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RuntimeException by using Google Youtube Api v3 in my android app

I want to get the list of videos from Youtube channel.
You will see below the class to connect to Youtube and my Activity that interacts with this class. I get an exception "java.lang.RuntimeException: Unable to start activity VideoListActivity" when calling YouTube.Search.List.execute();
I am new in android, so I think there is a stupid mistake. Please help to find it, or maybe suggest the another way to get data from Youtube.
YoutubeConnector class
import com.google.api.client.http.HttpRequest;
import com.google.api.client.http.HttpRequestInitializer;
import com.google.api.client.http.javanet.NetHttpTransport;
import com.google.api.client.json.jackson2.JacksonFactory;
import com.google.api.services.youtube.YouTube;
import com.google.api.services.youtube.model.SearchListResponse;
import com.google.api.services.youtube.model.SearchResult;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
public class YoutubeConnector {
private static YouTube youtube;
private static YouTube.Search.List query;
public static final String KEY = DeveloperKey.DEVELOPER_KEY;
public static List<VideoItem> search() throws IOException {
youtube = new YouTube.Builder(new NetHttpTransport(), new JacksonFactory(), new HttpRequestInitializer() {
#Override
public void initialize(HttpRequest httpRequest) throws IOException {
}
}).setApplicationName(R.string.app_name).build();
query = youtube.search().list("id,snippet");
query.setKey(KEY);
query.setType("video");
query.setChannelId("**************");
query.setFields("items(id/videoId,snippet/title,snippet/description,snippet/thumbnails/default/url)");
SearchListResponse response = query.execute();
List<SearchResult> results = response.getItems();
List<VideoItem> items = new ArrayList<VideoItem>();
for (SearchResult result : results) {
VideoItem item = new VideoItem();
item.setTitle(result.getSnippet().getTitle());
item.setDescription(result.getSnippet().getDescription());
item.setThumbnailURL(result.getSnippet().getThumbnails().getDefault().getUrl());
item.setId(result.getId().getVideoId());
items.add(item);
}
return items;
}
}
VideoListActivity class
public class VideoListActivity extends ListActivity{
List<VideoItem> videoFileList;
public class VideoAapter extends ArrayAdapter{
//.....................
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
try {
videoFileList = YoutubeConnector.search();
} catch (IOException e) {
e.printStackTrace();
}
setListAdapter(new VideoAapter(VideoListActivity.this, R.layout.list_item_video, videoFileList));
}
}
Logcat
06-16 18:14:56.926 30817-30817/com.example.alex.youtubecanal W/art: Failed to find OatDexFile for DexFile /data/data/com.example.alex.youtubecanal/files/instant-run/dex/slice-slice_5-classes.dex ( canonical path /data/data/com.example.alex.youtubecanal/files/instant-run/dex/slice-slice_5-classes.dex) with checksum 0x7eb43558 in OatFile /data/data/com.example.alex.youtubecanal/cache/slice-slice_5-classes.dex
06-16 18:14:57.631 30817-30817/com.example.alex.youtubecanal I/System.out: (HTTPLog)-Static: isSBSettingEnabled false
06-16 18:14:57.631 30817-30817/com.example.alex.youtubecanal I/System.out: (HTTPLog)-Static: isShipBuild true
06-16 18:14:57.631 30817-30817/com.example.alex.youtubecanal I/System.out: (HTTPLog)-Thread-1-786658172: SmartBonding Enabling is false, SHIP_BUILD is true, log to file is false, DBG is false
06-16 18:14:57.631 30817-30817/com.example.alex.youtubecanal I/System.out: (HTTPLog)-Thread-1-786658172: SMARTBONDING_FEATURE_ENABLED is false
06-16 18:14:57.636 30817-30817/com.example.alex.youtubecanal I/System.out: (HTTPLog)-Static: isSBSettingEnabled false
06-16 18:14:57.636 30817-30817/com.example.alex.youtubecanal I/System.out: KnoxVpnUidStorageknoxVpnSupported API value returned is false
06-16 18:14:57.636 30817-30817/com.example.alex.youtubecanal D/AndroidRuntime: Shutting down VM
06-16 18:14:57.641 30817-30817/com.example.alex.youtubecanal E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.alex.youtubecanal, PID: 30817
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.alex.youtubecanal/com.example.alex.youtubecanal.VideoListActivity}: android.os.NetworkOnMainThreadException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3133)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3243)
at android.app.ActivityThread.access$1000(ActivityThread.java:218)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1718)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:145)
at android.app.ActivityThread.main(ActivityThread.java:6917)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1404)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1199)
Caused by: android.os.NetworkOnMainThreadException
at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1147)
at java.net.InetAddress.lookupHostByName(InetAddress.java:418)
at java.net.InetAddress.getAllByNameImpl(InetAddress.java:252)
at java.net.InetAddress.getAllByName(InetAddress.java:215)
at com.android.okhttp.HostResolver$1.getAllByName(HostResolver.java:29)
at com.android.okhttp.internal.http.RouteSelector.resetNextInetSocketAddress(RouteSelector.java:245)
at com.android.okhttp.internal.http.RouteSelector.next(RouteSelector.java:128)
at com.android.okhttp.internal.http.HttpEngine.connect(HttpEngine.java:370)
at com.android.okhttp.internal.http.HttpEngine.sendRequest(HttpEngine.java:298)
at com.android.okhttp.internal.http.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:399)
at com.android.okhttp.internal.http.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:110)
at com.android.okhttp.internal.http.DelegatingHttpsURLConnection.connect(DelegatingHttpsURLConnection.java:89)
at com.android.okhttp.internal.http.HttpsURLConnectionImpl.connect(HttpsURLConnectionImpl.java:25)
at com.google.api.client.http.javanet.NetHttpRequest.execute(NetHttpRequest.java:93)
at com.google.api.client.http.HttpRequest.execute(HttpRequest.java:981)
at com.google.api.client.googleapis.services.AbstractGoogleClientRequest.executeUnparsed(AbstractGoogleClientRequest.java:419)
at com.google.api.client.googleapis.services.AbstractGoogleClientRequest.executeUnparsed(AbstractGoogleClientRequest.java:352)
at com.google.api.client.googleapis.services.AbstractGoogleClientRequest.execute(AbstractGoogleClientRequest.java:469)
at com.example.alex.youtubecanal.YoutubeConnector.search(YoutubeConnector.java:37)
at com.example.alex.youtubecanal.VideoListActivity.onCreate(VideoListActivity.java:58)
at android.app.Activity.performCreate(Activity.java:6609)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1134)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3086)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3243) 
at android.app.ActivityThread.access$1000(ActivityThread.java:218) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1718) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:145) 
at android.app.ActivityThread.main(ActivityThread.java:6917) 
at java.lang.reflect.Method.invoke(Native Method) 
at java.lang.reflect.Method.invoke(Method.java:372) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1404) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1199) 

You need to run the YoutubeConnector.search outside of onCreate() in an Async Thread. This basically means that the method is stalling the program and will cause the program to crash or hang. To fix, create a new class called Search for example:
SearchClass.java:
import android.os.AsyncTask;
import java.io.IOException;
public class Search extends AsyncTask<String, Void, Void> {
#Override
protected Void doInBackground(String... params) {
try {
videoFileList = YoutubeConnector.search();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(String a){
VideoListActivity.context.updateAdapter();
}
}
VideoListActivity.java:
public class VideoListActivity extends ListActivity{
static List<VideoItem> videoFileList;
static Context context;
public class VideoAapter extends ArrayAdapter{
//.....................
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Search search= new Search();
search.execute(new String[]{});
}
public void updateAdapter(ArrayList<String> list) {
setListAdapter(new VideoAapter(VideoListActivity.this,R.layout.list_item_video, videoFileList));
}
}
Hopefully this will work :). If it does not, just post the error, and we'll get back. Good luck!

It looks like the problem is coming from a NetworkOnMainThreadException. Check out this example. Hope it helps!

AsyncTask task onPostExecute() not executing? Tried all answer already present on stackoverflow

Hi Developers and friends,
I am working on an android application, which required to read JSON url. I am using AsyncTask. But I dont know why the onPostExecute() is not executing. I successfully parse the json. The only thing left is to return the string (having parse json text).
Here is my code:
package com.vijay.jsonwizard.demo.activities;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.view.View;
import android.widget.Toast;
import com.squareup.okhttp.OkHttpClient;
import com.squareup.okhttp.Request;
import com.squareup.okhttp.Response;
import com.vijay.jsonwizard.demo.R;
import com.vijay.jsonwizard.activities.JsonFormActivity;
import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends ActionBarActivity {
private static final int REQUEST_CODE_GET_JSON = 1;
private static final String TAG = "MainActivity";
private static final String DATA_JSON_PATH = "http://jatinderbhola.in/phppractice/data.json";
String json;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
findViewById(R.id.button_start).setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(MainActivity.this, JsonFormActivity.class);
BackgroundTask task = new BackgroundTask();
task.execute();
if (json != null) {
intent.putExtra("json", json);
startActivityForResult(intent, REQUEST_CODE_GET_JSON);
} else {
Toast.makeText(getApplicationContext(), "Error!!", Toast.LENGTH_LONG).show();
}
}
});
}
private class BackgroundTask extends AsyncTask < String, String, String > {
#Override
protected void onPreExecute() {
super.onPreExecute();
}
#Override
protected String doInBackground(String...params) {
OkHttpClient client = new OkHttpClient();
Request request = new Request.Builder()
.url(DATA_JSON_PATH)
.build();
Response response = null;
try {
response = client.newCall(request).execute();
} catch (IOException e) {
e.printStackTrace();
}
try {
//Log.d("Respose", response.body().string());
return response.body().string();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(String data) {
set_json(data);
}
}
private void set_json(String s) {
// json = s;
Toast.makeText(getApplicationContext(), "I'm in!!", Toast.LENGTH_LONG).show();
}
}
Thanks and advance.
no exception:
this is what android monitor displaying:
01-28 13:42:17.117 1450-1450/com.vijay.jsonwizard.demo I/art: Not late-enabling -Xcheck:jni (already on)
01-28 13:42:17.117 1450-1450/com.vijay.jsonwizard.demo I/art: Late-enabling JIT
01-28 13:42:17.119 1450-1450/com.vijay.jsonwizard.demo I/art: JIT created with code_cache_capacity=2MB compile_threshold=1000
01-28 13:42:17.147 1450-1450/com.vijay.jsonwizard.demo W/System: ClassLoader referenced unknown path: /data/app/com.vijay.jsonwizard.demo-1/lib/x86
01-28 13:42:17.309 1450-1477/com.vijay.jsonwizard.demo D/OpenGLRenderer: Use EGL_SWAP_BEHAVIOR_PRESERVED: true
01-28 13:42:17.411 1450-1477/com.vijay.jsonwizard.demo I/OpenGLRenderer: Initialized EGL, version 1.4
01-28 13:42:17.805 1450-1458/com.vijay.jsonwizard.demo W/art: Suspending all threads took: 31.806ms
01-28 13:42:17.935 1450-1477/com.vijay.jsonwizard.demo W/EGL_emulation: eglSurfaceAttrib not implemented
01-28 13:42:17.935 1450-1477/com.vijay.jsonwizard.demo W/OpenGLRenderer: Failed to set EGL_SWAP_BEHAVIOR on surface 0xad7600e0, error=EGL_SUCCESS
01-28 13:42:17.991 1450-1450/com.vijay.jsonwizard.demo I/Choreographer: Skipped 38 frames! The application may be doing too much work on its main thread.
01-28 13:43:25.890 1450-1458/com.vijay.jsonwizard.demo W/art: Suspending all threads took: 5.563ms
01-28 13:49:09.646 1450-1458/com.vijay.jsonwizard.demo W/art: Suspending all threads took: 6.337ms
01-28 13:56:08.565 1450-1477/com.vijay.jsonwizard.demo W/EGL_emulation: eglSurfaceAttrib not implemented
01-28 13:56:08.566 1450-1477/com.vijay.jsonwizard.demo W/OpenGLRenderer: Failed to set EGL_SWAP_BEHAVIOR on surface 0xad7603e0, error=EGL_SUCCESS
01-28 13:56:11.892 1450-1477/com.vijay.jsonwizard.demo E/Surface: getSlotFromBufferLocked: unknown buffer: 0xb4053c00

move the next code to PostExecute stage:
Intent intent = new Intent(MainActivity.this, JsonFormActivity.class);
if (json != null) {
intent.putExtra("json", json);
startActivityForResult(intent, REQUEST_CODE_GET_JSON);
} else {
Toast.makeText(getApplicationContext(), "Error!!", Toast.LENGTH_LONG).show();
}
}

ASyncTask with progressdialog and button

I am beginner and I had a test. I did all tasks, but I have a problem -
public class HttpTask extends AsyncTask<Integer, String, String> {####
ProgressDialog dialog;
Context context;
public HttpTask(Activity activity) {
//init progress dialog
dialog = new ProgressDialog(context);****
dialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
}
protected void onPreExecute() {
// show progress dialog
dialog.setMessage("Loading...");
dialog.setCancelable(false);
}
protected String doInBackground(Integer... params) {
//freeze system to 5 seconds
try {
int seconds = params[0]*5;####
TimeUnit.SECONDS.sleep(seconds);
} catch (InterruptedException e) {
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(final String success) {
// if there is progress dialog hide it
dialog.dismiss();
}
}
It crashes, when I try to compile it (I showed where are problems with * sign):
08-03 10:43:10.873 29441-29441/? E/AndroidRuntime﹕ FATAL EXCEPTION: main
java.lang.NullPointerException
at android.app.AlertDialog.resolveDialogTheme(AlertDialog.java:142)
at android.app.AlertDialog.<init>(AlertDialog.java:98)
at android.app.ProgressDialog.<init>(ProgressDialog.java:77)
at net.joerichard.androidtest.main.f.HttpTask.<init>(HttpTask.java:26)
at net.joerichard.androidtest.main.f.F_Networking_Activity$1.onClick(F_Networking_Activity.java:27)
at android.view.View.performClick(View.java:4107)
at android.view.View$PerformClick.run(View.java:17166)
at android.os.Handler.handleCallback(Handler.java:615)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:155)
at android.app.ActivityThread.main(ActivityThread.java:5559)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1074)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:841)
at dalvik.system.NativeStart.main(Native Method)
08-03 10:43:10.913 754-877/? E/EmbeddedLogger﹕ App crashed! Process: net.joerichard.androidtest
08-03 10:43:10.913 754-877/? E/EmbeddedLogger﹕ App crashed! Package: net.joerichard.androidtest v1 (1.0)
08-03 10:43:10.913 754-877/? E/EmbeddedLogger﹕ Application Label: AndroidTest
This is class of main activity.
public class F_Networking_Activity extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_f__networking_);
// bDownload: start HttpTask
Button bDownload = (Button) findViewById(R.id.bDownload);
bDownload.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
HttpTask task = new HttpTask(F_Networking_Activity.this);****
task.execute();
}
});
}
Thank you for your answers. Now I have another problem (I showed with # sign of second problems)
08-03 11:28:18.292 754-877/? E/EmbeddedLogger﹕ App crashed! Process: net.joerichard.androidtest'
08-03 11:28:18.292 754-877/? E/EmbeddedLogger﹕ App crashed! Package: net.joerichard.androidtest v1 (1.0)
08-03 11:28:18.292 754-877/? E/EmbeddedLogger﹕ Application Label: AndroidTest
08-03 11:28:18.292 30544-30726/? E/AndroidRuntime﹕ FATAL EXCEPTION: AsyncTask #1
java.lang.RuntimeException: An error occured while executing doInBackground()
at android.os.AsyncTask$3.done(AsyncTask.java:299)
at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273)
at java.util.concurrent.FutureTask.setException(FutureTask.java:124)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307)
at java.util.concurrent.FutureTask.run(FutureTask.java:137)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
at java.lang.Thread.run(Thread.java:864)
Caused by: java.lang.ArrayIndexOutOfBoundsException: length=0; index=0
at net.joerichard.androidtest.main.f.HttpTask.doInBackground(HttpTask.java:40)
at net.joerichard.androidtest.main.f.HttpTask.doInBackground(HttpTask.java:20)
at android.os.AsyncTask$2.call(AsyncTask.java:287)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
at java.util.concurrent.FutureTask.run(FutureTask.java:137)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
at java.lang.Thread.run(Thread.java:864)

Actually, your context is null because you didn't initialize it.
Add one extra line inside your HttpTask:
public HttpTask(Activity activity) {
this.context = activity;
dialog = new ProgressDialog(context);
dialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
}
and change Context to Activity like this:
Activity context;
Now call this context anywhere in your class.

Yes you must get NullPointer. Because your context is null.
Change this like
public HttpTask(Context _context) {
context = _context;
//init progress dialog
dialog = new ProgressDialog(context);****
dialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
}

IBM Worklight - Unable to get network signal strength in Android

Below is my Java implementation. The idea is to display myUtilString in an edit text in order to see the signal strength in a Hybrid android app while in a WL.NativePage, but I get nothing.
I have tested the app on a real device, changing to 2G, 3G and LTE but I don't receive anything. I have implemented a function called onSignalStrengthsChanged, but I cant figure out what is wrong.
In LogCat there is nothing of interest; maybe onSignalStrengthsChanged never is fired.
package com.AndroidShowNativePage;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.app.Activity;
import android.content.Context;
import android.telephony.gsm.GsmCellLocation;
import android.telephony.PhoneStateListener;
import android.telephony.SignalStrength;
import android.telephony.TelephonyManager;
import android.telephony.CellLocation;
import android.webkit.WebView;
public class HelloNative extends Activity {
EditText editText = null;
EditText editText1 = null;
String myUtilString = "";
private TelephonyManager tm ;
private DroidPhoneStateListener listener;
private GsmCellLocation location;
public void GSM(Activity activity, WebView view) {
tm = (TelephonyManager) activity
.getSystemService(Context.TELEPHONY_SERVICE);
listener = new DroidPhoneStateListener(view);
location = new GsmCellLocation();
}
public void listen() {
tm.listen(listener, PhoneStateListener.LISTEN_SIGNAL_STRENGTHS);
//TODO
//tm.listen(listener, PhoneStateListener.LISTEN_SIGNAL_STRENGTH);
//tm.listen(listener, PhoneStateListener.LISTEN_CELL_LOCATION);
//tm.listen(listener, PhoneStateListener.LISTEN_DATA_ACTIVITY);
}
public void unlisten() {
tm.listen(listener, PhoneStateListener.LISTEN_NONE);
}
public int getCid() {
return location.getCid();
}
public int getLac() {
return location.getLac();
}
/*
* ???? public int getPsc() { return location.getPsc(); }
*/
private class DroidPhoneStateListener extends PhoneStateListener {
private WebView view;
DroidPhoneStateListener(WebView view) {
this.view = view;
}
#Override
public void onCellLocationChanged(CellLocation location) {
myUtilString = ( "onCellLocationChanged: " + location.toString());
// view.loadUrl("javascript:droid.Accelerometer.onUpdate();
}
#Override
public void onDataConnectionStateChanged(int state, int networkType) {
myUtilString =( "onDataConnectionStateChanged: " + state + ":" + networkType);
}
#Override
public void onSignalStrengthsChanged(SignalStrength s) {
super.onSignalStrengthsChanged(s);
String r = s.getGsmSignalStrength() + ":" + s.getCdmaDbm() + ":"
+ s.getCdmaEcio() + ":" + s.getEvdoDbm() + ":"
+ s.getEvdoEcio() + ":" + s.getEvdoSnr() + ":"
+ s.getGsmBitErrorRate();
myUtilString = ("hello Change('" + r.toString()+ "');");
}
#Override
public void onSignalStrengthChanged(int asu) {
myUtilString = ( "onSignalStrengthChanged: " + asu);
}
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
String name = getIntent().getStringExtra("nameParam");
LinearLayout linearLayout = new LinearLayout(this);
linearLayout.setOrientation(LinearLayout.VERTICAL);
setContentView(linearLayout);
TextView textView1 = new TextView(this);
textView1.setText("Name received from JavaScript :: " + name);
TextView textView2 = new TextView(this);
textView2.setText("Enter the phone number");
editText = new EditText(this);
editText.setText("1234567890");
editText1 = new EditText(this);
editText1.setText("any measure on dBd");
Button submitButton = new Button(this);
submitButton.setText("Return to the Web App");
submitButton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
String phoneNumber = editText.getText().toString();
Intent phoneNumberInfo = new Intent();
phoneNumberInfo.putExtra("phoneNumber", phoneNumber);
setResult(RESULT_OK, phoneNumberInfo);
finish();
}
});
Button submitMeasure = new Button(this);
submitMeasure.setText("Go measure");
submitMeasure.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
editText1.setText( myUtilString );
}
});
linearLayout.addView(textView1);
linearLayout.addView(textView2);
linearLayout.addView(editText);
linearLayout.addView(submitButton);
linearLayout.addView(submitMeasure);
linearLayout.addView(editText1);
}
}
here is LogCat:
05-08 12:06:30.140: D/SoftKeyboardDetect(1078): Ignore this event
05-08 12:06:31.190: D/WLDroidGap(1078): Started copying files to local storage...
05-08 12:06:48.800: D/dalvikvm(1078): GC_FOR_ALLOC freed 494K, 15% free 3318K/3896K, paused 35ms, total 35ms
05-08 12:06:59.950: D/dalvikvm(1078): GC_FOR_ALLOC freed 370K, 16% free 3319K/3908K, paused 34ms, total 34ms
05-08 12:07:10.540: D/WLDroidGap(1078): Finished copying files to local storage...
05-08 12:07:10.550: D/WLDroidGap(1078): no need to check web resource integrity
05-08 12:07:10.690: D/CordovaWebView(1078): >>> loadUrl(file:///data/data/com.AndroidShowNativePage/files/www/skinLoader.html)
05-08 12:07:10.690: D/PluginManager(1078): init()
05-08 12:07:10.730: D/CordovaWebView(1078): >>> loadUrlNow()
05-08 12:07:12.560: D/CordovaActivity(1078): onMessage(onPageStarted,file:///data/data/com.AndroidShowNativePage/files/www/skinLoader.html)
05-08 12:07:14.610: D/CordovaWebViewClient(1078): onPageFinished(file:///data/data/com.AndroidShowNativePage/files/www/skinLoader.html)
05-08 12:07:14.610: D/CordovaActivity(1078): onMessage(onPageFinished,file:///data/data/com.AndroidShowNativePage/files/www/skinLoader.html)
05-08 12:07:16.650: D/CordovaActivity(1078): onMessage(spinner,stop)
05-08 12:07:17.250: D/CordovaActivity(1078): onMessage(spinner,stop)
05-08 12:07:17.260: W/PluginManager(1078): THREAD WARNING: exec() call to App.show blocked the main thread for 21ms. Plugin should use CordovaInterface.getThreadPool().
05-08 12:07:17.400: D/CordovaNetworkManager(1078): Connection Type: 3g
05-08 12:07:17.400: D/CordovaActivity(1078): onMessage(networkconnection,3g)
05-08 12:07:17.420: D/CordovaNetworkManager(1078): Connection Type: 3g
05-08 12:07:17.660: D/dalvikvm(1078): GC_FOR_ALLOC freed 458K, 14% free 3365K/3908K, paused 36ms, total 39ms
05-08 12:07:17.710: W/PluginManager(1078): THREAD WARNING: exec() call to Utils.writePref blocked the main thread for 95ms. Plugin should use CordovaInterface.getThreadPool().
05-08 12:07:17.780: W/PluginManager(1078): THREAD WARNING: exec() call to Utils.writePref blocked the main thread for 35ms. Plugin should use CordovaInterface.getThreadPool().
05-08 12:07:17.790: D/CordovaWebView(1078): >>> loadUrl(file:///data/data/com.AndroidShowNativePage/files/www/default/AndroidShowNativePage.html)
05-08 12:07:17.810: D/PluginManager(1078): init()
05-08 12:07:17.810: W/PluginManager(1078): THREAD WARNING: exec() call to Utils.loadSkin blocked the main thread for 29ms. Plugin should use CordovaInterface.getThreadPool().
05-08 12:07:17.820: D/CordovaWebView(1078): >>> loadUrlNow()
05-08 12:07:18.020: D/CordovaActivity(1078): onMessage(onPageStarted,file:///data/data/com.AndroidShowNativePage/files/www/default/AndroidShowNativePage.html)
05-08 12:07:23.320: D/CordovaActivity(1078): onMessage(spinner,stop)
05-08 12:07:23.370: D/CordovaNetworkManager(1078): Connection Type: 3g
05-08 12:07:23.400: D/CordovaNetworkManager(1078): Connection Type: 3g
05-08 12:07:23.400: D/CordovaActivity(1078): onMessage(networkconnection,3g)
05-08 12:07:24.010: D/CordovaWebViewClient(1078): onPageFinished(file:///data/data/com.AndroidShowNativePage/files/www/default/AndroidShowNativePage.html)
05-08 12:07:24.010: D/CordovaActivity(1078): onMessage(onPageFinished,file:///data/data/com.AndroidShowNativePage/files/www/default/AndroidShowNativePage.html)
05-08 12:07:24.240: I/Choreographer(1078): Skipped 32 frames! The application may be doing too much work on its main thread.
05-08 12:07:24.440: D/AndroidShowNativePage(1078): wlclient init started
05-08 12:07:24.530: D/AndroidShowNativePage(1078): Read cookies: null
05-08 12:07:24.560: D/AndroidShowNativePage(1078): CookieMgr read cookies: {}
05-08 12:07:24.870: W/AndroidShowNativePage(1078): Your application is using the WL.OptionsMenu API. Note that, if your application targets Android 3.0 (API level 11) or higher, WL.OptionsMenu might have no effect, depending on the device.
05-08 12:07:24.970: W/PluginManager(1078): THREAD WARNING: exec() call to DeviceAuth.getDeviceUUID blocked the main thread for 24ms. Plugin should use CordovaInterface.getThreadPool().
05-08 12:07:25.000: D/AndroidShowNativePage(1078): addDeviceIDHeader deviceIDSuccessCallback
05-08 12:07:25.050: W/PluginManager(1078): THREAD WARNING: exec() call to Utils.writePref blocked the main thread for 21ms. Plugin should use CordovaInterface.getThreadPool().
05-08 12:07:25.080: D/AndroidShowNativePage(1078): connectOnStartup finalizeInit
05-08 12:07:25.190: D/AndroidShowNativePage(1078): before: app init onSuccess
05-08 12:07:25.310: D/AndroidShowNativePage(1078): after: app init onSuccess
05-08 12:07:25.350: D/AndroidShowNativePage(1078): added onPause event handler
05-08 12:07:25.370: D/AndroidShowNativePage(1078): wlclient init success
05-08 12:26:11.550: D/CordovaActivity(1078): Paused the application!
05-08 12:26:11.550: D/CordovaWebView(1078): Handle the pause
05-08 12:26:11.650: W/PluginManager(1078): THREAD WARNING: exec() call to NativePage.show blocked the main thread for 151ms. Plugin should use CordovaInterface.getThreadPool().
05-08 12:26:12.620: I/Choreographer(1078): Skipped 60 frames! The application may be doing too much work on its main thread.
05-08 12:26:13.040: D/AndroidShowNativePage(1078): Flush called
05-08 12:26:17.070: I/Choreographer(1078): Skipped 75 frames! The application may be doing too much work on its main thread.

Do you get any errors either in Eclipse console or in the LogCat view? Provide the output from LogCat, that should help. Edit the question with this information.
The following permission needs to be added to AndroidManifest.xml as well:
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
Edit:
There is also the following tutorial to get signal strength: http://www.firstdroid.com/2010/05/12/get-provider-gsm-signal-strength/
I've followed it, and it worked for me in the Android emulator.
This is my Java implementation:
package com.testapp;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.LinearLayout;
import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.telephony.PhoneStateListener;
import android.telephony.SignalStrength;
import android.telephony.TelephonyManager;
import android.widget.Toast;
public class HelloNative extends Activity {
TelephonyManager tm;
MyPhoneStateListener MyListener;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
MyListener = new MyPhoneStateListener();
tm = (TelephonyManager)getSystemService(Context.TELEPHONY_SERVICE);
tm.listen(MyListener ,PhoneStateListener.LISTEN_SIGNAL_STRENGTHS);
LinearLayout linearLayout = new LinearLayout(this);
linearLayout.setOrientation(LinearLayout.VERTICAL);
setContentView(linearLayout);
Button submitButton = new Button(this);
submitButton.setText("Return to the Web App");
submitButton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
setResult(RESULT_OK);
finish();
};
});
linearLayout.addView(submitButton);
}
private class MyPhoneStateListener extends PhoneStateListener
{
/* Get the Signal strength from the provider, each time there is an update */
#Override
public void onSignalStrengthsChanged(SignalStrength signalStrength)
{
super.onSignalStrengthsChanged(signalStrength);
Toast.makeText(getApplicationContext(), "Signal strength is: "
+ String.valueOf(signalStrength.getGsmSignalStrength()), Toast.LENGTH_SHORT).show();
}
};
}

Android Custom Carrier Label nullpointerexception

I've added AOKP's Custom Carrier Label options to my rom and everything works with the exception of getting a Settings fc when OK is clicked in the dialog window...The customlabeltextsummary is updated correctly and the carrier is changed as it should be...
Settings.java :
package com.android.settings.cyanogenmod;
import android.app.AlertDialog;
import android.content.ContentResolver;
import android.content.Context;
import android.content.pm.PackageManager.NameNotFoundException;
import android.os.Bundle;
import android.content.ContentResolver;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.RemoteException;
import android.os.ServiceManager;
import android.view.IWindowManager;
import android.preference.CheckBoxPreference;
import android.preference.Preference;
import android.preference.PreferenceScreen;
import android.provider.Settings;
import android.preference.CheckBoxPreference;
import android.preference.ListPreference;
import android.preference.Preference;
import android.preference.PreferenceActivity;
import android.preference.PreferenceGroup;
import android.preference.PreferenceScreen;
import android.preference.Preference.OnPreferenceChangeListener;
import android.provider.Settings;
import android.text.Spannable;
import android.util.Log;
import android.view.IWindowManager;
import android.view.Display;
import android.view.LayoutInflater;
import android.widget.EditText;
import com.android.settings.R;
import com.android.settings.SettingsPreferenceFragment;
import com.android.settings.Utils;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class SystemSettings extends SettingsPreferenceFragment implements
Preference.OnPreferenceChangeListener{
private static final String TAG = "SystemSettings";
private static final String KEY_POWER_BUTTON_TORCH = "power_button_torch";
private CheckBoxPreference mPowerButtonTorch;
private static final String KEY_CHRONUS = "chronus";
private static final String PREF_FORCE_DUAL_PANEL = "force_dualpanel";
private static final String PREF_CUSTOM_CARRIER_LABEL = "custom_carrier_label";
Preference mCustomLabel;
Context mContext;
String mCustomLabelText = null;
CheckBoxPreference mDualpane;
private boolean torchSupported() {
return getResources().getBoolean(R.bool.has_led_flash);
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Load the preferences from an XML resource
addPreferencesFromResource(R.xml.system_settings);
mCustomLabel = findPreference(PREF_CUSTOM_CARRIER_LABEL);
updateCustomLabelTextSummary();
// Dont display the lock clock preference if its not installed
removePreferenceIfPackageNotInstalled(findPreference(KEY_CHRONUS));
mPowerButtonTorch = (CheckBoxPreference) findPreference(KEY_POWER_BUTTON_TORCH);
if (torchSupported()) {
mPowerButtonTorch.setChecked((Settings.System.getInt(getActivity().
getApplicationContext().getContentResolver(),
Settings.System.POWER_BUTTON_TORCH, 0) == 1));
} else {
getPreferenceScreen().removePreference(mPowerButtonTorch);
}
mDualpane = (CheckBoxPreference) findPreference(PREF_FORCE_DUAL_PANEL);
mDualpane.setOnPreferenceChangeListener(this);
}
#Override
public void onResume() {
super.onResume();
}
#Override
public void onPause() {
super.onPause();
}
#Override
public boolean onPreferenceTreeClick(PreferenceScreen preferenceScreen, Preference preference) {
if (preference == mPowerButtonTorch) {
boolean enabled = mPowerButtonTorch.isChecked();
Settings.System.putInt(getContentResolver(), Settings.System.POWER_BUTTON_TORCH,
enabled ? 1 : 0);
return true;
} else if (preference == mCustomLabel) {
AlertDialog.Builder alert = new AlertDialog.Builder(getActivity());
alert.setTitle(R.string.custom_carrier_label_title);
alert.setMessage(R.string.custom_carrier_label_explain);
// Set an EditText view to get user input
final EditText input = new EditText(getActivity());
input.setText(mCustomLabelText != null ? mCustomLabelText : "");
alert.setView(input);
alert.setPositiveButton(getResources().getString(R.string.ok), new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
String value = ((Spannable) input.getText()).toString();
Settings.System.putString(getActivity().getContentResolver(),
Settings.System.CUSTOM_CARRIER_LABEL, value);
updateCustomLabelTextSummary();
Intent i = new Intent();
i.setAction("com.android.settings.LABEL_CHANGED");
mContext.sendBroadcast(i);
}
});
alert.setNegativeButton(getResources().getString(R.string.cancel), new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
// Canceled.
}
});
alert.show();
}
return super.onPreferenceTreeClick(preferenceScreen, preference);
}
public boolean onPreferenceChange(Preference preference, Object objValue) {
ContentResolver cr = getActivity().getContentResolver();
if (preference == mDualpane) {
Settings.System.putInt(getActivity().getContentResolver(),
Settings.System.FORCE_DUAL_PANEL,
((CheckBoxPreference)preference).isChecked() ? 0 : 1);
return true;
}
return false;
}
private boolean removePreferenceIfPackageNotInstalled(Preference preference) {
String intentUri=((PreferenceScreen) preference).getIntent().toUri(1);
Pattern pattern = Pattern.compile("component=([^/]+)/");
Matcher matcher = pattern.matcher(intentUri);
String packageName=matcher.find()?matcher.group(1):null;
if(packageName != null) {
try {
getPackageManager().getPackageInfo(packageName, 0);
} catch (NameNotFoundException e) {
Log.e(TAG,"package "+packageName+" not installed, hiding preference.");
getPreferenceScreen().removePreference(preference);
return true;
}
}
return false;
}
private void updateCustomLabelTextSummary() {
mCustomLabelText = Settings.System.getString(getActivity().getContentResolver(),
Settings.System.CUSTOM_CARRIER_LABEL);
if (mCustomLabelText == null || mCustomLabelText.length() == 0) {
mCustomLabel.setSummary(R.string.custom_carrier_label_notset);
} else {
mCustomLabel.setSummary(mCustomLabelText);
}
}
}
logcat :
W/System.err(13551): Removed 2131231241
W/System.err(13551): Removed 2131231255
D/dalvikvm( 3528): GC_CONCURRENT freed 384K, 16% free 2993K/3552K, paused 2ms+4ms, total 33ms
D/dalvikvm(13551): GC_CONCURRENT freed 190K, 10% free 3282K/3644K, paused 2ms+8ms, total 37ms
D/AndroidRuntime(13551): Shutting down VM
W/dalvikvm(13551): threadid=1: thread exiting with uncaught exception (group=0x40d12600)
E/AndroidRuntime(13551): FATAL EXCEPTION: main
E/AndroidRuntime(13551): java.lang.NullPointerException
E/AndroidRuntime(13551): at com.android.settings.cyanogenmod.SystemSettings$1.onClick(SystemSettings.java:143)
E/AndroidRuntime(13551): at com.android.internal.app.AlertController$ButtonHandler.handleMessage(AlertController.java:166)
E/AndroidRuntime(13551): at android.os.Handler.dispatchMessage(Handler.java:99)
E/AndroidRuntime(13551): at android.os.Looper.loop(Looper.java:137)
E/AndroidRuntime(13551): at android.app.ActivityThread.main(ActivityThread.java:5191)
E/AndroidRuntime(13551): at java.lang.reflect.Method.invokeNative(Native Method)
E/AndroidRuntime(13551): at java.lang.reflect.Method.invoke(Method.java:511)
E/AndroidRuntime(13551): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:795)
E/AndroidRuntime(13551): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:562)
E/AndroidRuntime(13551): at dalvik.system.NativeStart.main(Native Method)
W/ActivityManager( 1108): Force finishing activity com.android.settings/.SubSettings
W/ActivityManager( 1108): Activity pause timeout for ActivityRecord{40ff74b8 u0 com.android.settings/.SubSettings}
D/dalvikvm(13124): GC_FOR_ALLOC freed 411K, 22% free 3616K/4608K, paused 28ms, total 34ms
I/Process (13551): Sending signal. PID: 13551 SIG: 9
W/InputDispatcher( 1108): channel '41188140 com.android.settings/com.android.settings.SubSettings (server)' ~ Consumer closed input channel or an error occurred. events=0x9
I/WindowState( 1108): WIN DEATH: Window{41369d90 u0 com.android.settings/com.android.settings.SubSettings}
I/ActivityManager( 1108): Process com.android.settings (pid 13551) has died.
E/InputDispatcher( 1108): channel '41188140 com.android.settings/com.android.settings.SubSettings (server)' ~ Channel is unrecoverably broken and will be disposed!
W/InputDispatcher( 1108): channel '40ffd998 com.android.settings/com.android.settings.Settings (server)' ~ Consumer closed input channel or an error occurred. events=0x9
E/InputDispatcher( 1108): channel '40ffd998 com.android.settings/com.android.settings.Settings (server)' ~ Channel is unrecoverably broken and will be disposed!
W/InputDispatcher( 1108): Attempted to unregister already unregistered input channel '41188140 com.android.settings/com.android.settings.SubSettings (server)'
W/InputDispatcher( 1108): Attempted to unregister already unregistered input channel '40ffd998 com.android.settings/com.android.settings.Settings (server)'
I/WindowState( 1108): WIN DEATH: Window{41188140 u0 com.android.settings/com.android.settings.SubSettings}
I/WindowState( 1108): WIN DEATH: Window{40ffd998 u0 com.android.settings/com.android.settings.Settings}
I/ActivityManager( 1108): Start proc com.android.settings for activity com.android.settings/.Settings: pid=13575 uid=1000 gids={41000, 1015, 1028, 3002, 3001, 3003, 3007}
W/WindowManager( 1108): Rebuild removed 7 windows but added 6
W/WindowManager( 1108): This window was lost: Window{41369d90 u0 com.android.settings/com.android.settings.SubSettings EXITING}
W/WindowManager( 1108): mDisplayId=0 mSession=Session{41e7d3b0 13551:1000} mClient=android.os.BinderProxy#4108dde8
line 143 is as follows :
mContext.sendBroadcast(i);
anyone got an idea whats going on here?

mContext is null, since it is declared at the top of your class, but never given anything to hold.
You could probably use getActivity() in place of mContext since this is a Fragment and Activity is a Context subclass.
This means
mContext.sendBroadcast(i);
should be
getActivity().sendBroadcast(i);