Android development notes.#

Reading closed binary apk's.#

Unzipping most of your apk's on your device, you will find, that you cannot read even the AndroidManifest.xml file.
Well, use the apktool to decompile it, and see if you can learn something from it.

Here's an example :

metskem@gneisenau:~/AndroidStuff/misc$ ./apktool d --no-src apps/aokp-5.2/nl.ns.android.activity-1.apk apps/decoded/ns
I: Copying raw classes.dex file...
I: Loading resource table...
I: Loaded.
I: Loading resource table from file: /home/metskem/apktool/framework/1.apk
I: Loaded.
I: Decoding file-resources...
I: Decoding values*/* XMLs...
I: Done.
I: Copying assets and libs...

#

C2DM

C2DM, or Cloud to Device Messaging, can be used to send small messages from a server to an Android device, see https://developers.google.com/android/c2dm/ for all details. You could use it to tell an app to come and get updates or new data.
An application on an Android device doesn’t need to be running to receive messages. The system will wake up the application via Intent broadcast when the the message arrives...

Here is the diagram: