Setter in Interfaces yes or no?

[ahoehma]

hello folks,

i have a interface-design-question ...

i have a document-service-interface:

public interface DocumentProvider {

FileContent getDocumentContent(Document aDocument);
...
void setDocumentHandlerRegistry(DocumentHandlerRegistry aRegistry);
}

Q: is it correct to insert the setter for the injected "service-bean" into the document-service-interface?

the document-service should use the document-handler-registry to "find" a document-handler
for the requested "document-type" (getDocumentContent) ... there are many different document-types and so
many differtn document-handlers.

Q: is registry a good name? document-handler-service could be a better name?!

Q: how should i initialize such a registry with spring ... i guess the xml should look a little bit complex at the end?!

any help will be welcome

regards
andreas

[Marten Deinum]

I think that a Service interface must only contain the the service methods. It can be quite well possible that 2 different implementations of those interfaces need different 'helper' methods. For instance one can need the setDocumentHandlerRegistry the other could simply look it up or create it's own.

Naming it depends on what it should do and what the conventions in your team are.

Initializing those service it can be as complex or not as you decide it to be. Especially with the new namespace support a lot can be done to cut down the size and complexity of configuration.

[karldmoore]

I would agree with Marten's comments. The collaborators of the service are an implementation detail so you don't really clutter the interface with it.

[debasishg]

Q: is it correct to insert the setter for the injected "service-bean" into the document-service-interface?

+1 with Marten - the setter is always part of the implementation.

Q: is registry a good name? document-handler-service could be a better name?!

Follow the domain terminology, what the domain users call it, aka The Ubiquitous Language ..

Cheers.
- Debasish