to display any Roars (Tweets). These are downloaded as JSON data. I confirmed that the data uploads and downloads as it should; it's just not displaying.
All of the user-written code is stored in a file called StateMachine.java. I will paste this code below. The entire project is also available here on GitHub.
/**
* Your application code goes here
*/
package userclasses;
import com.codename1.analytics.AnalyticsService;
import com.codename1.io.ConnectionRequest;
import com.codename1.io.NetworkManager;
import com.codename1.io.Preferences;
import com.codename1.io.Util;
import com.codename1.processing.Result;
import generated.StateMachineBase;
import com.codename1.ui.*;
import com.codename1.ui.events.*;
import com.codename1.ui.layouts.BoxLayout;
import com.codename1.ui.layouts.Layout;
import com.codename1.ui.util.Resources;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Hashtable;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
/**
*
* #author Your name here
*/
public class StateMachine extends StateMachineBase {
String roar;
public StateMachine(String resFile) {
super(resFile);
// do not modify, write code in initVars and initialize class members there,
// the constructor might be invoked too late due to race conditions that might occur
}
/**
* this method should be used to initialize variables instead of the
* constructor/class scope to avoid race conditions
*/
protected void initVars(Resources res) {
AnalyticsService.init("UA-67803686-1", "irrelevant");
AnalyticsService.setAppsMode(true);
}
#Override
protected void onMain_ButtonAction(Component c, ActionEvent event) {
Hashtable infoToBeSent = new Hashtable();
infoToBeSent.put("roar", roar);
infoToBeSent.put("author", "seinecle");
final String infoInString = Result.fromContent(infoToBeSent).toString();
String firebase = "https://roar.firebaseIO.com/listofroars.json";
ConnectionRequest request = new ConnectionRequest() {
#Override
protected void buildRequestBody(OutputStream os) throws IOException {
os.write(infoInString.getBytes("UTF-8"));
}
};
request.setUrl(firebase);
request.setPost(true);
request.setHttpMethod("POST");
request.setContentType("application/json");
NetworkManager.getInstance().addToQueueAndWait(request);
}
#Override
protected void onMain_TextAreaAction(Component c, ActionEvent event) {
roar = findTextArea().getText();
if (roar == null) {
roar = "we did not get a roar from you";
}
}
#Override
protected void onWall_ButtonAction(Component c, ActionEvent event) {
try {
String roars = "https://roar.firebaseIO.com/listofroars.json";
//if we want to retrieve only the latest 10 roars posted
//String roars = "https://roar.firebaseIO.com/listofroars.json" + "?" + "orderBy=\"$key\"" + "&" + "limitToLast=10";
ConnectionRequest request = new ConnectionRequest();
request.setUrl(roars);
request.setPost(false);
request.setHttpMethod("GET");
request.setContentType("application/json");
NetworkManager.getInstance().addToQueueAndWait(request);
ByteArrayInputStream allRoarsInBytes = new ByteArrayInputStream(request.getResponseData());
String responseInString = Util.readToString(allRoarsInBytes, "UTF-8");
JSONObject allRoarsInJsonFormat = new JSONObject(responseInString);
JSONArray listOfRoarIds = allRoarsInJsonFormat.names();
Form wallScreen = c.getComponentForm();
Container myContainerForAllRoars = new Container();
Layout myLayout = new BoxLayout(BoxLayout.Y_AXIS);
myContainerForAllRoars.setLayout(myLayout);
Integer counterOfRoars = 0;
while (counterOfRoars < allRoarsInJsonFormat.length()) {
String idOfOneRoar = listOfRoarIds.getString(counterOfRoars);
JSONObject oneRoarInJsonFormat = (JSONObject) allRoarsInJsonFormat.get(idOfOneRoar);
Container myRoarContainer = new Container();
String author = oneRoarInJsonFormat.getString("author");
String roarText = oneRoarInJsonFormat.getString("roar");
Label myLabelForAuthor = new Label(author);
Label myLabelForRoar = new Label(roarText);
myRoarContainer.addComponent(myLabelForAuthor);
myRoarContainer.addComponent(myLabelForRoar);
myContainerForAllRoars.addComponent(myRoarContainer);
counterOfRoars = counterOfRoars + 1;
}
wallScreen.addComponent(wallScreen.getComponentCount(), myContainerForAllRoars);
wallScreen.revalidate();
} catch (IOException ex) {
} catch (JSONException ex) {
}
}
#Override
protected void onCreateUserName() {
String userName;
userName = Preferences.get("username", "");
if (userName != null) {
showForm("Main", null);
AnalyticsService.visit("Main", "UserName");
}
}
#Override
protected void onUserName_ButtonAction(Component c, ActionEvent event) {
String userName = findTextField().getText();
if (userName == null || userName.length() == 0) {
} else {
Preferences.set("username", userName);
showForm("Main", null);
AnalyticsService.visit("Main", "UserName");
}
}
}
I tried adding wallScreen.show() and Wall.show() but it didn't fix the problem.

Just add the following code and it works well on both connections
request.setDuplicateSupported(true);