I have just released SDI - Simple Dependency Injection framework.
It is really light and does not enforce anything on a user, does not use annotations, or any kind of XML. It helps also with structuring the code by separating creation logic from business logic.
Full Java implementation is less than 300 LOC of code.
Currently, it is implemented in Java only, but if you find it interesting I will create Scala version also.
Please let me know your comments and suggestions.
And for sure let me know if you want it in Scala