Question

I’d like to use a dependency injection framework.

During my evaluation I came to the conclusion that Google Guice seems to fit best for my demands.

However, some questions came into my mind:

1. Imagine a web application in which a user can have independent windows within a http session. The Session scope is too general while the Request scope is too narrow for me.
   Is there a scope which will help me out? (something I would call “window” or “controller instance” scope)

2. Are there any pitfalls writing a custom scope?

3. Our web application and several stand alone console applications are using the same classes. I am facing the problem that the scope of a class depends on the application type which is only known at runtime.
   E.g. in a standalone application the scope would be “No-Scope” or “per-Thread Scope“, while in a web application it would be bound to a Session/”window“.
   How to solve this problem?

Answer 1

1. You’ll have to create a custom scope
2. Not that I know. We’ve been using a custom scope and it works very well.
3. Have a different implementations of the custom scope being used in the web application and other for the standalone application