Align DispatcherServlet defaults for Java and XML

[sdeleuze]

In order to improve GraalVM compatibility (by requiring less reflection configuration) and for the sake of consistency, we should probably register these 4 missing beans in WebMvcConfigurationSupport:

• org.springframework.web.servlet.i18n.AcceptHeaderLocaleResolver
• org.springframework.web.servlet.theme.FixedThemeResolver
• org.springframework.web.servlet.support.SessionFlashMapManager
• org.springframework.web.servlet.view.DefaultRequestToViewNameTranslator

We should also make sure the same is done on XML side and should then make DispatcherServlet.properties parsing lazy as most use case will not use it.

Finally, we should check that no Spring Boot configuration update is needed.

[mdeinum]

I have a branch that includes these additional beans in both Java and XML configuration. I can provide a pull request if you like?

I was still pondering on the lazy loading. This kind of mechanism is used on other places as well, would it make sense to extract to loading of default strategies to a standalone class, for reuse in other places as well?

[sdeleuze]

@mdeinum Sure thanks, feel free to create a PR for that. I already implemented lazy loading via e2944c3.

[sdeleuze]

After a deeper look I think there is a 4th bean to add: org.springframework.web.servlet.view.DefaultRequestToViewNameTranslator.