Commit 3295289e17 fixed a number issues with placeholder resolution in
PropertySourcesPlaceholderConfigurer. However, in doing so, it replaced
a raw PropertySource with a CompositePropertySource which implements
EnumerablePropertySource.
Consequently, all property sources registered in the Environment must
now implement EnumerablePropertySource (which is not an actual
requirement). Otherwise, invocations of getPropertyNames() on the
CompositePropertySource result in an IllegalStateException, and that is
a breaking change which resulted in numerous build failures within the
Spring portfolio.
To address that regression, this commit introduces a private
ConfigurableEnvironmentPropertySource in
PropertySourcesPlaceholderConfigurer which is a "raw" PropertySource
that delegates directly to the PropertySources in a
ConfigurableEnvironment.
This commit also extracts the raw PropertySource for direct Environment
delegation into a new FallbackEnvironmentPropertySource.
See gh-17385
Closes gh-34861
Currently, the placeholder resolution algorithm in
PropertySourcesPlaceholderConfigurer fails in several scenarios, and
the root cause for this category of failures has actually existed since
PropertySourcesPlaceholderConfigurer was introduced in Spring Framework
3.1.
Specifically, PropertySourcesPlaceholderConfigurer creates its own
PropertySourcesPropertyResolver that indirectly delegates to another
"nested" PropertySourcesPropertyResolver to interact with
PropertySources from the Environment, which results in double
placeholder parsing and resolution attempts, and that behavior leads to
a whole category of bugs.
For example, #27947 was addressed in Spring Framework 5.3.16, and due
to #34315 and #34326 we have recently realized that additional bugs
exist with placeholder resolution: nested placeholder resolution can
fail when escape characters are used, and it is currently impossible
to disable the escape character support for nested resolution.
To address this category of bugs, we no longer indirectly use or
directly create a "nested" PropertySourcesPropertyResolver in
PropertySourcesPlaceholderConfigurer. Instead, properties from property
sources from the Environment are now accessed directly without
duplicate/nested placeholder resolution.
See gh-27947
See gh-34326
See gh-34862
Closes gh-34861
Historically, @Configuration classes that did not declare @Bean
methods were allowed to be abstract. However, the changes made in
76a6b9ea79 introduced a regression that prevents such classes from
being abstract, resulting in a BeanInstantiationException. This change
in behavior is caused by the fact that such a @Configuration class is
no longer replaced by a concrete subclass created dynamically by CGLIB.
This commit restores support for abstract @Configuration classes
without @Bean methods by modifying the "no enhancement required" check
in ConfigurationClassParser.
See gh-34486
Closes gh-34663
This commit removes the use of RepeatableContainers.of() in
AnnotationJmxAttributeSource since that is unnecessary when using the
MergedAnnotations API with @Repeatable annotations such as
@ManagedOperationParameter and @ManagedNotification.
Closes gh-34606
This commit introduces a new BeanRegistrarDsl that supersedes
BeanDefinitionDsl which is now deprecated.
See BeanRegistrarDslConfigurationTests for a concrete example.
See gh-18353
This commit introduces a new BeanRegistrar interface that can be
implemented to register beans programmatically in a concise and
flexible way.
Those bean registrar implementations are typically imported with
an `@Import` annotation on `@Configuration` classes.
See BeanRegistrarConfigurationTests for a concrete example.
See gh-18353
Prior to this commit, `SimpleKey` would be used in Spring Framework's
caching support and its `hashCode` value would be used to efficiently
store this key in data structures.
While the current hashcode strategy works, the resulting values don't
spread well enough when input keys are sequential (which is often the
case). This can have negative performance impacts, depending on the
data structures used by the cache implementation.
This commit improves the `hashCode` function with a mixer to better
spread the hash values. This is using the mixer function from the
MurMur3 hash algorithm.
Closes gh-34483
