In Spring Framework 7.0, we introduced support for using `Optional`
with the null-safe and Elvis operators in SpEL expressions; however,
such expressions were previously not compilable.
To address that, this commit introduces a new
insertOptionalUnwrapIfNecessary() method in CodeFlow which effectively
inserts byte code instructions for `myOptional.orElse(null)`, and the
Elvis, Indexer, MethodReference, and PropertyOrFieldReference
implementations have been modified to track the need to unwrap an
`Optional` in compiled mode and delegate to
insertOptionalUnwrapIfNecessary() accordingly.
See gh-20433
See gh-36331
Closes gh-36330
Although this commit also changes the visibility of some test methods
to package-private, the remainder of that task will be addressed in
conjunction with gh-36496.
Closes gh-36495
Since the Spring Framework uses American English spelling, this commit
updates Javadoc and the reference manual to ensure consistency in that
regard. However, there are two exceptions to this rule that arise due
to their use within a technical context.
- We use "cancelled/cancelling" instead of "canceled/canceling" in
numerous places (including error messages).
- We use "implementor" instead of "implementer".
Closes gh-36470
This commit introduces two tests to verify the status quo.
- mapAccessThroughIndexerForNonexistentKey(): demonstrates that map
access via the built-in support in the Indexer returns `null` for a
nonexistent key.
- nullAwareMapAccessor(): demonstrates that users can implement and
register a custom extension of MapAccessor which reports that it can
read any map (ignoring whether the map actually contains an entry for
the given key) and returns `null` for a nonexistent key.
See gh-35534
Prior to this commit, the MapAccessor for SpEL resided in the
org.springframework.context.expression package in the spring-context
module; however, it arguably should reside in the spring-expression
module so that it can be used whenever SpEL is used (without requiring
spring-context).
This commit therefore officially deprecates the MapAccessor in
spring-context for removal in favor of a new copy of the implementation
in the org.springframework.expression.spel.support package in the
spring-expression module.
Closes gh-35537
We have had an ObjectToOptionalConverter since Spring Framework 4.1;
however, prior to this commit we did not have a standard Converter for
the inverse (Optional to Object).
To address that, this commit introduces an OptionalToObjectConverter
that unwraps an Optional, using the ConversionService to convert the
object contained in the Optional (potentially null) to the target type.
This allows for conversions such as the following.
- Optional.empty() -> null
- Optional.of(42) with Integer target -> 42
- Optional.of(42) with String target -> "42"
- Optional.of(42) with Optional<String> target -> Optional.of("42")
The OptionalToObjectConverter is also registered by default in
DefaultConversionService, alongside the existing
ObjectToOptionalConverter.
See gh-20433
Closes gh-34544
This commit removes the BDDMockito Checkstyle rule, since it did not
actually enforce the use of BDDMockito.
This commit also updates static imports to use Mockito instead of
BDDMockito where appropriate (automated via the Eclipse IDE Organize
Imports clean-up task).
Closes gh-34616
This commit introduces null-safe support for java.util.Optional in the
following SpEL operators:
- PropertyOrFieldReference
- MethodReference
- Indexer
- Projection
- Selection
- Elvis
Specifically, when a null-safe operator is applied to an empty
`Optional`, it will be treated as if the `Optional` were `null`, and
the subsequent operation will evaluate to `null`. However, if a
null-safe operator is applied to a non-empty `Optional`, the subsequent
operation will be applied to the object contained in the `Optional`,
thereby effectively unwrapping the `Optional`.
For example, if `user` is of type `Optional<User>`, the expression
`user?.name` will evaluate to `null` if `user` is either `null` or an
empty `Optional` and will otherwise evaluate to the `name` of the
`user`, effectively `user.get().getName()` for property access.
Note, however, that invocations of methods defined in the `Optional`
API are still supported on an empty `Optional`. For example, if `name`
is of type `Optional<String>`, the expression `name?.orElse('Unknown')`
will evaluate to "Unknown" if `name` is an empty `Optional` and will
otherwise evaluate to the `String` contained in the `Optional` if
`name` is a non-empty `Optional`, effectively `name.get()`.
Closes gh-20433
Prior to this commit, if an appropriate Converter was registered with
the ConversionService that converts from a POJO to an array and that
ConversionService was registered with the Spring Expression Language
(SpEL) TypeConverter, an attempt to invoke a varargs method in a SpEL
expression with such a POJO would fail because the ConversionService
was not used to convert the POJO to an array suitable for the varargs
method invocation.
This commit revises the implementations of convertArguments(...) and
convertAllMethodHandleArguments(...) in ReflectionHelper to support
such use cases.
Closes gh-34371
This commit updates the whole Spring Framework codebase to use JSpecify
annotations instead of Spring null-safety annotations with JSR 305
semantics.
JSpecify provides signficant enhancements such as properly defined
specifications, a canonical dependency with no split-package issue,
better tooling, better Kotlin integration and the capability to specify
generic type, array and varargs element null-safety. Generic type
null-safety is not defined by this commit yet and will be specified
later.
A key difference is that Spring null-safety annotations, following
JSR 305 semantics, apply to fields, parameters and return values,
while JSpecify annotations apply to type usages. That's why this
commit moves nullability annotations closer to the type for fields
and return values.
See gh-28797
Prior to this commit, if a MethodHandle was registered as a custom
function in the Spring Expression Language (SpEL) for a static method
that accepted only a variable argument list (for example,
`static String func(String... args)`), attempting to invoke the
registered function within a SpEL expression resulted in a
ClassCastException because the varargs array was unnecessarily wrapped
in an Object[].
This commit modifies the logic in FunctionReference's internal
executeFunctionViaMethodHandle() method to address that.
Closes gh-34109
Sam Brannen
Yanming Zhou
Tran Ngoc Nhan
rstoyanchev
Sébastien Deleuze
Spring Builds
Sébastien Deleuze
Juergen Hoeller
Brian Clozel