Create a simulated Android environment within my application

Question

As the title says, I need to create a simulated Android environment within my app. I need to be able to install applications on this environment without installing them on the device.

I know it's possible because this app does it.

I've been searching for a while and I know the app does it by creating an Android environment, but I don't seem to find a lead on how to do it.

EDIT:

I found another app that can do it

Parallel Space

Answer 1

It depends to what degree you need to run the app and what constitutes "installing" the app. Keep in mind that an .apk file is just a java .jar file with some extra data tucked away in various places.

In order to run portions of an Android application without installing it, you will need to

1. Open and parse the apk. This APKParser class might be a good place to start.
2. Request any permissions which the app in question requires which aren't already requested by your app. In older versions of Android you would just have to request all possible permissions to start with, but with newer versions you can requestPermissions to make the actual permission request dialog when convenient.
3. Copy the classes.dex from the application into your data folder. If it uses any common classes which you also use, you'll probably want to nuke these out of the dex file so that you don't have class loading conflict, or else be very, very careful with class loaders.
4. Load the dex file with a DexFileLoader.
5. At this point you can load just about any code in the apk, but you won't be able to do a straight load of the Activities, since they're not defined in your AndroidManifest.xml. Instead, you'll need to create a "facade" Activity that hosts the actual activity in reflection and wires up things like the context into the reflected Activity.

These steps should probably work to run at least simple apps without installing them.