Question

I trying to build a simple lib for persistence with guice persist and some other things.

I already have a AbstractDao<T>, that I can easily extend and bind the concrete implementation like a boss.

But, I want a kind of GenericDao, like this:

public abstract class GenericDao<T extends Bean> {


@Inject
private Provider<EntityManager> emp;

protected EntityManager em() {
    return emp.get();
}

public AbstractDao() {
}

protected abstract Class<T> clazz();
// ....

And if I will have just the CRUD (implemented in abstract dao) in for some bean, I want to inject GenericDao<SomeBean> like a boss.

So, I started to try some hacks, and get the following:

public abstract class AbstractPersistentModule extends AbstractModule {

    protected <T extends Bean> LinkedBindingBuilder<T> bindGenericDao(final Class<T> clazz) {
       return bind(
               new TypeLiteral<GenericDao<T>>(){}
       )./* what the hell can I do here? */;
    }
}

If I can make it work, I’ll be able to do a simple:

bindGenericDao(Pessoa.class);

Someone know a way to do that?

Answer 1

See this post for a working implementation.