Question

I want to add a non-native shared library to Android so every application on the device would be able to use it. I mean using packaged classes just like a core library as if they were present in the application itself.

I studied Android source code to figure out a way to add a new path to the application ClassLoader and found out that it is created during startup and there’s no way to change the paths later. I can use my own ClassLoader, but all I will get after loading a class will be a reference to a Class object. This way I will be bound to work through reflection mechanism, which is slower than the native execution system.

Is there any way to organise a shared library on Android?

Update: just to be clear here, I don’t need interaction between applications. I need classes which I can reuse in any application. Also static libraries don’t really suit my needs because this will bloat the applications.

Answer 1

Recent post on the Android blog explains exactly what I needed:

The Dalvik VM provides facilities for developers to perform custom class loading. Instead of loading Dalvik executable (“dex”) files from the default location, an application can load them from alternative locations such as internal storage or over the network.

The key is to use DexClassLoader to load the needed library. After that the code can be accessed either through interfaces, or by using reflection.