Android activity does not receive broadcast from local service

Question

From the examples, it looked simple. Maybe you can show me what I did wrong. I cannot get activity to receive broadcast sent from local service.

I have an Activity1 that starts Service1:

startService(new Intent(Activity1.this, Service1.class)); 

Action1 then starts Activity2:

 startActivity(new Intent(Activity1.this, Activity2.class)); 

Service1, the local service, listens for downloads:

 protected final BroadcastReceiver service2DownloadBroadcastReceiver = new BroadcastReceiver() { public void onReceive(final Context context, final Intent intent) { ... broadcastDownloadFinished(Uri.fromFile(downloadedFile)); 

Then the broadcast receiver Service1 transmits its message:

 protected Intent broadcastDownloadFinished(final Uri uri) { final Intent intent = new Intent(ACTION_DOWNLOAD_FINISHED).setData(checkNotNull(uri)); sendBroadcast(intent); 

Activity2, which is in the foreground at the time, listens for the ACTION_DOWNLOAD_FINISHED intent using its own broadcast receiver:

 private final BroadcastReceiver activity2DownloadBroadcastReceiver = new BroadcastReceiver() { public void onReceive(final Context context, final Intent intent) { Log.i(Activity2.class.getSimpleName(), "Received download event: " + intent.getAction() + " " + intent.getData()); 

Activity2, of course, registers the recipient:

 protected void onResume() { super.onResume(); final IntentFilter downloadIntentFilter = new IntentFilter(); downloadIntentFilter.addAction(ACTION_DOWNLOAD_FINISHED); registerReceiver(activity2DownloadBroadcastReceiver, downloadIntentFilter); 

In case it matters, ACTION_DOWNLOAD_FINISHED is something like "com.example.intent.action.DOWNLOAD_FINISHED" .

Service1 receives the boot manager event at its receiver and apparently broadcasts its own custom event, but Activity2 never receives it. What have I done wrong? Is it a problem of translating intent in the middle of processing another? (I wouldn’t think so - it is asynchronous, right?)

Update. To make sure that there is no problem sending the broadcast in the middle of receiving the broadcast, I changed my broadcast code to actually complete the broadcast after three seconds in the main stream:

  Log.i(getClass().getSimpleName(), "...ready to broadcast"); final Intent intent = new Intent(ACTION_DOWNLOAD_FINISHED).setData(checkNotNull(uri)); mainThreadHandler.postDelayed(new Runnable() { public void run() { Log.i(getClass().getSimpleName(), "...broadcasting"); sendBroadcast(intent); Log.i(getClass().getSimpleName(), "...broadcasted"); } }, 3000); Log.i(getClass().getSimpleName(), "...scheduled to broadcast"); 

As expected, the magazine says:

 ...ready to broadcast ...scheduled to broadcast ...broadcasting ...broadcasted 

However, nothing was received in the activity. Please, help.

Answer 1

Eureka! I found this! The problem is that I provided the data URI in my intent to translate. Android’s intent matching rules are a bit more complicated If you specify a data URI, then your intent filter should indicate the appropriate MIME type.

Unfortunately, although the Android documentation says that the data type can be inferred from the data URI, Android does not seem to know that the image file://.../example.jpg is an image. So this does not work:

 intentFilter.addDataType("image/*"); 

However, instead of specifying a type, I can specify a scheme that I accept:

 intentFilter.addDataScheme("file"); 

It works! It's a bit crude --- and a bit artificial to limit my broadcasts to file: URI, but since everything I'm using at the moment, it works.

Please note that, apparently, I could manually specify the MIME type in the intent when I broadcast it, but this is too much trouble, because I download images from Picasa, so I already know that they are images (and not caring for a particular type MIME). And if this entails too much trouble, I could completely drop the whole setData() thing and set an extra one, but of course I want to do everything right.

Answer 2

Have you included your receiver in your activity manifest?

 <receiver android:name=".YourReceiver"> <intent-filter> <action android:name="intent_name"></action> </intent-filter> </receiver>