Inject a Class with GIN

Question

Is there a way to inject a class type Class<T> in gin? I can't seem to get it working, for example:

class GenericFoo<T> {

  private final Class<T> klass;

  @Inject
  public GenericFoo(Class<T> klass) {
    this.klass = klass;
  }
}

class Bar { }

with an instance injected somewhere:

..
@Inject
GenericFoo<Bar> instance;
..

and a GinModule containing something along the lines of:

bind(new TypeLiteral<Class<Bar>>() {}).to(Bar.class);

Thanks

score 3 · Answer 1 · answered Aug 17 '11 at 13:40

3

It's not possible. Reflection is forbidden on the client side, so GIN for dependency injection is using deffered binding. It means that during the compilation, GWT generates target implementations which are unknow in your case.

answered Aug 17 '11 at 13:40

kospiotr

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I'm sorry, I think you misunderstood me, made an edit to clarify. I don't need reflection, just want to bind Class to Foo.getClass(). – ryan Aug 17 '11 at 15:12

score 3 · Answer 2 · answered Aug 22 '11 at 20:42

If this were regular Guice (as opposed to Gin), you could do:

bind(new TypeLiteral<Class<Bar>>(){}).toInstance(Bar.class);

But Gin doesn't support .toInstance(...) bindings. Instead, you should be able to use a Provider or an @Provides method, like:

@Provides
Class<Bar> providesBarClass() {
  return Bar.class;
}

Inject a Class with GIN

2 Answers2

Linked