Thank you for that answer, however I may not use them as singletons, since they logically are not (well, I must keep track of several A's).
I tried to simplify the problem and removed all interfaces (because I thought they weren't useful in the problem presentation), but basically, I'm indeed managing interfaces, and not concrete classes, and therefore a proxy suits very fine. The "identity equality" comment was not to show that I require it, it meant more that I want to speak about a logically same instance, not two different instances created by Guice. Is the behaviour that you describe applicable to other instances than singletons, even with some additional code (without having to create the proxy myself though)? Any other suggestion? If no, I'll keep on going with the AssistedInject. Olivier 2009/4/17 Dhanji R. Prasanna <[email protected]> > It looks like you are talking about a circular relationship. If you mark > both as singletons and hide the dependency behind an interface, Guice will > automatically generate a proxy to hook this up for you. > You won't get identity equality (one will be a proxy), but the circular > relationship (1:1) will be maintained in effect. > > Dhanji. > > > On Sat, Apr 18, 2009 at 12:25 AM, Olivier <[email protected]> wrote: > >> >> Hello, >> >> I would like to create a 1 to 1 relationship between two components. >> Here is the "old-fashion" code that represent what I want to have. >> >> import static org.junit.Assert.*; >> import org.junit.Test; >> >> public class OneToOneRelationshipTest { >> static class A { >> final B b; >> A () { this.b = new B(this); } >> } >> static class B { >> final A a; >> B (A a) { this.a = a; } >> } >> >> @Test public void testOneToOneDependency() { >> A a = new A(); >> assertEquals(a, a.b.a); // check identity >> } >> } >> >> >> I've thought about using AssistedInject to transfer a factory of B to >> A: >> >> import static org.junit.Assert.*; >> import org.junit.Test; >> import com.google.inject.*; >> import com.google.inject.assistedinject.*; >> >> public class OneToOneRelationshipWithGuiceTest { >> static interface Factory { public B create(A a); } >> static class A { >> final B b; >> @Inject A (Factory f) { this.b = f.create(this); } >> } >> static class B { >> final A a; >> @Inject B (@Assisted A a) { this.a = a; } >> } >> static class Module extends AbstractModule { >> public void configure() { >> bind(A.class); >> >> bind(Factory.class).toProvider(FactoryProvider.newFactory >> (Factory.class, B.class)); >> } >> } >> >> @Test public void testOneToOneDependency() { >> A a = Guice.createInjector(new >> Module()).getInstance(A.class); >> assertEquals(a, a.b.a); // check identity >> } >> } >> >> >> >> However I'm wondering whether this is "too much" or not because my >> expectations are quite simple, but I feel like a more simple @Provides >> can help me. I just don't know how I could correctly modelize it, >> because I didn't see an example on the wiki. >> >> Can anyone help me getting rid of AssistedInject if possible? >> >> Olivier >> >> > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "google-guice" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/google-guice?hl=en -~----------~----~----~----~------~----~------~--~---
