Develop Reference

Getting NULL in context while auto restart with BROADCAST RECEIVER in Android app

I am developing android application which need auto restart when restart device for that I am using broadcast receiver with action BOOT_COMPLETED.
Broadcast receiver is receiving message when I am restarting device but in restart method I want to start main activity for that I used Intent but in onReceive method of receiver I am getting null context so I am unable to restart main Activity.
Below is code for that.
MainActivity.java
private Object activity;
private TextView tvImeiNum;
private BroadcastReceiver rebootreceiver;
private IntentFilter filter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tvImeiNum = (TextView)findViewById(R.id.tv_imeinum);
filter = new IntentFilter();
filter.addAction(Intent.ACTION_BOOT_COMPLETED);
filter.addAction(Intent.ACTION_REBOOT);
rebootreceiver = new BootUpReceiver(MainActivity.this);
LocalBroadcastManager.getInstance(this).registerReceiver(rebootreceiver,
filter);//registering receiver
generateUniqueCode();
}
BootupReceiver.java
public class BootUpReceiver extends BroadcastReceiver {
MainActivity ma;
public BootUpReceiver(MainActivity maContext){
ma=maContext;
}
public BootUpReceiver(){
}
#RequiresApi(api = Build.VERSION_CODES.M)
#Override
public void onReceive(Context context, Intent intent) {
if (intent.getAction().equals("android.intent.action.BOOT_COMPLETED")) {
Log.d("TAG REBOOT", "onReceive: " + intent);
Log.d("Reboot complete", "connection");
GlobalTool.restartApplication(context);
}
}
}
GlobalTool.java
public class GlobalTool {
#RequiresApi(api = Build.VERSION_CODES.M)
public static void restartApplication(Context context) {
Log.d("IN App restart:", "");
Log.d("TAG", "restartApplication: ");
if(context != null)
{
Log.d("TAG NULL", "restartApplication: ");
Intent mainIntent = new Intent(context, MainActivity.class);
AlarmManager alarmMgr = (AlarmManager)
context.getSystemService(ALARM_SERVICE);
TaskStackBuilder stackBuilder = TaskStackBuilder.create(context);
stackBuilder.addNextIntent(mainIntent);
PendingIntent pendingIntent = stackBuilder.getPendingIntent(0,
PendingIntent.FLAG_UPDATE_CURRENT);
long alarmTime = System.currentTimeMillis() + (1 * 1000);
alarmMgr.setExact(AlarmManager.RTC_WAKEUP, alarmTime, pendingIntent);
Log.d("TAG", "restartApplication: 111");
Log.d("TAG", "restartApplication: 111");
}
else {
Intent mainIntent = new Intent(context, MainActivity.class);
AlarmManager alarmMgr = (AlarmManager)
context.getSystemService(ALARM_SERVICE);
TaskStackBuilder stackBuilder = TaskStackBuilder.create(context);
stackBuilder.addNextIntent(mainIntent);
PendingIntent pendingIntent = stackBuilder.getPendingIntent(0,
PendingIntent.FLAG_UPDATE_CURRENT);
long alarmTime = System.currentTimeMillis() + (1 * 1000);
alarmMgr.setExact(AlarmManager.RTC_WAKEUP, alarmTime, pendingIntent);
Log.d("TAG", "restartApplication: 111");
Log.d("TAG", "restartApplication: 111");
}
}
}
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
package="com.example.kioskappdemo">
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission
android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
<application
android:name="KioskApplication"
android:allowBackup="true"
android:dataExtractionRules="#xml/data_extraction_rules"
android:fullBackupContent="#xml/backup_rules"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:roundIcon="#mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="#style/Theme.KioskAppDemo"
tools:targetApi="31"
tools:ignore="Instantiatable">
<service
android:name=".RebootService"
android:enabled="true"
android:exported="true"></service>
<activity
android:name=".MainActivity"
android:exported="true"
android:screenOrientation="landscape"
android:theme="#style/Theme.AppCompat.NoActionBar">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category
android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<receiver
android:name=".Activity.BootUpReceiver"
android:enabled="true"
android:exported="true">
<intent-filter >
<action
android:name="android.intent.action.BOOT_COMPLETED" />
<action android:name="android.intent.action.REBOOT" />
<action
android:name="android.intent.action.QUICKBOOT_POWERON" />
<action android:name="com.reboot.test" />
<action
android:name="android.intent.action.TIMEZONE_CHANGED" />
<action
android:name="android.intent.action.DATE_CHANGED" />
</intent-filter>
</receiver>
</application>
</manifest>

Some you code improvements:
Don't put context to Brodcast Receiver constructor. Use the Context from onReceive method
public class BootUpReceiver extends BroadcastReceiver {
public BootUpReceiver(){
//TODO log
}
...
You should not use LocalBroadcastManager::registerReceiver call. If Broadcast receiver is added to AndroidManifest then it will be started by the system.
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
<receiver
android:name=".activity.BootUpReceiver"
android:enabled="true"
android:exported="true"
android:permission="android.permission.RECEIVE_BOOT_COMPLETED">
<intent-filter >
<action android:name="android.intent.action.BOOT_COMPLETED" />
</intent-filter>
</receiver>
Don't use CamelCase for package names (use .activity.BootUpReceiver insetad .Activity.BootUpReceiver)

reciever is not working when phone is restarted

I am using a Broadcast reciever to auto start my app whenever phone is switched on. But it is not working in my case. I am attaching the program details. Please somebody help me, where am I lagging behind. Thanks in advance
this is manifest file
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.vishal.readsimnumber">
<uses-permission android:name="android.permission.READ_PHONE_STATE" />
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
<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">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<receiver
android:name=".reciever.BootStartReciever">
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED" />
</intent-filter>
</receiver>
<service
android:name=".FetchSimNumber"
android:enabled="true"
android:exported="true"></service>
</application>
</manifest>
this is my broadcast reciever
public class BootStartReciever extends BroadcastReceiver {
public BootStartReciever() {
}
#Override
public void onReceive(Context context, Intent intent) {
if ("android.intent.action.BOOT_COMPLETED".equals(intent.getAction())) {
Intent pushIntent = new Intent(context, FetchSimNumber.class);
context.startService(pushIntent);
}
}
}
this is my service class
public class FetchSimNumber extends Service {
public FetchSimNumber() {
Intent intent = new Intent(FetchSimNumber.this,MainActivity.class);
startActivity(intent);
}
#Override
public IBinder onBind(Intent intent) {
// TODO: Return the communication channel to the service.
throw new UnsupportedOperationException("Not yet implemented");
}
}
and this is my main activity
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
TelephonyManager telemamanger = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
String getSimSerialNumber = telemamanger.getSimSerialNumber();
String getSimNumber = telemamanger.getLine1Number();
((TextView) findViewById(R.id.tv1)).setText(getSimSerialNumber);
((TextView) findViewById(R.id.tv2)).setText(getSimNumber);
}
}

public class BootStartReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
if (intent.getAction().equals("android.intent.action.BOOT_COMPLETED")) {
/* Setting the service here */
Intent i = new Intent(context, Yourservice.class)
context.startService(i);
}
and in your manifest file:
<receiver android:name=".BootReceiver"
android:enable="true">
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED" />
<category android:name="android.intent.category.HOME" />
</intent-filter>
</receiver>
sometimes category.HOME not work so you can use category.DEFAULT also.. i dont know the reason behind this, but its working fine..

AndroidManifest.xml
<receiver android:name=".Receiver">
<intent-filter android:priority="1000000">
<action android:name="android.intent.action.ACTION_SHUTDOWN" />
</intent-filter>
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED" />
<action android:name="android.intent.action.QUICKBOOT_POWERON" />
</intent-filter>
</receiver>
Receiver.xml
public class Receiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
if (intent.getAction().equalsIgnoreCase("android.intent.action.BOOT_COMPLETED")) {
**do your stuff at here...**
}
}

Broadcast receiver with wifi scan not working

I have the following code in a service which is called with an AlarmManager (this works well) but when when I start the wifi scan (which returns true) I never receive the results in the BroadcastReceiver I created:
public class WifiCheckerService extends IntentService {
WifiManager wifiManager;
List<Wifi> savedWifis;
List<Wifi> wifisInRange;
List<ScanResult> wifisInRangeResults;
BroadcastReceiver broadcastReceiver;
public WifiCheckerService() {
super("WifiCheckerService");
}
#Override
public void onCreate() {
super.onCreate();
setScanAlwaysAvailable();
if(broadcastReceiver == null)
broadcastReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
check();
}
};
if (wifiManager == null)
wifiManager = (WifiManager) getSystemService(Context.WIFI_SERVICE);
registerReceiver(broadcastReceiver,
new IntentFilter(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION));
}
#Override
protected void onHandleIntent(Intent intent) {
if (intent != null) {
wifiManager.startScan();
}
}
private void check() {
// irrelevant stuff
Intent intent = new Intent(Constants.BROADCAST_UPDATE_WIFI);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
sendBroadcast(intent);
}
}
public List<Wifi> getSavedWifisInRange(List<Wifi> savedWifis,
List<ScanResult> wifisInRangeResults) {
List<Wifi> wifisInRange = new ArrayList<Wifi>();
for (Wifi wifi : savedWifis) {
for (int i = 0; i < wifisInRangeResults.size(); i++) {
if (wifi.getSsid().equals(wifisInRangeResults.get(i).SSID)) {
wifi.setRssi(String.valueOf(wifisInRangeResults.get(i).level));
wifisInRange.add(wifi);
}
}
}
return wifisInRange;
}
public void setScanAlwaysAvailable() {
/* Set scan always available if it is turned off*/
WifiManager wifiManager = (WifiManager) getSystemService(Context.WIFI_SERVICE);
if (Build.VERSION.SDK_INT > Build.VERSION_CODES.JELLY_BEAN_MR2) {
if (!wifiManager.isScanAlwaysAvailable()) {
startActivity(new Intent(WifiManager.ACTION_REQUEST_SCAN_ALWAYS_AVAILABLE));
}
}
}
public boolean isTetheringActive() {
//irrelevant stuff
return false;
}
private boolean isAnySavedWifiInRange() {
//irrelevant stuff
return true;
}
#Override
public void onDestroy() {
super.onDestroy();
unregisterReceiver(wifiScanReceiver);
}
}
I have used BroadcastReceiver's with wifi scans before, but I don't know why this is not working.
What's wrong?
EDIT: AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_NETWORK_STATE" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.VIBRATE" />
<uses-permission android:name="android.permission.WAKE_LOCK" />
<uses-permission android:name="com.android.vending.BILLING" />
<application
android:name=".WifiSentinelApp"
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity
android:name=".activities.MainActivity"
android:label="#string/app_name"
android:screenOrientation="portrait"
android:theme="#style/AppTheme.NoActionBar">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".activities.DonateActivity"
android:label="#string/donate"
android:screenOrientation="portrait"
android:theme="#style/AppTheme.NoActionBar" />
<activity
android:name=".activities.SettingsActivity"
android:label="#string/settings"
android:screenOrientation="portrait" />
<receiver android:name=".receivers.AlarmReceiver" />
<receiver android:name=".receivers.BootReceiver"
android:enabled="false">
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED" />
</intent-filter>
</receiver>
<service android:name=".services.WifiCheckerService" />
</application>

My understanding of the IntentService is that it will only be active for the time needed to handle the request (ie, the time needed to run onHandleIntent()). I haven't tested your code, but my guess is that your broadcast receiver is being unregistered right away when onDestroy() runs, before the scan results are delivered. Probably an IntentService is not right for this. You might need to create a "regular" (long living background) service. Or, maybe it just makes more sense to have your BroadcastReceiver in the activity where you will show the scan results and get rid of this IntentService altogether. WifiManager::startScan() is asynchronous so it shouldn't be necessary to call that on a background service anyway.

No intent receiver set Urban AirShip

I do receive the push messages but whenever I click on them inside the notificationbar this logcat appears and the notification dissapears...
This is my logcat output:
05-31 16:49:47.165: D/Test - UALib(20523): No intent receiver set, not sending ACTION_NOTIFICATION_OPENED
Here is my manifest structure:
<category android:name="com.test.push" />
</intent-filter>
</receiver>
<service
android:name="com.urbanairship.push.PushService"
android:label="Push Notification Service" />
<service
android:name="com.urbanairship.push.PushWorkerService"
android:label="Push Notification Worker Service" />
<service
android:name="com.urbanairship.analytics.EventService"
android:label="Event Service" />
<provider
android:name="com.urbanairship.UrbanAirshipProvider"
android:authorities="com.test.push.urbanairship.provider"
android:exported="false"
android:multiprocess="true" />
<activity
android:name="com.test.push.MainActivity"
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="com.test.push.SettingsActivity"
android:label="#string/title_activity_settings" />
<activity
android:name="com.test.push.ChooseClass"
android:label="#string/app_name" />
</application>
This here is my MyApplication.java:
public class MyApplication extends Application {
#Override
public void onCreate() {
AirshipConfigOptions options = AirshipConfigOptions
.loadDefaultOptions(this);
options.developmentAppKey = "1234567890";
options.developmentAppSecret = "1234567890";
options.productionAppKey = "";
options.productionAppSecret = "";
options.gcmSender = "1234567890";
options.transport = "gcm";
options.inProduction = false;
UAirship.takeOff(this, options);
PushManager.enablePush();
}
}
And this is my IntentReceiver.java:
public class IntentReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context aContext, Intent aIntent) {
String action = aIntent.getAction();
if (action.equals(PushManager.ACTION_PUSH_RECEIVED)) {
logPushExtras(aIntent);
} else if (action.equals(PushManager.ACTION_NOTIFICATION_OPENED)) {
logPushExtras(aIntent);
Intent launch = new Intent(Intent.ACTION_MAIN);
launch.setClass(UAirship.shared().getApplicationContext(),
MainActivity.class);
launch.putExtra("push_message",
aIntent.getStringExtra(PushManager.EXTRA_ALERT));
launch.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
UAirship.shared().getApplicationContext().startActivity(launch);
} else if (action.equals(PushManager.ACTION_REGISTRATION_FINISHED)) {
Logger.info("device registrated, APID="
+ aIntent.getStringExtra(PushManager.EXTRA_APID)
+ ", valid="
+ aIntent.getBooleanExtra(
PushManager.EXTRA_REGISTRATION_VALID, false));
}
}
private void logPushExtras(Intent intent) {
Set<String> keys = intent.getExtras().keySet();
for (String key : keys) {
List<String> ignoredKeys = (List<String>) Arrays.asList(
"collapse_key", "from", PushManager.EXTRA_NOTIFICATION_ID,
PushManager.EXTRA_PUSH_ID, PushManager.EXTRA_ALERT);
if (ignoredKeys.contains(key)) {
continue;
}
}
}
}

The problem was, I was missing the following line inside my MyApplication.java file:
PushManager.shared().setIntentReceiver(IntentReceiver.class);
All the rest was correct. It's now working perfectly.

And i was missing to specify Application's android:name attribute in my manifest file-
<application
android:allowBackup="true"
android:icon="#drawable/app_icon"
android:label="#string/app_name"
android:theme="#style/AppTheme"
android:allowClearUserData="true"
android:enabled="true"
android:name=".MyMainApplication">
<activity>
Some Activity
</activity>
</application>

Run a task in background always in android

I have a problem that I made a service which executes a task in background after every 5 seconds, for this I made a receiver in manifest and autostarter class but it is not excuted in my app. Means the service is not running in the app. I don't know why? Please suggest me for the right answer.
Android Manifest:
<application android:icon="#drawable/icon" android:label="#string/app_name">
<receiver android:name="com.halosys.TvAnyTime.ServiceAutoStarter">
<intent-filter>
<action android:name="android.intent.action.BOOT_COMPLETED" />
</intent-filter>
</receiver>
<activity android:name=".MainScreen"
android:label="#string/app_name" android:screenOrientation="portrait" android:theme="#android:style/Theme.NoTitleBar">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".IntroVideo" android:label="#string/app_name" android:theme="#style/CustomTheme" android:screenOrientation="landscape"/>
<activity android:name=".WelcomeScreen1" android:theme="#android:style/Theme.NoTitleBar" android:screenOrientation="portrait"/>
<activity android:name=".IntroFaceBookScreen" android:theme="#android:style/Theme.NoTitleBar" android:screenOrientation="portrait"/>
</application>
<uses-permission xmlns:android="http://schemas.android.com/apk/res/android"
android:name="android.permission.INTERNET"></uses-permission>
<uses-permission android:name="android.permission.CHANGE_WIFI_MULTICAST_STATE"/>
<uses-permission android:name="android.permission.READ_INPUT_STATE"></uses-permission>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.READ_PHONE_STATE"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_MOCK_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
<uses-sdk android:minSdkVersion="3" />
</manifest>
ServiceAutoStarter:
public class ServiceAutoStarter extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
Intent myIntent = new Intent(context, ServiceTemplate.class);
myIntent.putExtra("extraData", "somedata");
context.startService(myIntent);
}
}
ServiceTemplate.java:
public class ServiceTemplate extends Service {
Runnable refresher;
public static int HashesInPattern=32; // 32 64byte hashes in the pattern
public static int BytesInHash =64;
static byte[] hashPattern;
ArrayList<byte[]> finalHashafterXor = new ArrayList<byte[]>();
byte[] finaldatafile = new byte[2097152];
byte[] finalhash;
InputStream is;
byte[] bytesafterXor,bytes;
String strLine;
#Override
public IBinder onBind(Intent intent) {
return null;
}
#Override
public void onCreate() {
//code to execute when the service is first created
}
#Override
public void onDestroy() {
//code to execute when the service is shutting down
}
#Override
public void onStart(Intent intent, int startid) {
//code to execute when the service is starting up
final Handler handler = new Handler();
refresher = new Runnable() {
public void run() {
// some action
try{
Encrypt();
Toast.makeText(getApplicationContext(), "Hello World", Toast.LENGTH_SHORT).show();
}
catch(Exception e)
{
e.printStackTrace();
}
handler.postDelayed(refresher, 2000);
}
};
}
Thanks in advance.

I haven't gone through whole of your code but i saw manifest file
Like activities (and other components), you must declare all services in your application's manifest file.
Please do change and try.