The intention of ExtendedBeanInfo, introduced with SPR-8079 in
v3.1.0.M2, was to support dependency injection against non-void
returning write methods. However, it also inadvertently introduced
support for injection against static setter methods.
When use of ExtendedBeanInfo was made optional with SPR-9723 in
v3.2.0.M2, ExtendedBeanInfo continued to support static write methods,
but its new BeanInfoFactory-based approach to testing whether or not
a given bean class contains candidate write methods was written in a
fashion exclusive of static methods, and this thereby introduced a
regression - a regression in an otherwise undocumented and unintended
feature, but a regression nevertheless.
The reporting of SPR-10115 proves that at least one user has come to
depend on this behavior allowing injection against static write
methods, and so this commit fixes the regression by ensuring that the
candidacy test includes standard and non-void setter methods having a
static modifier.
Issue: SPR-10115, SPR-9723, SPR-8079
Fix serialization warnings by applying @SuppressWarnings("serial")
when appropriate.
In certain cases and for unknown reasons, a correctly-placed
@SuppressWarnings("serial") annotation will fix the warning at the
javac level (i.e. the Gradle command-line), but will produce an
"unnecessary @SuppressWarnings" warning within Eclipse. In these
cases, a private static final serialVersionUID field has been added
with the default value of 1L.
In particular, avoiding synchronized Sets and Maps wherever possible (preferring a ConcurrentHashMap even instead of a synchronized Set) and specifying appropriate ConcurrentHashMap initial capacities (even if we end up choosing 16).
- Support external Javadoc links using Gradle's javadoc.options.links
- Fix all other Javadoc warnings, such as typos, references to
non-existent (or no longer existent) types and members, etc,
including changes related to the Quartz 2.0 upgrade (SPR-8275) and
adding the HTTP PATCH method (SPR-7985).
- Suppress all output for project-level `javadoc` tasks in order to
hide false-negative warnings about cross-module @see and @link
references (e.g. spring-core having a @see reference to spring-web).
Use the `--info` (-i) flag to gradle at any time to see project-level
javadoc warnings without running the entire `api` task. e.g.
`gradle :spring-core:javadoc -i`
- Favor root project level `api` task for detection of legitimate
Javadoc warnings. There are now zero Javadoc warnings across the
entirety of spring-framework. Goal: keep it that way.
- Remove all @link and @see references to types and members that exist
only in Servlet <= 2.5 and Hibernate <= 4.0, favoring 3.0+ and 4.0+
respectively. This is necessary because only one version of each of
these dependencies can be present on the global `api` javadoc task's
classpath. To that end, the `api` task classpath has now been
customized to ensure that the Servlet 3 API and Hibernate Core 4 jars
have precedence.
- SPR-8896 replaced our dependency on aspectjrt with a dependency on
aspectjweaver, which is fine from a POM point of view, but causes
a spurious warning to be emitted from the ant iajc task that it
"cannot find aspectjrt on the classpath" - even though aspectjweaver
is perfectly sufficient. In the name of keeping the console quiet, a
new `rt` configuration has been added, and aspectjrt added as a
dependency to it. In turn, configurations.rt.asPath is appended to
the iajc classpath during both compileJava and compileTestJava for
spring-aspects.
Issue: SPR-10078, SPR-8275, SPR-7985, SPR-8896
Previously, CachedIntrospectionResults had three modes of caching, with the intermediate mode relying on WeakReferences in the JDK PropertyDescriptor implementation. Since the JDK is actually using SoftReferences there these days, losing information in case of a GC run with tough memory constraints, we want to allow for hard references in PropertyDescriptor objects and therefore use a full WeakReference for the CachedIntrospectionResults object itself.
Issue: SPR-10028
This change revisits the implementation of ExtendedBeanInfo, simplifying
the overall approach while also ensuring that ExtendedBeanInfo is fully
isolated from the BeanInfo instance it wraps. This includes any existing
PropertyDescriptors in the wrapped BeanInfo - along with being copied
locally into ExtendedBeanInfo, each property descriptor is now also
wrapped with our own new "simple" PropertyDescriptor variants that
bypass the soft/weak reference management that goes on in both
java.beans.PropertyDescriptor and java.beans.IndexedPropertyDescriptor,
maintaining hard references to methods and bean classes instead. This
ensures that changes we make to property descriptors, e.g. adding write
methods, do not cause subtle conflicts during garbage collection (as was
reported and reproduced in SPR-9702).
Eliminating soft/weak reference management means that we must take extra
care to ensure that we do not cause ClassLoader leaks by maintaining
hard references to methods, and therefore transitively to the
ClassLoader in which the bean class was loaded. The forthcoming
SPR-10028 addresses this aspect.
See the updated ExtendedBeanInfo Javadoc for further details.
Issue: SPR-8079, SPR-8175, SPR-8347, SPR-8432, SPR-8491, SPR-8522,
SPR-8806, SPR-8931, SPR-8937, SPR-8949, SPR-9007, SPR-9059,
SPR-9414, SPR-9453, SPR-9542, SPR-9584, SPR-9677, SPR-9702,
SPR-9723, SPR-9943, SPR-9978, SPR-10028, SPR-10029
In particular, the specified object name may use a placeholder for its domain part now, allowing for several instances of the MBean to be registered against the same MBeanServer from different applications.
Issue: SPR-8244
Allow the body of 'arg-type' XML elements to be used as an alternative to
'match' attribute when defining a 'replace-method' in XML configuration.
This change has been introduced primarily to support the samples printed
in the Apress 'Pro Spring' book.
Issue: SPR-9812
Reverted change for @Bean methods that declare FactoryBean as their return type: The effects of trying to create the FactoryBean to find out about its implementation type are too far-reaching. It's better to recommend declaring a specific return type in the method signature if you want the container to specifically react to your implementation type.
Issue: SPR-9857
Includes a change for factory methods that declare their return type as FactoryBean: When asked for a specific type match (e.g. LoadTimeWeaverAware), we do check early singleton instances as well (reusing the instances that we create for getObjectType checks). This is necessary in order to make @Bean method introspection as capable as XML bean definition introspection, even in case of the @Bean method using a generic FactoryBean declaration for its return type (instead of the FactoryBean impl class).
Issue: SPR-9857
This change fixes further cases under JDK 6 in which setting a bridged
(e.g. String-returning) read method can conflict with an existing
corresponding bridge write method that accepts an Object parameter.
This appears to be a implementation difference between JDKs 6 and 7,
where the JDK 6 Introspector adds bridge methods and JDK 7 does not.
The solution here is to consistently null-out any existing write method
before setting the read method. We were doing this elsewhere in
ExtendedBeanInfo already, but these two changes make the approach
consistent throuhout.
Issue: SPR-8806
Autowired methods might have been skipped on subsequent creation of further bean instances due to the 'skip' flag set to false outside of the synchronized block, with another thread entering the block and setting the flag to true in the meantime.
Issue: SPR-9806
This commit refactors the BeanInfoFactory so that:
- supports() and getBeanInfo() are folded into one, so that getBeanInfo()
returns null if a given class is not supported.
- CachedIntrospectionResults now uses SpringFactoriesLoader
Prior to this change, CachedIntrospectionResults delegated to
ExtendedBeanInfo by default in order to inspect JavaBean
PropertyDescriptor information for bean classes.
Originally introduced with SPR-8079, ExtendedBeanInfo was designed to
go beyond the capabilities of the default JavaBeans Introspector in
order to support non-void returning setter methods, principally to
support use of builder-style APIs within Spring XML. This is a complex
affair, and the non-trivial logic in ExtendedBeanInfo has led to various
bugs including regressions for bean classes that do not declare
non-void returning setters.
This commit takes advantage of the new BeanInfoFactory mechanism
introduced in SPR-9677 to take ExtendedBeanInfo out of the default code
path for CachedIntrospectionResults. Now, the new
ExtendedBeanInfoFactory class will be detected and instantiated (per its
entry in the META-INF/spring.beanInfoFactories properties file shipped
with the spring-beans jar). ExtendedBeanInfoFactory#supports is invoked
for all bean classes in order to determine whether they are candidates
for ExtendedBeanInfo introspection, i.e. whether they declare non-void
returning setter methods.
If a class does not declare any such non-standard setter methods (the
99% case), then CachedIntrospectionResults will fall back to the
default JavaBeans Introspector. While efforts have been made to fix any
bugs with ExtendedBeanInfo, this change means that EBI will not pose
any future risk for bean classes that do not declare non-standard
setter methods, and also means greater efficiency in general.
Issue: SPR-9723, SPR-9677, SPR-8079
- Ensure that ExtendedBeanInfoTests succeeds when building under JDK 7
- Improve handling of read and write method registration where
generic interfaces are involved, per SPR-9453
- Add repro test for SPR-9702, in which EBI fails to register
an indexed read method under certain circumstances
Issue: SPR-9702, SPR-9414, SPR-9453
