Allow schema and validation event handler customization in JAXBContextFactory

[virtual-machinist]

The default JAXB behavior is to silently ignore errors caused by input being incorrect, so eg. an Integer field will remain null for an input foo. This isn't always preferred, but to fix that a ValidationEventHandler implementation must be assigned to the created Unmarshaller. It may be as simple as event -> false.

For a more complex validation scenario a Schema may be needed.

However at the moment there is no way to set up either of those in Marshaller and Unmarshaller instances created in JAXB and SOAP encoders/decoders.

The PR addresses this problem by adding the customization options for feign.jaxb.JAXBContextFactory in jaxb and jaxb-jakarta modules. A customized JAXBContextFactory may then be used to address the original issue in #1479 .

[velo]

So, this is piling more and more functionality/code into feign to allow fine tuning... wonder if it would be possible to turn this into an interface that allows user to do whatever they to JAXBContext and pass it to feign in a more transparent way..

[virtual-machinist]

JAXBContextFactory is IMO a misnomer, as it's mainly used to create Marshaller and Unmarshaller instances - things that actually do the serialization and deserialization. The contexts are also created, but are cached per class, and usually an application can have a single context for all supported classes if there's no package/namespace collisions. But JAXBContext once created isn't very customizable by itself and I don't see a way to achieve the needed fine-tuning unless we do some subclassing hackery and delegate to the real thing from Glassfish or your favorite JAXB provider. This is IMO much more fragile than the solution proposed here. That said we can actually create some sort of MarshallerCustomizer / UnmarshallerCustomizer interface that does the needed post-processing. We may even wrap the already implemented property setters as instances of such customizers and execute them in sequential order like done for request interceptors. How's that sound?

…

On Tue, Jun 20, 2023, 00:02 Marvin Froeder ***@***.***> wrote: ***@***.**** commented on this pull request. ------------------------------ In jaxb-jakarta/src/main/java/feign/jaxb/JAXBContextFactory.java <#2084 (comment)>: > @@ -51,6 +78,10 @@ public Unmarshaller createUnmarshaller(Class<?> clazz) throws JAXBException { public Marshaller createMarshaller(Class<?> clazz) throws JAXBException { Marshaller marshaller = getContext(clazz).createMarshaller(); setMarshallerProperties(marshaller); + if (marshallerEventHandler != null) { So, this is piling more and more functionality/code into feign to allow fine tuning... wonder if it would be possible to turn this into an interface that allows user to do whatever they to JAXBContext and pass it to feign in a more transparent way.. — Reply to this email directly, view it on GitHub <#2084 (review)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAOF63JBEN7UXCHZVDZ4EOTXMC46BANCNFSM6AAAAAAZGNVESQ> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[velo]

How's that sound?

sounds great, would avoid all ifs inside feign, if you keen to do it, I would like to see it