This commit also removes nullability from two common spots: ResolvableType.getType() and TargetSource.getTarget(), both of which are never effectively null with any regular implementation. For such scenarios, a non-null empty type/target is the cleaner contract.
Issue: SPR-15540
Beyond just formally declaring the current behavior, this revision actually enforces non-null behavior in selected signatures now, not tolerating null values anymore when not explicitly documented. It also changes some utility methods with historic null-in/null-out tolerance towards enforced non-null return values, making them a proper citizen in non-null assignments.
Some issues are left as to-do: in particular a thorough revision of spring-test, and a few tests with unclear failures (ignored as "TODO: NULLABLE") to be sorted out in a follow-up commit.
Issue: SPR-15540
Without this change the comparator thinks "/{foo}"
is more specific than "/{foo}.*". The minimal fix here
to address it is to copy what the AntPathMatcher
comparator does which is to consider '.*' as *not*
a usage of a wildcard. See PatternInfo#initCounters()
for the AntPathMatcher handling of this.
This change ensures the PathPattern comparator now produces
the expected result but suffix usage in general needs more
thought at some point.
Issue: SPR-15597
Restore matrix variable parsing code not resorting to the use of
WebUtils which brings Servlet API dependencies with it.
Instead the parsing logic is now exposed through HttpRequestPathHelper
which already contained the decoding logic and also the knowledge of
whether to decode the parsed variables or not.
Issue: SPR-15397
This commit adds the `LookupPath` class that contains the full
request path relative to the web context; the application can
get from it various information, including the file extension
and path parameters (if any).
Since that operation is done multiple times for each request, this
object is stored as an attribute at the `ServerWebExchange` level.
Issue: SPR-15397
With the new `ParsingPathMatcher` implementation, new patterns are now
allowed, such as `"/foo/{*bar}". The `"{*bar}"` segment will capture
everything until the end of the given path. Adding other elements after
that segment is illegal and will throw exceptions.
One can configure on a `PathMatchConfigurer` various options like
`useTrailingSlashMatch` and `useSuffixPatternMatch`; those options, when
enabled, will try to append suffixes like `".*"` and `"/"` to existing
path patterns. In case of a "capture the rest" pattern segment, those
options won't be honored.
This is why this commit ensures that an exception is thrown at the start
of the application if an illegal configuration is applied to the
`PathMatchConfigurer`.
Issue: SPR-15303, SPR-15558
When an exception happens while writing/flushing, the exception handling
for Servlet 3.1 based implementation will happen when
WriteListener#onError and AsyncListener#onError events are received
When reading more that once for a given request, the position/limit of
the buffer provided by Undertow should be reset in order to use the
full capacity of the buffer.
This commit fixes the implementation of
ExtractingResponseErrorHandler.hasError to allow for null values,
indicating an override of the behavior inherited from
DefaultResponseErrorHandler.
Issue: SPR-15544
This commit introduces ExtractingResponseErrorHandler: an alternative
ResponseErrorHandler that uses `HttpMessageConverter`s to convert HTTP
error responses to `RestClientException`.
Issue: SPR-15544
Simplify the internals of the DefaultCodecs implementation favoring
explicit fields per override vs a generic list of readers and writers
for overrides.
This commit introduces 2 new @Nullable and @NonNullApi
annotations that leverage JSR 305 (dormant but available via
Findbugs jsr305 dependency and already used by libraries
like OkHttp) meta-annotations to specify explicitly
null-safety of Spring Framework parameters and return values.
In order to avoid adding too much annotations, the
default is set at package level with @NonNullApi and
@Nullable annotations are added when needed at parameter or
return value level. These annotations are intended to be used
on Spring Framework itself but also by other Spring projects.
@Nullable annotations have been introduced based on Javadoc
and search of patterns like "return null;". It is expected that
nullability of Spring Framework API will be polished with
complementary commits.
In practice, this will make the whole Spring Framework API
null-safe for Kotlin projects (when KT-10942 will be fixed)
since Kotlin will be able to leverage these annotations to
know if a parameter or a return value is nullable or not. But
this is also useful for Java developers as well since IntelliJ
IDEA, for example, also understands these annotations to
generate warnings when unsafe nullable usages are detected.
Issue: SPR-15540
This commit introduces a new method in HttpRequest:
`String getMethodValue`, which returns the HTTP method as a String.
Furthermore, HttpRequest.getMethod() has been given a default
implementation using this String value in combination with
`HttpMethod.resolve`.
Issue: SPR-15545
HttpMessageConverter's are client and server and arguably shouldn't
contain a server-side concept such a response status.
The status field is recent, it was added to differentiate 400 vs 500
errors with Jackson 2.9+ but there is no need for it since the same
distinction is reflected in raising an HttpMessageNotReadableException
vs a general HttpMessageConversionException.
Issue: SPR-15516
Starting with removing a package cycle on the use of
ResponseStatusException in the codec package, this commit generally
refines codec exception handling.
The new [Encoding|Decoding]Exception mirror the existing
HttpMessageNot[Readable|Writable]Exception and are used similarly
especially to differentiate betwen 400 and 500 errors when parsing
server request body content.
The commit also aligns some of the exception handling of JSON and XML
on the WebFlux side with that on the Spring MVC side.
Issue: SPR-15516
