Android java app installation under the hood

Question

I am trying to understand what exactly is going on when you install an application (APK) on an Android device. I guess that files are are extracted from the package and copied somewhere on the device.

• Are there other steps going on? For example, is the package name of the application written somewhere in the OS like in somekind of registry?
• Is the application version number written as well somewhere or the OS reads the xml manifest of the application to know its installed version?

This is related to another question where I suspect that some data was not erased correctly during the uninstallation of a debug app and I am trying to find what that might be.

Answer 1

There will be files/dirs created in various locations, not necessary in all possible locations for every app though, it depends on how the app is configured.

This list is not necessarily complete.

Files/dirs:

• /data/data
• /data/app
• /data/app-asec
• /data/app-lib
• /data/dalvik-cache
• /data/local/tmp
• /mnt/asec
• /mnt/obb
• /mnt/sdcard/Android/obb
• /mnt/sdcard/Android/data

Your app will also get an entry in these files:

• /data/system/packages.list
• /data/system/packages.xml
• /data/system/appops.xml