Develop Reference

Why does this explicit broadcast not work?

I am trying to send an explicit broadcast to a receiver that's dynamically registered inside an activity but it doesn't seem to work. I've tried adding the action that the intent filter is expecting but that doesn't work either. Only when I use a public implicit intent it picks up the broadcast.
Could any one tell me why? The code is for Android 8.0+ and I have marked the line inside CustomReceiver.
In summary it should...
Service starts, dynamically registers a CustomReceiver to listen for a implicit broadcast.
CustomReceiver receives implicit broadcast, tries to send explicit broadcast to MainActivity.
MainActivity receiver catches the explicit broadcast and does something.
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.demos.democode">
<uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
<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=".CustomService" />
</application>
</manifest>
MainActivity.java
package com.demos.democode;
import androidx.appcompat.app.AppCompatActivity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.util.Log;
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
IntentFilter intentFilter = new IntentFilter(CustomService.customActionActivity);
getApplicationContext().registerReceiver(activityReceiver, intentFilter);
Intent serviceIntent = new Intent(this,CustomService.class);
this.startForegroundService(serviceIntent);
Log.d("DEMO_APP", "create");
}
BroadcastReceiver activityReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
Log.d("DEMO_APP", "activity receiver");
}
};
}
CustomReceiver.java - Explicit broadcast from here doesn't work.
package com.demos.democode;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.util.Log;
public class CustomReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
Log.d("DEMO_APP", "custom receiver");
// DOESN'T WORK! this explicit broadcast doesn't work even after setting an action in - why?
Intent i = new Intent(context, MainActivity.class);
i.setAction(CustomService.customActionActivity);
context.sendBroadcast(i);
// this implicit public broadcast works fine
i = new Intent(CustomService.customActionActivity);
context.sendBroadcast(i);
}
}
CustomService.java
package com.demos.democode;
import android.app.Notification;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.IBinder;
import android.util.Log;
import androidx.annotation.Nullable;
import androidx.core.app.NotificationCompat;
import androidx.core.app.NotificationManagerCompat;
public class CustomService extends Service {
protected Context context = null;
public static String customAction = "EVENT_1";
public static String customActionActivity = "EVENT_2";
#Override
public void onCreate() {
super.onCreate();
context = getApplicationContext();
NotificationChannel serviceChannel = new NotificationChannel(
"DEMO_CHANNEL",
"Demo App",
NotificationManager.IMPORTANCE_LOW
);
NotificationManager manager = getSystemService(NotificationManager.class);
manager.createNotificationChannel(serviceChannel);
Notification notification = new NotificationCompat.Builder(context, "DEMO_CHANNEL")
.setSmallIcon(R.drawable.ic_launcher_foreground)
//.setContentText("Total screen time today: " + totalTimeDisplay )
.build();
NotificationManagerCompat notificationManager = NotificationManagerCompat.from(context);
notificationManager.notify(1, notification);
startForeground(1, notification);
IntentFilter intentFilter = new IntentFilter(customAction);
CustomReceiver customReceiver = new CustomReceiver();
context.registerReceiver( customReceiver , intentFilter);
Log.d("DEMO_APP", "service created");
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
final Intent i = new Intent(customAction);
Log.d("DEMO_APP", "service started");
sendBroadcast(i);
return Service.START_NOT_STICKY;
}
#Override
public void onDestroy() {
super.onDestroy();
}
#Nullable
#Override
public IBinder onBind(Intent intent) {
return null;
}
}

You are trying to launch an Activity using sendBroadcast()
In this code:
// DOESN'T WORK! this explicit broadcast doesn't work even after setting an action in - why?
Intent i = new Intent(context, MainActivity.class);
i.setAction(CustomService.customActionActivity);
context.sendBroadcast(i);
You are trying to launch an Activity, so the last line needs to be:
content.startActivity(i);

Sorry I am rather late to the party, but I think the error is in registration of receiver in the MainActivity. You have used
getApplicationContext().registerReceiver(activityReceiver, intentFilter);
Which is using application context to register receiver.
It should be replaced by:
registerReceiver(activityReceiver, intentFilter);
In which the receiver will be registered for that specific activity instance of Context.

Broadcast receiver not working in background

I am creating a app which can detetct incomming sms to android phone but app is not working in background.
Here is my mainactivity.java in which i am asking for the permission from user to allow access to read sms.
package com.example.times;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;
import android.Manifest;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.widget.Switch;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
private static final int READ_SMS_PERMISSION=0;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (ContextCompat.checkSelfPermission(this, Manifest.permission.RECEIVE_SMS) != PackageManager.PERMISSION_GRANTED)
{
if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.RECEIVE_SMS))
{
// do nothing
}
else
{
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.RECEIVE_SMS}, READ_SMS_PERMISSION);
}
}
}
#Override
public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults)
{
switch(requestCode)
{
case READ_SMS_PERMISSION:
{
if(grantResults.length>0 && grantResults[0]==PackageManager.PERMISSION_GRANTED)
{
Toast.makeText(this, "Thankyou for granting access", Toast.LENGTH_LONG).show();
}
else
{
Toast.makeText(this, "No problem", Toast.LENGTH_LONG).show();
}
}
}
}
}
Here is myreciver.java in which i am detecting incomming sms and making toast of that msg.
When app is opened then it is working properly but when i exit the app it is not detecting any sms.
package com.example.times;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.os.Build;
import android.os.Bundle;
import android.telephony.SmsMessage;
import android.util.Log;
import android.widget.Toast;
public class MyReceiver extends BroadcastReceiver {
private static final String SMS_RECEIVED="android.provider.Telephony.SMS_RECEIVED";
private static final String TAG="SmsBroadcastReceiver";
String msg, phoneNo ="";
#Override
public void onReceive(Context context, Intent intent) {
// TODO: This method is called when the BroadcastReceiver is receiving
// an Intent broadcast.
// throw new UnsupportedOperationException("Not yet implemented");
Log.i(TAG, "Intent Received: " +intent.getAction());
if (intent.getAction()==SMS_RECEIVED)
{
Bundle dataBundle = intent.getExtras();
if (dataBundle!=null)
{
Object[] mypdu=(Object[])dataBundle.get("pdus");
final SmsMessage[] message = new SmsMessage[mypdu.length];
for (int i =0; i<mypdu.length; i++)
{
if (Build.VERSION.SDK_INT>=Build.VERSION_CODES.M)
{
String format= dataBundle.getString("format");
message[i] = SmsMessage.createFromPdu((byte[])mypdu[i],format);
}
else
{
message[i] = SmsMessage.createFromPdu((byte[]) mypdu[i]);
}
msg =message[i].getMessageBody();
phoneNo= message[i].getOriginatingAddress();
}
Toast.makeText(context, "Message: " +msg +"\nNumber: " +phoneNo, Toast.LENGTH_SHORT).show();
}
}
}
}
Telll me if i am doing something wrong.

Make sure you have these in your Android Mainfest.xml
<uses-permission android:name="android.permission.SEND_SMS" />
<uses-permission android:name="android.permission.RECEIVE_SMS" />
And the following
<receiver
android:name=
"com.example.times.MyReceiver"
android:enabled="true"
android:exported="true">
</receiver>
EDIT
You need an Intent Service to read sms while your app is closed or in background.
Intent Service - Run in Background
Steps:
Create Intent Service
Add it Manifest
Call it from your Broadcast Receiver onReceive() method via Intent

bindService android AIDL always return false

I would like to provide a service that can be called by other app. Therefore, I have a service and an aidl. But when I try to have a separate application to bind this service (bindService), it just returns me false which means fail. Here is my code.
I'm using the code from books Pro Android 2
I've already tried many solutions in other questions similar to this, but there isn't any working solution for me.
I've tried fix the aidl intent filter but it's still not working
I've tried fix the package name and class name in client app, but it's still not working.
Please help me!
On Client :
// IStockQuoteService.aidl
package id.ac.ui.cs.mobileprogramming.ahmad_fauzan_amirul_isnain.stockquoteservice;
// Declare any non-default types here with import statements
interface IStockQuoteService {
double getQuote(String ticker);
}
package id.ac.ui.cs.mobileprogramming.ahmad_fauzan_amirul_isnain.stockquoteclient;
import id.ac.ui.cs.mobileprogramming.ahmad_fauzan_amirul_isnain.stockquoteservice.IStockQuoteService;
import android.app.Activity;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.IBinder;
import android.os.RemoteException;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;
public class MainActivity extends Activity {
protected static final String TAG = "StockQuoteClient";
private IStockQuoteService stockService = null;
private Button bindBtn;
private Button callBtn;
private Button unbindBtn;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
bindBtn = (Button)findViewById(R.id.bindBtn);
bindBtn.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View view) {
Intent intent = new Intent();
intent.setClassName("com.id.ac.ui.cs.mobileprogramming" +
".ahmad_fauzan_amirul_isnain.stockquoteservice",
"com.id.ac.ui.cs.mobileprogramming.ahmad_fauzan_amirul_isnain" +
".stockquoteservice.IStockQuoteService");
Log.d("Hasil", String.valueOf(bindService(intent,
serConn, Context.BIND_AUTO_CREATE)));
bindBtn.setEnabled(false);
callBtn.setEnabled(true);
unbindBtn.setEnabled(true);
}});
callBtn = (Button)findViewById(R.id.callBtn);
callBtn.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View view) {
callService();
}});
callBtn.setEnabled(false);
unbindBtn = (Button)findViewById(R.id.unbindBtn);
unbindBtn.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View view) {
unbindService(serConn);
bindBtn.setEnabled(true);
callBtn.setEnabled(false);
unbindBtn.setEnabled(false);
}});
unbindBtn.setEnabled(false);
}
private void callService() {
try {
double val = stockService.getQuote("SYH");
Toast.makeText(MainActivity.this, "Value from service is "+val,
Toast.LENGTH_SHORT).show();
} catch (RemoteException ee) {
Log.e("MainActivity", ee.getMessage(), ee);
}
}
private ServiceConnection serConn = new ServiceConnection() {
#Override
public void onServiceConnected(ComponentName name, IBinder service)
{
Log.v(TAG, "onServiceConnected() called");
stockService = IStockQuoteService.Stub.asInterface(service);
callService();
}
#Override
public void onServiceDisconnected(ComponentName name) {
Log.v(TAG, "onServiceDisconnected() called");
stockService = null;
}
};
}
On Service :
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="id.ac.ui.cs.mobileprogramming.ahmad_fauzan_amirul_isnain.stockquoteservice">
<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="StockQuoteService">
<intent-filter>
<action android:name="com.id.ac.ui.cs.mobileprogramming.ahmad_fauzan_amirul_isnain.stockquoteservice.IStockQuoteService"
/>
</intent-filter>
</service>
</application>
</manifest>
package id.ac.ui.cs.mobileprogramming.ahmad_fauzan_amirul_isnain.stockquoteservice;
import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.os.RemoteException;
import android.util.Log;
public class StockQuoteService extends Service
{
private static final String TAG = "StockQuoteService";
public class StockQuoteServiceImpl extends IStockQuoteService.Stub
{
#Override
public double getQuote(String ticker) throws RemoteException
{
Log.v(TAG, "getQuote() called for " + ticker);
return 20.0;
}
}
#Override
public void onCreate() {
super.onCreate();
Log.v(TAG, "onCreate() called");
}
#Override
public void onDestroy()
{
super.onDestroy();
Log.v(TAG, "onDestroy() called");
}
#Override
public void onStart(Intent intent, int startId) {
super.onStart(intent, startId);
Log.v(TAG, "onStart() called");
}
#Override
public IBinder onBind(Intent intent)
{
Log.v(TAG, "onBind() called");
return new StockQuoteServiceImpl();
}
}
// IStockQuoteService.aidl
package id.ac.ui.cs.mobileprogramming.ahmad_fauzan_amirul_isnain.stockquoteservice;
// Declare any non-default types here with import statements
interface IStockQuoteService {
double getQuote(String ticker);
}

I'm using the code from books Pro Android 2
That book is from 2010. Much of that book will be out of date. Please use something newer. If nothing else, you can download older editions of one of my books for free. Right now, the most recent version of those is from 2015 — while that too is a bit old, it is much more up to date than a book from 2010.
I've already tried many solutions in other questions similar to this, but there isn't any working solution for me.
You have:
intent.setClassName("com.id.ac.ui.cs.mobileprogramming" +
".ahmad_fauzan_amirul_isnain.stockquoteservice",
"com.id.ac.ui.cs.mobileprogramming.ahmad_fauzan_amirul_isnain" +
".stockquoteservice.IStockQuoteService");
The package in your manifest has id.ac.ui.cs.mobileprogramming.ahmad_fauzan_amirul_isnain.stockquoteservice. Assuming that your applicationId in your module's build.gradle file is the same, I think that this matches what you have in your code. Your application ID is very long — in the future, I recommend that you use something shorter and easier to visually compare.
However, your class name is wrong. Your <service> class is StockQuoteService, not IStockQuoteService. IStockQuoteService is the name of the AIDL, not the service, and your Intent needs to point to the service. So, try:
intent.setClassName("com.id.ac.ui.cs.mobileprogramming" +
".ahmad_fauzan_amirul_isnain.stockquoteservice",
"com.id.ac.ui.cs.mobileprogramming.ahmad_fauzan_amirul_isnain" +
".stockquoteservice.StockQuoteService");
Or, to reduce duplication:
String packageName = "com.id.ac.ui.cs.mobileprogramming" +
".ahmad_fauzan_amirul_isnain.stockquoteservice";
intent.setClassName(packageName, packageName+".StockQuoteService");

Geocoder IntentService is not being called

I understand this questions has been asked many times, for each question that has already been asked, the implementation is different from mine. The method I used create and call the intentService for a geocoder, was used from the android dev tutorial site.
https://developer.android.com/training/location/display-address.html.
I have gone over the the tutorial 3 times over to make sure I wasn't missing anything, but it is clear that I am.
Here is my manifest file, I have added the location and internet permissions.
<?xml version="1.0" encoding="utf-8"?>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<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=".selectRouteAndTransportMethod">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
<service
android:name=".FetchAddressIntentService"
android:exported="false"/>
</activity>
<!--
The API key for Google Maps-based APIs is defined as a string resource.
(See the file "res/values/google_maps_api.xml").
Note that the API key is linked to the encryption key used to sign the APK.
You need a different API key for each encryption key, including the release key that is used to
sign the APK for publishing.
You can define the keys for the debug and release targets in src/debug/ and src/release/.
-->
<meta-data
android:name="com.google.android.geo.API_KEY"
android:value="#string/google_maps_key" />
<activity
android:name="user.com.commuterapp.MapsActivity"
android:label="#string/title_activity_maps"></activity><!-- ATTENTION: This was auto-generated to add Google Play services to your project for
App Indexing. See https://g.co/AppIndexing/AndroidStudio for more information. -->
<meta-data
android:name="com.google.android.gms.version"
android:value="#integer/google_play_services_version" />
</application>
Here is my main activity: All I am doing here is using a buttonClick to create the intent and to start the intent.
package user.com.commuterapp;
import android.app.PendingIntent;
import android.content.Intent;
import android.net.Uri;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.location.LocationServices;
import user.com.commuterapp.R;
import static java.lang.Boolean.TRUE;
public class selectRouteAndTransportMethod extends AppCompatActivity {
Intent mIntent;
PendingIntent mPendingIntent;
myLocation mCurrentLocation;
private AddressResultReceiver mResultReceiver;
public static final String TAG = selectRouteAndTransportMethod.class.getSimpleName();
/**
* ATTENTION: This was auto-generated to implement the App Indexing API.
* See https://g.co/AppIndexing/AndroidStudio for more information.
*/
private GoogleApiClient client;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_select_route_and_transport_method);
mIntent = new Intent(this, selectRouteAndTransportMethod.class);
mPendingIntent = PendingIntent.getActivity(this, 0, mIntent, 0);
mCurrentLocation = new myLocation(this, this, mPendingIntent);
// ATTENTION: This was auto-generated to implement the App Indexing API.
// See https://g.co/AppIndexing/AndroidStudio for more information.
}
#Override
protected void onStart() {
super.onStart();
Log.d(TAG, "On Start");
mCurrentLocation.connect();
boolean connecting = mCurrentLocation.mGoogleApiClient.isConnecting();
boolean registered = mCurrentLocation.mGoogleApiClient.isConnectionCallbacksRegistered(mCurrentLocation);
//ConnectionResult connectionResult = mCurrentLocation.mGoogleApiClient.getConnectionResult(LocationServices.API);
if (connecting == TRUE) {
Log.d(TAG, "Connecting");
}
if (registered == TRUE) {
Log.d(TAG, "registered");
}
}
#Override
protected void onResume() {
super.onResume();
mCurrentLocation.connect();
}
#Override
protected void onPause() {
super.onPause();
// mCurrentLocation.disconnect();
}
protected void buttonOriginClick(View view)
{
Log.d(TAG,"retrieving address");
retrieveAddress();
}
protected void retrieveAddress() {
Intent geoCoderIntent = new Intent(this, FetchAddressIntentService.class);
geoCoderIntent.putExtra(FetchAddressIntentService.Constants.RECIEVER, mResultReceiver);
geoCoderIntent.putExtra(FetchAddressIntentService.Constants.LOCATION_DATA_EXTRA, mCurrentLocation.mCurrentLocation);
startService(geoCoderIntent);
}
}
And lastly here is the intentService class. This was straight out of the android dev tutorial site, nothing original here.
package user.com.commuterapp;
import android.app.IntentService;
import android.content.Intent;
import android.location.Address;
import android.location.Geocoder;
import android.location.Location;
import android.os.Bundle;
import android.support.v4.os.ResultReceiver;
import android.text.TextUtils;
import android.util.Log;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;
import static android.content.ContentValues.TAG;
/**
* Created by User on 1/21/2017.
*/
public class FetchAddressIntentService extends IntentService {
public final class Constants{
public static final int SUCCESS_RESULT = 0;
public static final int FAILURE_RESULT = 1;
public static final String PACKAGE_NAME =
"user.com.commuterapp";
public static final String RECIEVER = PACKAGE_NAME +
".RECIEVER";
public static final String RESULT_DATA_KEY = PACKAGE_NAME + ".RESULT_DATA_KEY";
public static final String LOCATION_DATA_EXTRA = PACKAGE_NAME +
".LOCATION_DATA_EXTRA";
}
protected ResultReceiver mReceiver;
public FetchAddressIntentService()
{
super("FetchAddressIntentService");
}
private void deliverResultToReceiver(int resultCode, String message){
Bundle bundle = new Bundle();
bundle.putString(Constants.RESULT_DATA_KEY, message);
mReceiver.send(resultCode,bundle);
}
#Override
protected void onHandleIntent (Intent intent) {
Log.d(TAG, "GeoCoder Service Started");
Geocoder geocoder = new Geocoder(this, Locale.getDefault());
String errorMessage = "";
Location location = intent.getParcelableExtra(Constants.LOCATION_DATA_EXTRA);
List<Address> addresses = null;
try {
addresses = geocoder.getFromLocation(
location.getLongitude(),
location.getLatitude(),
1);
}catch (IOException ioException) {
//catch network or other I/O Problems
errorMessage = getString(R.string.service_not_available);
Log.e(TAG, errorMessage);
} catch (IllegalArgumentException illegalArgumentException){
//catch invalid latitude or longitude values
errorMessage = getString(R.string.invalid_lat_long_used);
Log.e(TAG, errorMessage + "." + "Latitude =" + location.getLatitude()
+ ", Longitude = " + location.getLongitude(),
illegalArgumentException);
}
//handle cases where no addresses was foudn
if (addresses == null || addresses.size() == 0)
{
if(errorMessage.isEmpty()){
errorMessage = getString(R.string.no_address_found);
Log.e(TAG,errorMessage);
}
deliverResultToReceiver(Constants.FAILURE_RESULT, errorMessage);
}else
{
Address address = addresses.get(0);
ArrayList<String> addressFragments = new ArrayList<String>();
//Fetch the address lines using getAddressLine
//join them and send them to the thread
for(int i = 0; i < address.getMaxAddressLineIndex(); i++){
addressFragments.add(address.getAddressLine(i));
}
Log.i(TAG, getString(R.string.address_found));
deliverResultToReceiver(Constants.SUCCESS_RESULT,
TextUtils.join(System.getProperty("line.seperator"), addressFragments));
}
}
}
EDIT: I have tried rewriting the geocoder following the instructions from the android dev site again, but no success.
EDIT2: I noticed in the manifest I declared the service, within the application declaration, instead of outside, I made the change but to no avail, any insights will be appreciated

How to start NotificationListenerService?

Today I started writing for android. I want a simple (I think) app that waits for notification with specified title and then does something. I tried this code for service
import android.app.NotificationManager;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.service.notification.NotificationListenerService;
import android.service.notification.StatusBarNotification;
import android.util.Log;
import android.support.v4.content.LocalBroadcastManager;
import android.widget.Toast;
public class NotificationListener extends NotificationListenerService {
Context context;
public int onStartCommand(Intent intent, int flags, int startId) {
// Let it continue running until it is stopped.
Toast.makeText(this, "Service Started", Toast.LENGTH_LONG).show();
return START_STICKY;
}
#Override
public void onCreate() {
Toast.makeText(this, "onCreate", Toast.LENGTH_LONG).show();
super.onCreate();
context = getApplicationContext();
}
#Override
public void onNotificationPosted(StatusBarNotification sbn) {
String pack = sbn.getPackageName();
Toast.makeText(this,"NOTIFICATION",Toast.LENGTH_SHORT).show();
String text = "";
String title = "";
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.KITKAT) {
Bundle extras = extras = sbn.getNotification().extras;
text = extras.getCharSequence("android.text").toString();
title = extras.getString("android.title");
}
Log.i("Package",pack);
Log.i("Title",title);
Log.i("Text",text);
}
#Override
public void onNotificationRemoved(StatusBarNotification sbn) {
Toast.makeText(this,"NOTIFICATION removed",Toast.LENGTH_SHORT).show();
Log.i("Msg","Notification was removed");
}
}
Then added this to manifest:
<service
android:name=".NotificationListener"
android:enabled="true"
android:label="#string/app_name"
android:permission="android.permission.BIND_NOTIFICATION_LISTENER_SERVICE">
<intent-filter>
<action android:name="android.service.notification.NotificationListenerService" />
</intent-filter>
</service>
finally started the service in MainActivity onCreate() startService(new Intent(context, NotificationListener.class));
onNotificationPosted does not work. It seems like service was started correctly, because toasts from onStartCommand and onCreate were shown. I tried on emulator and real device. I also allowed notification access in settings. Please help, I wasted 5 hours on that.