Allows a convenient mechanism for contributing a PropertySource to the
enclosing Spring Environment. See @PropertySource Javadoc for
complete details and PropertySourceAnnotationTests for examples.
Issue: SPR-8314
Users may now call #setRequiredProperties(String...) against the
Environment (via its ConfigurablePropertyResolver interface) in order
to indicate which properties must be present.
Environment#validateRequiredProperties() is invoked by
AbstractApplicationContext during the refresh() lifecycle to perform
the actual check and a MissingRequiredPropertiesException is thrown
if the precondition is not satisfied.
Issue: SPR-8323
Declaring @Bean methods as 'static' is now permitted, whereas previously
it raised an exception at @Configuration class validation time.
A static @Bean method can be called by the container without requiring
the instantiation of its declaring @Configuration class. This is
particularly useful when dealing with BeanFactoryPostProcessor beans,
as they can interfere with the standard post-processing lifecycle
necessary to handle @Autowired, @Inject, @Value, @PostConstruct and
other annotations.
static @Bean methods cannot recieve CGLIB enhancement for scoping and
AOP concerns. This is acceptable in BFPP cases as they rarely if ever
need it, and should not in typical cases ever be called by another
@Bean method. Once invoked by the container, the resulting bean will
be cached as usual, but multiple invocations of the static @Bean method
will result in creation of multiple instances of the bean.
static @Bean methods may not, for obvious reasons, refer to normal
instance @Bean methods, but again this is not likely a concern for BFPP
types. In the rare case that they do need a bean reference, parameter
injection into the static @Bean method is technically an option, but
should be avoided as it will potentially cause premature instantiation
of more beans that the user may have intended.
Note particularly that a WARN-level log message is now issued for any
non-static @Bean method with a return type assignable to BFPP. This
serves as a strong recommendation to users that they always mark BFPP
@Bean methods as static.
See @Bean Javadoc for complete details.
Issue: SPR-8257, SPR-8269
Prior to this change, @ComponentScan annotations were only processed at
the first level of depth. Now, the set of bean definitions resulting
from each declaration of @ComponentScan is checked for configuration
classes that declare @ComponentScan, and recursion is performed as
necessary.
Cycles between @ComponentScan declarations are detected as well. See
CircularComponentScanException.
Issue: SPR-8307
Introduce @EnableAsync#order
AsyncAnnotationBeanPostProcessor's 'order' property is now mutable;
@EnableAsync's 'order()' attribute allows for setting it, but must
have a default value, thus uses the new Ordered#NOT_ORDERED
constant - a reserved negative number very unlikely to be otherwise
used that may be interpreted as 'not ordered', useful in annotation
defaulting scenarios where null is not an option.
Introduce first working cut of AsyncConfiguration
Remove AsyncCapability
This change is in support of certain polymorphism cases in
@Configuration class inheritance hierarchies. Consider the following
scenario:
@Configuration
public abstract class AbstractConfig {
public abstract Object bean();
}
@Configuration
public class ConcreteConfig {
@Override
@Bean
public BeanPostProcessor bean() { ... }
}
ConcreteConfig overrides AbstractConfig's #bean() method with a
covariant return type, in this case returning an object of type
BeanPostProcessor. It is critically important that the container
is able to detect the return type of ConcreteConfig#bean() in order
to instantiate the BPP at the right point in the lifecycle.
Prior to this change, the container could not do this.
AbstractAutowireCapableBeanFactory#getTypeForFactoryMethod called
ReflectionUtils#getAllDeclaredMethods, which returned Method objects
for both the Object and BeanPostProcessor signatures of the #bean()
method. This confused the implementation sufficiently as not to
choose a type for the factory method at all. This means that the
BPP never gets detected as a BPP.
The new method being introduced here, #getUniqueDeclaredMethods, takes
covariant return types into account, and filters out duplicates,
favoring the most specific / narrow return type.
Additionally, it filters out any CGLIB 'rewritten' methods, which
is important in the case of @Configuration classes, which are
enhanced by CGLIB. See the implementation for further details.
Consolidating internal bean name and aspect class name constats within
AnnotationConfigUtils to allow access from both the context.config
and context.annotation packages without creating a relationship between
the two of them (they are unrelated leaf nodes in the packaging
currently).
The .transaction module does not have a similar utils class and already
has a relationship from transaction.config -> transaction.annotation,
so placing the constants in .annotation.TransactionManagementCapability
to be referenced by .config.AnnotationDrivenBeanDefinitionParser
Allows @Enable* a layer of indirection for deciding which @Configuration
class(es) to @Import.
The @Import annotation may now accept @Configuration class literals
and/or ImportSelector class literals.
@Configuration classes may implement ImportAware in order to be injected
with the AnnotationMetadata of their @Import'ing class.
Includes the introduction of a new PriorityOrdered
ImportAwareBeanPostProcessor that handles injection of the
importing class metadata.
Includes the introduction of AnnotationUtils#findAllAnnotationAttributes
to support iterating through all annotations declared on a given type
and interrogating each for the presence of a meta-annotation. See tests
for details.
Feature-related support such as @Feature, @FeatureConfiguration,
and FeatureSpecification types will be replaced by framework-provided
@Configuration classes and convenience annotations such as
@ComponentScan (already exists), @EnableAsync, @EnableScheduling,
@EnableTransactionManagement and others.
Issue: SPR-8012,SPR-8034,SPR-8039,SPR-8188,SPR-8206,SPR-8223,
SPR-8225,SPR-8226,SPR-8227
The overloading necessary to preserve the new signature as well as
the old causes ambiguities leading to deprecation warnings in some
caller scenarios.
Previously errors were being raised when trying to inject @Value
annotated paramaters such as:
@Feature
public FeatureSpec feature(@Value("#{environment['foo']}") String foo) {
return new FeatureSpec(foo);
}
This is not so much because dependency resolution of @Value-annotated
types was failing, but rather because the 'early bean reference'
proxying mechanism was throwing an exception if any final type was
detected as a parameter. This is of course because final types are
non-subclassable by CGLIB. On review, however, it's obvious that
certain final types must be allowed for injection. @Value injection
is an obvious one, but the rarer case of a Spring bean of type String
or int is another.
The explicit guard against final types as parameters to @Feature methods
has been removed. Final types are still checked for, however, and if
found, no proxing is attempted. The dependency is immediately resolved
against the current BeanFactory and injected into the @Feature method.
This means that @Value injection, @Qualifier injection, etc all work
as expected, but does mean that premature bean instantiation may occur
if a user unwittingly injects non-String, non-primitive final bean types
as @Feature method parameters.
Issue: SPR-7974
CGLIB-enhanced @Configuration subclasses now implement DisposableBean
such that Enhancer.registerStaticCallbacks(subclass, null) is invoked
on container shutdown. This ensures that garbage collection can work
properly and avoids memory consumption issues for applications that
create and destroy many application contexts within the same JVM.
Issue: SPR-7901
Chris Beams
Costin Leau
Micha Kiener
Sam Brannen
Rossen Stoyanchev