I think there's a bit of chicken-and-egg confusion happening here -
specifically: Modules are things which set up bindings, which can *later*
be used for injection. The injector, which does the injecting, is
*created* using the modules.
It looks like you are trying to get things injected *into* your module,
which doesn't really make sense, because the injector that would do that
doesn't exist yet, and won't exist until your module exists - by which time
it is already constructed (yes, you could create an injector that creates
some more modules and then create an injector over them so it's turtles all
the way down, but these sorts of contortions become unreadable quickly).
Think of it this way: Guice adds an explicit "initialization" phase to
your application - think of it like running a meta-constructor for your
whole application. Modules' configure() methods are the code that runs
inside that constructor.
If you need to load some configuration that will affect how things are
bound - you need to pass some arguments into that "meta-constructor" - then
you need some mechanism (such as reading a file, looking at environment
variables, parsing command-line arguments - whatever suits you), but it's
not going to be injection because the injector doesn't exist yet.
A straightforward form of this would be to do something like:
Properties p = //load some properties file
for (String key : p.stringPropertyNames()) {
bind
(String.class).annotatedWith(Names.named(key)).toInstance(p.getProperty(key));
// or bindConstant or whatever
}
but has the nasty side-effect that if a property is missing from the file
and some object needs it, a runtime exception will be thrown, probably when
you don't expect it. The library I pointed you at, at its heart, does more
or less what the code above does, but with provisions for providing default
values, standard filesystem locations for the file, automatic refresh, and
ways to namespace classes or packages to load from different files/urls.
The point is, it sounds like you're looking for something to be injected
into a module, but at the time your module is created, the injector does
not exist - and while there might be hacky ways to convince Guice to do
something like that, it's probably not a good idea - better to keep it
simple.
-Tim
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