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Azure Notification Hubs for Android: How do I handle Data-Messages with a Background-Service?

I'm trying to make an app that is able to handle (data-)messages sent by the Azure Notification Hubs. At the current state it sends a Notification when recieving a payload by Azure. While the app is running in the foreground (or still open in the Quick Panel) it has no problems at all and onPushNotificationReceived() handles the incoming message just fine, but when removing the app from the Quick Panel I get an error for trying to invoke a null object refrence:
Logcat
2021-07-22 15:27:33.675 23017-23053/com.example.fcmtutorial1app E/AndroidRuntime: FATAL EXCEPTION: Firebase-Messaging-Intent-Handle
Process: com.example.fcmtutorial1app, PID: 23017
java.lang.NullPointerException: Attempt to invoke interface method 'void com.microsoft.windowsazure.messaging.notificationhubs.NotificationListener.onPushNotificationReceived(android.content.Context, com.google.firebase.messaging.RemoteMessage)' on a null object reference
at com.microsoft.windowsazure.messaging.notificationhubs.FirebaseReceiver.onMessageReceived(FirebaseReceiver.java:52)
at com.google.firebase.messaging.FirebaseMessagingService.dispatchMessage(com.google.firebase:firebase-messaging##22.0.0:13)
at com.google.firebase.messaging.FirebaseMessagingService.passMessageIntentToSdk(com.google.firebase:firebase-messaging##22.0.0:8)
at com.google.firebase.messaging.FirebaseMessagingService.handleMessageIntent(com.google.firebase:firebase-messaging##22.0.0:3)
at com.google.firebase.messaging.FirebaseMessagingService.handleIntent(com.google.firebase:firebase-messaging##22.0.0:3)
at com.google.firebase.messaging.EnhancedIntentService.lambda$processIntent$0$EnhancedIntentService(com.google.firebase:firebase-messaging##22.0.0:1)
at com.google.firebase.messaging.EnhancedIntentService$$Lambda$0.run(Unknown Source:6)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
at com.google.android.gms.common.util.concurrent.zza.run(Unknown Source:6)
at java.lang.Thread.run(Thread.java:923)
This only happens when sending data messages, since the Firebase Service handles Messages with notification payload without invoking onPushNotificationReceived().
I've tried the following to fix this:
Extending CustomNotificationListener.class with android.app.Service
Replacing onPushNotificationReceived() with Thunderbirds onMessageReceived()
The first solution resulted in the same error and the second one resulted in no messages at all.
If someone has a way to fix this or knows what could be the fault, I'd be really be happy if you could write an answer :)
Here is the code for both classes (android.app.Service is still included although it didn't work for me). Thanks in advance!
MainActivity.class
package com.example.fcmtutorial1app;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.NotificationCompat;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.content.Context;
import android.os.Build;
import android.os.Bundle;
import android.util.Log;
import com.microsoft.windowsazure.messaging.notificationhubs.NotificationHub;
public class MainActivity extends AppCompatActivity
{
public static final String CHANNEL_1_ID = "Channel1";
public static final String CHANNEL_2_ID = "Channel2";
public static String editTextTitle;
public static String editTextMessage;
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
createNotificationsChannels();
NotificationHub.setListener(new CustomNotificationListener());
NotificationHub.start(this.getApplication(), "spfcmtutorial1nhub", "Endpoint=sb://azurecloudmessaging.servicebus.windows.net/;SharedAccessKeyName=DefaultListenSharedAccessSignature;SharedAccessKey=abc[...]xyz");
}
public static void sendCloudMessage(Context context)
{
editTextTitle = CustomNotificationListener.title;
editTextMessage = CustomNotificationListener.body;
NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(context, CHANNEL_1_ID)
.setSmallIcon(R.drawable.ic_launcher)
.setContentTitle(editTextTitle)
.setContentText(editTextMessage)
.setPriority(NotificationCompat.PRIORITY_HIGH)
.setCategory(NotificationCompat.CATEGORY_MESSAGE);
NotificationManager notificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
notificationManager.notify(1, notificationBuilder.build());
Log.v("MSG", "SENDCLOUDMESSAGE WAS ACTIVATED");
}
public void createNotificationsChannels() //Channel 2 is for tests only
{
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)
{
NotificationChannel channel1 = new NotificationChannel(
CHANNEL_1_ID,
"Channel 1",
NotificationManager.IMPORTANCE_HIGH
);
channel1.setDescription("This is Channel 1");
NotificationChannel channel2 = new NotificationChannel(
CHANNEL_2_ID,
"Channel 2",
NotificationManager.IMPORTANCE_LOW
);
channel2.setDescription("This is Channel 2");
NotificationManager manager = getSystemService(NotificationManager.class);
manager.createNotificationChannel(channel1);
manager.createNotificationChannel(channel2);
}
}
}
CustomNotificationListener.class
package com.example.fcmtutorial1app;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.os.IBinder;
import android.util.Log;
import androidx.annotation.Nullable;
import com.google.firebase.messaging.RemoteMessage;
import com.microsoft.windowsazure.messaging.notificationhubs.NotificationListener;
import java.util.Map;
public class CustomNotificationListener extends Service implements NotificationListener
{
private static final String TAG = "Message";
public static String title;
public static String body;
public static String dataTitle;
public static String dataBody;
#Override
public int onStartCommand(Intent intent, int flags, int startId)
{
Log.d(TAG, "Service started");
return Service.START_NOT_STICKY;
}
#Override
public void onPushNotificationReceived(Context context, RemoteMessage message) //FATAL EXEPTION: Firebase-Messaging-Intent-Handle HERE
{
RemoteMessage.Notification notification = message.getNotification();
try { title = notification.getTitle(); } catch(Exception e) {}
try { body = notification.getBody(); } catch (Exception e) {}
Map<String, String> data = message.getData();
//region LOGGING
if (message != null)
{
Log.d(TAG, "Message Notification Title: " + title);
Log.d(TAG, "Message Notification Body: " + body);
}
else { Log.e(TAG, "ERROR, no message found"); }
if (data != null)
{
for (Map.Entry<String, String> entry : data.entrySet())
{
Log.d(TAG, "key, " + entry.getKey() + "value " + entry.getValue());
}
}
else { Log.e(TAG, "ERROR, no data found"); }
//endregion
Log.v("VERBOSE", data.get("property1"));
MainActivity.sendCloudMessage(context);
}
#Nullable
#Override
public IBinder onBind(Intent intent) {
return null;
}
}
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.fcmtutorial1app">
<application
android:allowBackup="true"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="#style/Theme.FCMTutorial1App">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<service android:name=".CustomNotificationListener"></service>
</application>
</manifest>

To answer this question, we'll need to discuss some Android lifecycle concepts as documented at https://developer.android.com:
Process and Application Lifecycle
Activity Lifecycle
In the code you provide above, you call NotificationHub.setListener in your application's primary entrypoint, MainActivity. As you see, this works when your end user has started the application manually because MainActivity.onCreate gets invoked.
However, there's a second entrypoint in your scenario: FirebaseMessagingService starting the application when a data-only notification is received in the background. This is subtle and easy to miss - because if the payload contains a notification component, Android will still route to MainActivity when the notification is clicked in the system tray.
In this case MainActivity isn't involved, so MainActivity.onCreate and NotificationHub.setListener are never called as the application initialized, and the following line from the stack trace encounters a null reference:
mHub.getInstanceListener().onPushNotificationReceived(this.getApplicationContext(), remoteMessage);
To fix this, you'll need to call NotificationHub.setListener somewhere that gets called anytime the application gets initialized, regardless of the entrypoint.
The most natural choice is to setup the NotificationHub at the Application level by extending android.app.Application, overriding the onCreate() method, and updating your manifest.

avoid of send null from destroyed activity to restarted service

I want to programing app for data track in background , so I use service .
I want to write a program that monitors all data sent and received by the device, and when the total volume of received or received messages reaches a specified value, the Internet device is turned off.
So I used the following code to monitor the data:
 
mStartRX = TrafficStats.getTotalRxBytes ();
mStartTX = TrafficStats.getTotalTxBytes ();
And I used the services to work on the background in the background.
To specify the download or upload limit from the user with edittext, I requested this limit in mainactivity and send this value to the service.
The problem is when: When I destroy the program, I will restart the service and get the NULL value and the program crashes.
My application code:
Main Activity :
package ir.alexandre9009.service;
import android.app.AlertDialog;
import android.content.Context;
import android.net.TrafficStats;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.os.Handler;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class MainActivity extends Activity {
public static Handler mHandler = new Handler();
public static long UPP;
public static long DLL;
Button startService,stopService;
public Context context=this;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (FirstService.mStartRX == TrafficStats.UNSUPPORTED || FirstService.mStartTX == TrafficStats.UNSUPPORTED) {
AlertDialog.Builder alert = new AlertDialog.Builder(this);
alert.setTitle("Uh Oh!");
alert.setMessage("Your device does not support traffic stat monitoring.");
alert.show();
} else {
mHandler.postDelayed(mRunnable, 1000);
}
startService=(Button)findViewById(R.id.startService);
stopService=(Button)findViewById(R.id.stopService);
startService.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
EditText UP = (EditText) findViewById(R.id.UP);
String UPPP = UP.getText().toString();
UPP=Long.parseLong(UPPP);
EditText DL = (EditText) findViewById(R.id.DL);
String DLLL = DL.getText().toString();
DLL=Long.parseLong(DLLL);
Intent intent = new Intent(getApplicationContext(), FirstService.class);
String myString = DLLL;
intent.putExtra("StringName", myString);
startService(intent);
}
});
stopService.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
stopService(new Intent(getBaseContext(),FirstService.class));
}
});
}
public final Runnable mRunnable = new Runnable() {
public void run() {
TextView RX = (TextView)findViewById(R.id.RX);
TextView TX = (TextView)findViewById(R.id.TX);
RX.setText(Long.toString(FirstService.rxBytes));
TX.setText(Long.toString(FirstService.txBytes));
mHandler.postDelayed(mRunnable, 1000);
}
};
}
Service :
package ir.alexandre9009.service;
import android.app.AlertDialog;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.net.TrafficStats;
import android.net.wifi.WifiManager;
import android.os.Handler;
import android.os.IBinder;
import android.widget.TextView;
import android.widget.Toast;
public class FirstService extends Service{
public static long mStartRX ;
public static long mStartTX ;
public static long rxBytes ;
public static long txBytes ;
public long dl=MainActivity.DLL;
Context context=this;
private final Runnable mRunnable = new Runnable() {
public void run() {
rxBytes = (TrafficStats.getTotalRxBytes()- mStartRX)/1048576;
txBytes = (TrafficStats.getTotalTxBytes()- mStartTX)/1048576;
if (rxBytes==2) {
stopService(new Intent(getBaseContext(),FirstService.class));
Intent i = new Intent(context,MainActivity.class);
context.startActivity(i);
// WifiManager wifiManager = (WifiManager)getApplicationContext().getSystemService(Context.WIFI_SERVICE);
// wifiManager.setWifiEnabled(false);
//معرفی توست برای نمایش یک پیام کوتاه به کاربر در هنگام خاموش کردن وای فای
Toast.makeText(FirstService.this, "هشدار", Toast.LENGTH_LONG).show();
}
mHandler.postDelayed(mRunnable, 1000);
}
};
private Handler mHandler = new Handler();
#Override
public IBinder onBind(Intent arg0) {
return null;
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
Toast.makeText(this,"staart",Toast.LENGTH_LONG).show();
mStartTX=0;
mStartRX=0;
mStartRX = TrafficStats.getTotalRxBytes();
mStartTX = TrafficStats.getTotalTxBytes();
mHandler.postDelayed(mRunnable, 1000);
return Service.START_STICKY;
}
#Override
public void onDestroy() {
TrafficStats.clearThreadStatsTag();
Toast.makeText(this,"FirstService Stoped",Toast.LENGTH_LONG).show();
mStartTX=0;
mStartRX=0;
super.onDestroy();
}
}
AndroidManifest :
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="ir.alexandre9009.service">
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE"/>
<uses-permission android:name="android.permission.UPDATE_DEVICE_STATS" />
<uses-permission android:name="android.permission.WAKE_LOCK" />
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<service android:name=".FirstService"
>
</service>
</application>
</manifest>
please help me ...

The problem is with this line
public long dl=MainActivity.DLL;
You're referring to a variable in the Activity, surly when the Activity is destroyed, this variable is no longer in scope, thus you get Null Exception.
You must get this value using the intent.
The other problem is that you can't prevent any service from being killed by the system except foreground services which need to show a notification to the user. But this is not suitable for your situation.
Therefore, the best approach for you is to check whether intent is null or not. If it is not null, you get the value and save it into Preferences or Database or somewhere, if it is null, you retrieve the value from where you stored it before.

Java Android upload image to sever

I have a probleme with sending a photo to server. When I want to upload a photo a see in console:
java.lang.NullPointerException: Attempt to invoke virtual method 'boolean android.graphics.Bitmap.compress(android.graphics.Bitmap$CompressFormat, int, java.io.OutputStream)' on a null object reference
I did this :
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.provider.MediaStore;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;
import org.apache.commons.codec.binary.Base64;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;
import java.io.ByteArrayOutputStream;
import java.util.ArrayList;
public class MainActivity extends Activity {
Button btpic, btnup;
private Uri fileUri;
String picturePath;
Uri selectedImage;
Bitmap photo;
String ba1;
public static String URL = "Paste your URL here";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btpic = (Button) findViewById(R.id.cpic);
btpic.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
clickpic();
}
});
btnup = (Button) findViewById(R.id.up);
btnup.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
upload();
}
});
}
private void upload() {
// Image location URL
Log.e("path", "----------------" + picturePath);
// Image
Bitmap bm = BitmapFactory.decodeFile(picturePath);
ByteArrayOutputStream bao = new ByteArrayOutputStream();
bm.compress(Bitmap.CompressFormat.JPEG, 90, bao);
byte[] ba = bao.toByteArray();
ba1 = Base64.encodeBase64String(ba);
// Log.e("base64", "-----" + ba1);
// Upload image to server
new uploadToServer().execute();
}
private void clickpic() {
// Check Camera
if (getApplicationContext().getPackageManager().hasSystemFeature(
PackageManager.FEATURE_CAMERA)) {
// Open default camera
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri);
// start the image capture Intent
startActivityForResult(intent, 100);
} else {
Toast.makeText(getApplication(), "Camera not supported", Toast.LENGTH_LONG).show();
}
}
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == 100 && resultCode == RESULT_OK) {
selectedImage = data.getData();
photo = (Bitmap) data.getExtras().get("data");
// Cursor to get image uri to display
String[] filePathColumn = {MediaStore.Images.Media.DATA};
Cursor cursor = getContentResolver().query(selectedImage,
filePathColumn, null, null, null);
cursor.moveToFirst();
int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
picturePath = cursor.getString(columnIndex);
cursor.close();
Bitmap photo = (Bitmap) data.getExtras().get("data");
ImageView imageView = (ImageView) findViewById(R.id.Imageprev);
imageView.setImageBitmap(photo);
}
}
public class uploadToServer extends AsyncTask<Void, Void, String> {
private ProgressDialog pd = new ProgressDialog(MainActivity.this);
protected void onPreExecute() {
super.onPreExecute();
pd.setMessage("Wait image uploading!");
pd.show();
}
#Override
protected String doInBackground(Void... params) {
ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
nameValuePairs.add(new BasicNameValuePair("base64", ba1));
nameValuePairs.add(new BasicNameValuePair("ImageName", System.currentTimeMillis() + ".jpg"));
try {
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(URL);
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = httpclient.execute(httppost);
String st = EntityUtils.toString(response.getEntity());
Log.v("log_tag", "In the try Loop" + st);
} catch (Exception e) {
Log.v("log_tag", "Error in http connection " + e.toString());
}
return "Success";
}
protected void onPostExecute(String result) {
super.onPostExecute(result);
pd.hide();
pd.dismiss();
}
}
}
A log :
08:52:35.199 941-941/com.example.krzysiek.myapplication76 E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.krzysiek.myapplication76, PID: 941
java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.net.Uri.toString()' on a null object reference
at com.example.krzysiek.myapplication76.MainActivity.clickpic(MainActivity.java:90)
at com.example.krzysiek.myapplication76.MainActivity.access$000(MainActivity.java:34)
at com.example.krzysiek.myapplication76.MainActivity$1.onClick(MainActivity.java:52)
at android.view.View.performClick(View.java:5697)
at android.widget.TextView.performClick(TextView.java:10826)
at android.view.View$PerformClick.run(View.java:22526)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:158)
at android.app.ActivityThread.main(ActivityThread.java:7224)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)
11-15 08:52:56.003 941-1089/com.example.krzysiek.myapplication76 W/System: ClassLoader referenced unknown path: /data/data/com.example.krzysiek.myapplication76/lib
11-15 08:54:47.258 941-950/com.example.krzysiek.myapplication76 W/art: Suspending all threads took: 12.657ms
My manifest :
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.krzysiek.myapplication76">
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />
<uses-feature android:name="android.hardware.camera" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.INTERNET"/>
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity
android:name=".MainActivity"
android:label="#string/app_name"
android:theme="#style/AppTheme.NoActionBar">
<intent-filter>
<action android:name="android.intent.action.MAIN"/>
<category android:name="android.intent.category.LAUNCHER"/>
</intent-filter>
</activity>
</application>
</manifest>

Bitmap bm = BitmapFactory.decodeFile(picturePath); returns null bitmap.
The reason would be need read external storage permission. Make sure you have supporting runtime permissions if you are using Android Operating System version which is above 5.0
Also make sure your picturePath represents a file which has URI scheme image.
Good luck there.
Emre

Facebook friend picker SDK sample not working Android

Please help me to get the facebook friends from my profile using 3.14 SDK. There is no error in the code but the problem is getting empty list while fetching friends in my profile. I am getting the error in logcat saying .
05-08 16:18:49.252: E/ActivityThread(25644): Failed to find provider info for com.facebook.orca.provider.PlatformProvider<br>
05-08 16:42:20.453: I/QCNEA(28696): |NIMS| getaddrinfo: hostname graph.facebook.com servname NULL numeric 4 appname <br>
05-08 16:51:32.482: D/Request(31861): Warning: Sessionless Request needs token but missing either application ID or client token<br>
Also i am producing the complete code for your reference below
FriendPickerApplication.java*
package com.facebook.samples.friendpicker;
import android.app.Application;
import com.facebook.model.GraphUser;
import java.util.List;
// We use a custom Application class to store our minimal state data (which users have been selected).
// A real-world application will likely require a more robust data model.
public class FriendPickerApplication extends Application {
private List<GraphUser> selectedUsers;
public List<GraphUser> getSelectedUsers() {
return selectedUsers;
}
public void setSelectedUsers(List<GraphUser> selectedUsers) {
this.selectedUsers = selectedUsers;
}
}<br>
FriendPickerSampleActivity.java
package com.facebook.samples.friendpicker;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import com.facebook.AppEventsLogger;
import com.facebook.Session.NewPermissionsRequest;
import com.facebook.SessionState;
import com.facebook.UiLifecycleHelper;
import com.facebook.model.GraphUser;
import com.facebook.Session;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
public class FriendPickerSampleActivity extends FragmentActivity {
private static final List<String> PERMISSIONS = new ArrayList<String>() {
{
add("user_friends");
add("public_profile");
}
};
private static final int PICK_FRIENDS_ACTIVITY = 1;
private Button pickFriendsButton;
private TextView resultsTextView;
private UiLifecycleHelper lifecycleHelper;
boolean pickFriendsWhenSessionOpened;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
resultsTextView = (TextView) findViewById(R.id.resultsTextView);
pickFriendsButton = (Button) findViewById(R.id.pickFriendsButton);
pickFriendsButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
onClickPickFriends();
}
});
lifecycleHelper = new UiLifecycleHelper(this, new Session.StatusCallback() {
#Override
public void call(Session session, SessionState state, Exception exception) {
onSessionStateChanged(session, state, exception);
}
});
lifecycleHelper.onCreate(savedInstanceState);
ensureOpenSession();
}
#Override
protected void onStart() {
super.onStart();
// Update the display every time we are started.
displaySelectedFriends(RESULT_OK);
}
#Override
protected void onResume() {
super.onResume();
// Call the 'activateApp' method to log an app event for use in analytics and advertising reporting. Do so in
// the onResume methods of the primary Activities that an app may be launched into.
AppEventsLogger.activateApp(this);
}
public void onActivityResult(int requestCode, int resultCode, Intent data) {
switch (requestCode) {
case PICK_FRIENDS_ACTIVITY:
displaySelectedFriends(resultCode);
break;
default:
Session.getActiveSession().onActivityResult(this, requestCode, resultCode, data);
break;
}
}
private boolean ensureOpenSession() {
if (Session.getActiveSession() == null ||
!Session.getActiveSession().isOpened()) {
Session.openActiveSession(
this,
true,
PERMISSIONS,
new Session.StatusCallback() {
#Override
public void call(Session session, SessionState state, Exception exception) {
onSessionStateChanged(session, state, exception);
}
});
return false;
}
return true;
}
private boolean sessionHasNecessaryPerms(Session session) {
if (session != null && session.getPermissions() != null) {
for (String requestedPerm : PERMISSIONS) {
if (!session.getPermissions().contains(requestedPerm)) {
return false;
}
}
return true;
}
return false;
}
private List<String> getMissingPermissions(Session session) {
List<String> missingPerms = new ArrayList<String>(PERMISSIONS);
if (session != null && session.getPermissions() != null) {
for (String requestedPerm : PERMISSIONS) {
if (session.getPermissions().contains(requestedPerm)) {
missingPerms.remove(requestedPerm);
}
}
}
return missingPerms;
}
private void onSessionStateChanged(final Session session, SessionState state, Exception exception) {
if (state.isOpened() && !sessionHasNecessaryPerms(session)) {
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setMessage(R.string.need_perms_alert_text);
builder.setPositiveButton(
R.string.need_perms_alert_button_ok,
new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
session.requestNewReadPermissions(
new NewPermissionsRequest(
FriendPickerSampleActivity.this,
getMissingPermissions(session)));
}
});
builder.setNegativeButton(
R.string.need_perms_alert_button_quit,
new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
finish();
}
});
builder.show();
} else if (pickFriendsWhenSessionOpened && state.isOpened()) {
pickFriendsWhenSessionOpened = false;
startPickFriendsActivity();
}
}
private void displaySelectedFriends(int resultCode) {
String results = "";
FriendPickerApplication application = (FriendPickerApplication) getApplication();
Collection<GraphUser> selection = application.getSelectedUsers();
if (selection != null && selection.size() > 0) {
ArrayList<String> names = new ArrayList<String>();
for (GraphUser user : selection) {
names.add(user.getName());
}
results = TextUtils.join(", ", names);
} else {
results = "<No friends selected>";
}
resultsTextView.setText(results);
}
private void onClickPickFriends() {
startPickFriendsActivity();
}
private void startPickFriendsActivity() {
if (ensureOpenSession()) {
Intent intent = new Intent(this, PickFriendsActivity.class);
// Note: The following line is optional, as multi-select behavior is the default for
// FriendPickerFragment. It is here to demonstrate how parameters could be passed to the
// friend picker if single-select functionality was desired, or if a different user ID was
// desired (for instance, to see friends of a friend).
PickFriendsActivity.populateParameters(intent, null, true, true);
startActivityForResult(intent, PICK_FRIENDS_ACTIVITY);
} else {
pickFriendsWhenSessionOpened = true;
}
}
} <br>
PickFriendsActivity.java
package com.facebook.samples.friendpicker;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.widget.Toast;
import com.facebook.FacebookException;
import com.facebook.model.GraphUser;
import com.facebook.widget.FriendPickerFragment;
import com.facebook.widget.PickerFragment;
import java.util.List;
public class PickFriendsActivity extends FragmentActivity {
FriendPickerFragment friendPickerFragment;
public static void populateParameters(Intent intent, String userId,
boolean multiSelect, boolean showTitleBar) {
intent.putExtra(FriendPickerFragment.USER_ID_BUNDLE_KEY, userId);
intent.putExtra(FriendPickerFragment.MULTI_SELECT_BUNDLE_KEY,
multiSelect);
intent.putExtra(FriendPickerFragment.SHOW_TITLE_BAR_BUNDLE_KEY,
showTitleBar);
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.pick_friends_activity);
FragmentManager fm = getSupportFragmentManager();
if (savedInstanceState == null) {
// First time through, we create our fragment programmatically.
final Bundle args = getIntent().getExtras();
friendPickerFragment = new FriendPickerFragment(args);
fm.beginTransaction()
.add(R.id.friend_picker_fragment, friendPickerFragment)
.commit();
} else {
// Subsequent times, our fragment is recreated by the framework and
// already has saved and
// restored its state, so we don't need to specify args again. (In
// fact, this might be
// incorrect if the fragment was modified programmatically since it
// was created.)
friendPickerFragment = (FriendPickerFragment) fm
.findFragmentById(R.id.friend_picker_fragment);
}
friendPickerFragment
.setOnErrorListener(new PickerFragment.OnErrorListener() {
#Override
public void onError(PickerFragment<?> fragment,
FacebookException error) {
PickFriendsActivity.this.onError(error);
}
});
friendPickerFragment
.setOnDoneButtonClickedListener(new PickerFragment.OnDoneButtonClickedListener() {
#Override
public void onDoneButtonClicked(PickerFragment<?> fragment) {
// We just store our selection in the Application for
// other activities to look at.
FriendPickerApplication application = (FriendPickerApplication) getApplication();
application.setSelectedUsers(friendPickerFragment
.getSelection());
setResult(RESULT_OK, null);
finish();
}
});
}
private void onError(Exception error) {
String text = getString(R.string.exception, error.getMessage());
Toast toast = Toast.makeText(this, text, Toast.LENGTH_SHORT);
toast.show();
}
#Override
protected void onStart() {
super.onStart();
try {
FriendPickerApplication application = (FriendPickerApplication) getApplication();
List<GraphUser> selectedUsers = application.getSelectedUsers();
if (selectedUsers != null && !selectedUsers.isEmpty()) {
friendPickerFragment.setSelection(selectedUsers);
}
// Load data, unless a query has already taken place.
friendPickerFragment.loadData(false);
} catch (Exception ex) {
onError(ex);
}
}
}<br>
Androidmanifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.facebook.samples.friendpicker"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk android:minSdkVersion="8" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<application
android:name=".FriendPickerApplication"
android:icon="#drawable/icon"
android:label="#string/app_name"
android:theme="#android:style/Theme.NoTitleBar" >
<activity
android:name="FriendPickerSampleActivity"
android:label="#string/app_name"
android:windowSoftInputMode="adjustResize" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="PickFriendsActivity"
android:label="Pick Friends" >
</activity>
<activity
android:name="com.facebook.LoginActivity"
android:label="#string/app_name"
android:theme="#android:style/Theme.Translucent.NoTitleBar" />
<meta-data
android:name="com.facebook.sdk.ApplicationId"
android:value="#string/app_id" />
<provider
android:name="com.facebook.NativeAppCallContentProvider"
android:authorities="com.facebook.app.NativeAppCallContentProvider1441068969495032"
android:exported="true" />
</application>
</manifest>

After a long struggle I found my own solution to the above question. Facebook have released their new SDK recently to enhance the level of security. There are a few requirements to use facebook SDK in your app.
The app should be sent for submission and needs to be approved by facebook to be use inside facebook, to enable your own app to show friends details, access locations and other special permissions The approval formalities are similar to the ones for app store in Google Play.
The application must be listed in Google Play, or you may be able to integrate it as a test user (i.e like beta testing in Google Play).
The application should have a proper package name, launching activity, domain name, website url and email.
The app id registered must match with an app name and hash key that must be generated for a user developing on different machines
The basic application information, including screenshots, description, and app logo needs to be added
Once after the successful approval, an "active" symbol will be displayed near your app name.
I hope this will be useful for others!!!
More information on Facebook site.

After spending a good number of hours trying to resolve this, I would like to add the following for anyone still looking:
The only friends you will see in the list with user_friend permissions is other users that have logged in and approved your app. I.e. if no-one else is using it, you will se noone in the list (I know, if you read it all, this is obvious)
The easiest way of testing this is to set up a test app, add test users in the dev interface for facebook under "Roles", make sure that the test users are friends and then log in with each use on your app. Only then will they show up in the list.
Unless you ask for it specifically, your app will not have the user_friends permission (you do not, however, need to review this with Facebook as it is part of the basic permissions) - I added it to the onCreateView in the Splash Segment (from the Scrumptios/Login sample in the SDK) like this:
LoginButton loginButton = (LoginButton) view.findViewById(R.id.login_button);
loginButton.setReadPermissions(Arrays.asList("user_friends"));
Use the Facebook test user interface to login on facebook as your test user to validate that they have been accepting the correct permissions (under apps).

Android Could execute method of the activity

I'm building a simple paint app and encountering this error given by the logcat:
I'm using the following code:
This SaveDrawing.java serves as the main activity
package com.example.SaveDrawing;
import com.example.SaveDrawing.drawings.DrawingActivity;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
public class SaveDrawing extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
public void onClick(View view){
switch (view.getId()){
case R.id.drawBtn:
//Intent drawIntent = new Intent(this, DrawingActivity.class);
//startActivity( drawIntent);
//Toast.makeText(getBaseContext(), "This is the Toast message", Toast.LENGTH_SHORT).show();
Intent nextActivity = new Intent(SaveDrawing.this, DrawingActivity.class);
startActivity(nextActivity);
break;
}
}
}
Then the next activity after clicking the button is DrawingActivity.java
package com.example.SaveDrawing.drawings;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.Paint;
import android.graphics.Path;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.MotionEvent;
import android.view.View;
import android.widget.Button;
import java.io.File;
import java.io.FileOutputStream;
import com.example.SaveDrawing.R;
import com.example.SaveDrawing.R.id;
import com.example.SaveDrawing.R.layout;
public class DrawingActivity extends Activity implements View.OnTouchListener{
private DrawingSurface drawingSurface;
private DrawingPath currentDrawingPath;
private Paint currentPaint;
private Button redoBtn;
private Button undoBtn;
private static File APP_FILE_PATH = new File("/sdcard/TutorialForAndroidDrawings");
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.drawing_activity);
setCurrentPaint();
drawingSurface = (DrawingSurface) findViewById(R.id.drawingSurface);
drawingSurface.setOnTouchListener(this);
redoBtn = (Button) findViewById(R.id.redoBtn);
undoBtn = (Button) findViewById(R.id.undoBtn);
redoBtn.setEnabled(false);
undoBtn.setEnabled(false);
}
private void setCurrentPaint(){
currentPaint = new Paint();
currentPaint.setDither(true);
currentPaint.setColor(0xFFFFFF00);
currentPaint.setStyle(Paint.Style.STROKE);
currentPaint.setStrokeJoin(Paint.Join.ROUND);
currentPaint.setStrokeCap(Paint.Cap.ROUND);
currentPaint.setStrokeWidth(3);
}
public boolean onTouch(View view, MotionEvent motionEvent) {
if(motionEvent.getAction() == MotionEvent.ACTION_DOWN){
currentDrawingPath = new DrawingPath();
currentDrawingPath.paint = currentPaint;
currentDrawingPath.path = new Path();
currentDrawingPath.path.moveTo(motionEvent.getX(), motionEvent.getY());
currentDrawingPath.path.lineTo(motionEvent.getX(), motionEvent.getY());
}else if(motionEvent.getAction() == MotionEvent.ACTION_MOVE){
currentDrawingPath.path.lineTo(motionEvent.getX(), motionEvent.getY());
}else if(motionEvent.getAction() == MotionEvent.ACTION_UP){
currentDrawingPath.path.lineTo(motionEvent.getX(), motionEvent.getY());
drawingSurface.addDrawingPath(currentDrawingPath);
undoBtn.setEnabled(true);
redoBtn.setEnabled(false);
}
return true;
}
public void onClick(View view){
switch (view.getId()){
case R.id.colorRedBtn:
currentPaint = new Paint();
currentPaint.setDither(true);
currentPaint.setColor(0xFFFF0000);
currentPaint.setStyle(Paint.Style.STROKE);
currentPaint.setStrokeJoin(Paint.Join.ROUND);
currentPaint.setStrokeCap(Paint.Cap.ROUND);
currentPaint.setStrokeWidth(3);
break;
case R.id.colorBlueBtn:
currentPaint = new Paint();
currentPaint.setDither(true);
currentPaint.setColor(0xFF00FF00);
currentPaint.setStyle(Paint.Style.STROKE);
currentPaint.setStrokeJoin(Paint.Join.ROUND);
currentPaint.setStrokeCap(Paint.Cap.ROUND);
currentPaint.setStrokeWidth(3);
break;
case R.id.colorGreenBtn:
currentPaint = new Paint();
currentPaint.setDither(true);
currentPaint.setColor(0xFF0000FF);
currentPaint.setStyle(Paint.Style.STROKE);
currentPaint.setStrokeJoin(Paint.Join.ROUND);
currentPaint.setStrokeCap(Paint.Cap.ROUND);
currentPaint.setStrokeWidth(3);
break;
case R.id.undoBtn:
drawingSurface.undo();
if( drawingSurface.hasMoreUndo() == false ){
undoBtn.setEnabled( false );
}
redoBtn.setEnabled( true );
break;
case R.id.redoBtn:
drawingSurface.redo();
if( drawingSurface.hasMoreRedo() == false ){
redoBtn.setEnabled( false );
}
undoBtn.setEnabled( true );
break;
case R.id.saveBtn:
final Activity currentActivity = this;
Handler saveHandler = new Handler(){
#Override
public void handleMessage(Message msg) {
final AlertDialog alertDialog = new AlertDialog.Builder(currentActivity).create();
alertDialog.setTitle("Saved 1");
alertDialog.setMessage("Your drawing had been saved :)");
alertDialog.setButton("OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
return;
}
});
alertDialog.show();
}
} ;
new ExportBitmapToFile(this,saveHandler, drawingSurface.getBitmap()).execute();
break;
}
}
private class ExportBitmapToFile extends AsyncTask<Intent,Void,Boolean> {
private Context mContext;
private Handler mHandler;
private Bitmap nBitmap;
public ExportBitmapToFile(Context context,Handler handler,Bitmap bitmap) {
mContext = context;
nBitmap = bitmap;
mHandler = handler;
}
#Override
protected Boolean doInBackground(Intent... arg0) {
try {
if (!APP_FILE_PATH.exists()) {
APP_FILE_PATH.mkdirs();
}
final FileOutputStream out = new FileOutputStream(new File(APP_FILE_PATH + "/myAwesomeDrawing.png"));
nBitmap.compress(Bitmap.CompressFormat.PNG, 90, out);
out.flush();
out.close();
return true;
}catch (Exception e) {
e.printStackTrace();
}
//mHandler.post(completeRunnable);
return false;
}
#Override
protected void onPostExecute(Boolean bool) {
super.onPostExecute(bool);
if ( bool ){
mHandler.sendEmptyMessage(1);
}
}
}
}
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.SaveDrawing"
android:versionCode="1"
android:versionName="1.0">
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-sdk android:minSdkVersion="8" />
<application android:icon="#drawable/icon" android:label="#string/app_name">
<activity android:name=".SaveDrawing"
android:label="#string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".DrawingActivity" android:screenOrientation="landscape" ></activity>
<activity android:name=".drawings.DrawingActivity"/>
</application>
</manifest>
I have the following in my explorer. I'm not so sure if I got a wrong file structure.
Anyone can help me? I'm kinda new to java and android programming. Many thanks!!! :)

remove <activity android:name=".DrawingActivity" android:screenOrientation="landscape" ></activity> from your manifest as there is no such activity. there is only DrawingActivity in your project structure. Then clean build Run.
Also another possible problem could having an Activity Class name SaveDrawing in the package. You should try to rename the package, update relevant changes to the manifest and try running the app again..

You probably forgot to declare DrawingActivity in your manifest.xml

This is because you attempt to launch com.example.SaveDrawing.drawings/com.example.SaveDrawing.drawings.DrawingActivity,
but actual activity you launch in code is com.example.SaveDrawing/com.example.SaveDrawing.drawings.DrawingActivity
Please change
Intent nextActivity = new Intent(SaveDrawing.this, DrawingActivity.class);
to
Intent nextActivity = new Intent();
nextActivity.setClassName ("com.example.SaveDrawing.drawings", "com.example.SaveDrawing.drawings.DrawingActivity");
It might work.