This change resolves a specific issue with processing
java.math.BigDecimal via ExtendedBeanInfo. BigDecimal has a particular
constellation of #setScale methods that, prior to this change, had the
potential to cause ExtendedBeanInfo to throw an IntrospectionException
depending on the order in which the methods were processed.
Because JDK 7 no longer returns deterministic results from
Class#getDeclaredMethods, it became a genuine possibility - indeed a
statistical certainty that the 'wrong' setScale method handling order
happens sooner or later. Typically one could observe this failure once
out of every four test runs.
This commit introduces deterministic method ordering of all discovered
non-void returning write methods in such a way that solves the problem
for BigDecimal as well as for any other class having a similar method
arrangement.
Also:
- Remove unnecessary cast
- Pass no method information to PropertyDescriptor superclasses when
invoking super(...). This ensures that any 'type mismatch'
IntrospectionExceptions are handled locally in ExtendedBeanInfo and
its Simple* PropertyDescriptor variants where we have full control.
Issue: SPR-10111, SPR-9702
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
Backport-Commit: 4a8be69099
Conflicts:
spring-beans/src/main/java/org/springframework/beans/ExtendedBeanInfoFactory.java
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
Backport-Issue: SPR-9929
Backport-Commit: 0709c033a0
