Provide runtime hints for the reflection of Spring WS

[sharanggupta]

This is a first step for #1329: it provides the runtime hints for the reflection that Spring WS performs itself, as suggested in #1329 (comment), so that an application does not have to collect them with the tracing agent.

What it registers

A WebServicesRuntimeHints registrar in META-INF/spring/aot.factories registers:

• The properties files of the default strategies of the WebServiceTemplate, the MessageDispatcher, the SoapMessageDispatcher and the MessageDispatcherServlet, and the constructors of the strategies they list, which the DefaultStrategiesHelper instantiates. The registrar reads the same properties files, so the hints follow any change to the defaults.
• The constructors of SoapMethodArgumentResolver and SoapHeaderElementMethodArgumentResolver, which the DefaultMethodEndpointAdapter instantiates by class name.
• The types of the optional XML libraries (DOM4J, JAXB, JDOM, StAX, XOM) that the DefaultMethodEndpointAdapter detects by class name, so that the detection works in a native image when the library is present.
• The constructor of the normalize-space XPath function of the JDK, which the JDK instantiates reflectively when the WS-Addressing support evaluates its expressions.

This covers what the configurations in the issue had to register by hand, except the internals of third-party libraries (the SAAJ resource bundle and the JAXB runtime classes), which belong to those libraries.

Endpoint methods

@PayloadRoot, @SoapAction and @Action are now meta-annotated with @Reflective, in the same way that @RequestMapping is for Spring MVC. During AOT processing, the methods of @Endpoint beans that they map are registered for invocation, so the endpoint mappings can find them and the MethodEndpoint can invoke them in a native image. The repeated forms work as well, as MergedAnnotations sees the annotations inside @PayloadRoots and @SoapActions.

The payload types of the endpoints, such as JAXB classes, still need their own hints, for instance with @RegisterReflectionForBinding. A ReflectiveProcessor that registers them from the @RequestPayload and @ResponsePayload signatures could follow, like ControllerMappingReflectiveProcessor does for @RequestBody, if you think that it belongs in Spring WS.

Testing

Developed test first: the tests failed against main (no hints are registered), and pass with the change.

• WebServicesRuntimeHintsTests loads the registrars from aot.factories, like the AOT engine does, and checks the hints with RuntimeHintsPredicates. For each default strategies file, it checks the resource and every strategy that the file lists.
• EndpointMappingAnnotationsRuntimeHintsTests runs the ReflectiveRuntimeHintsRegistrar on a sample endpoint, and checks that the mapped methods, including repeated annotations, are registered for invocation and that an unmapped method is not.
• ./gradlew :spring-ws-core:check :spring-ws-core:javadoc passes locally on JDK 25 (1047 tests in spring-ws-core, none skipped).

I did not build a native image to verify this end to end: that needs more memory than my machine has to spare. The hints match the configurations reported in the issue, which were verified in native images.

[sharanggupta]

I pushed a follow-up commit: the registrar now references all the hinted types by name. With the MessageDispatcherServlet.class literal, loading the registrar required the Servlet API, which is optional for spring-ws-core, so AOT processing would have failed for applications without it (client-only ones, for instance). The types of the optional XML libraries are now registered only when they are present.

[snicoll]

See #1329 (comment) - We don't have the bandwidth to review and support this going forward.