As of Spring Framework 5.3, `WebTestClient` can now be configured on top
of `MockMvc` for testing Spring MVC applications in a mock environment.
Prior to this commit, `WebTestClient` would be already configured for
WebFlux mock setups with `@AutoConfigureWebTestClient` or live servers
(for both MVC and WebFlux apps).
This commit enhances the `@AutoConfigureWebMvc` support so that a
`WebTestClient` instance is auto-configured if the spring-webflux
dependency is present on the classpath.
Closes gh-23067
Prior to this commit, some exceptions handled at the controller or
handler function level would:
* not bubble up to the Spring Boot error handling support
* not be tagged as part of the request metrics
This situation is inconsistent because in general, exceptions handled at
the controller level can be considered as expected behavior.
Also, depending on how the exception is handled, the request metrics
might not be tagged with the exception.
This will be reconsidered in gh-23795.
This commit prepares a transition to the new situation. Developers can
now opt-in and set the handled exception as a request attribute. This
well-known attribute will be later read by the metrics support and used
for tagging the request metrics with the exception provided.
This mechanism is automatically used by the error handling support in
Spring Boot.
Closes gh-24028
Refine the package restructure started in 91ccc23462 to help provide
a solid foundation for code snippets. This commit renames many of the
classes so that they no longer end in `Example`. It also removes some
of the inner types that were previously used. Many tag comments have
also been moved to ensure that `import` statements are available in
the docs.
Closes gh-25089
Restructure the packages in `spring-boot-docs` so that they mirror
the documentation sections. There are now three main packages:
`springbootfeatures`, `productionreadyfeatures` and `howto`. Each
of the main packages has a subpackage named after the section headings.
Example code now uses consistent `// tag::` names and imports are
applied using `[tag=*]` whenever possible.
Test snippets have been moved to `src/main/java` so that only a single
import attribute needs to be defined.
Closes gh-25089
