Previously, an error would occur when a user contributed a
`ThemeResolver` or `FlashMapManager` bean because those beans would
would not properly override the default beans provided by Spring
Framework. This commit adds conditional auto-configuration of these
bean types, preferring user-provided beans and falling back to
Framework-provided defaults.
Fixes gh-24207
This commit changes the default value of bootstrap-mode to "default"
rather than "deferred" so that the JPA infrastructure starts in the
main thread rather than asynchronously.
Closes gh-24249
Web MVC and WebFlux look up by name the Locale(Context)Resolver beans
that they use. Previously, the auto-configured resolvers for MVC and
WebFlux would back off when any bean of the required type was defined,
irrespective of its name. If the name of the user's bean didn't match
the name used by MVC and WebFlux to find the custom resolver, the
custom resolver would be ignored and MVC and WebFlux would use their
defaults. There was no indication of this happening in the condition
evaluation report as all it would show is that the auto-configured
resolver had backed off in favour of the custom resolver. It wouldn't
show anything to explain why the custom resolver had not been used.
This commit updates the auto-configured resolvers to be conditional
on a missing bean of the name required by MVC and WebFlux. If the
user then defines a custom resolver with a different name, the
condition evaluation report will show that the auto-configured
resolver remained as the bean name didn't match.
Fixes gh-24209
Prior to this commit, packaging a Spring Boot application as a container
image with Cloud Native Buildpacks could result in unwanted browser
caching behavior, with "Last-Modified" HTTP response headers pointing to
dates in the far past.
This is due to CNB resetting the last-modified date metadata for static
files (for build reproducibility and container layer caching) and Spring
static resource handling relying on that information when serving static
resources.
This commit introduces a new configuration property
`spring.web.resources.cache.use-last-modified` that can be used to
disable this behavior in Spring if the application is meant to run as a
container image built by CNB.
The default value for this property remains `true` since this remains
the default value in Spring Framework and using that information in
other deployment models is a perfectly valid use case.
Fixes gh-24099
