Scoped providers in Guice

Question

Does scoping work on Guice providers? Suppose I have a FooProvider and bind like thus:

bind(Foo.class).toProvider(FooProvider.class).inScope(ServletScopes.REQUEST)

Will the FooProvider be instantiated once per request?

Answer 1

It should be

bind(Foo.class).toProvider(FooProvider.class).in(ServletScopes.REQUEST);

but otherwise this should work as expected.

Answer 2

No, FooProvider will be instantiated by Guice only once.

The scope applies to the binding, which means in your example that, if Foo is injected into another REQUEST-scoped object, Guice will call FooProvider.get() and will inject the returned Foo into that original object.

If you want the scope applied to FooProvider, then you would have to do something like that (NB: I haven't checked it but it should work):

bind(FooProvider.class).in(ServletScopes.REQUEST);
bind(Foo.class).toProvider(FooProvider.class).in(ServletScopes.REQUEST);