Before this commit, the CachedIntrospectionResults was hard-coded to
create ExtendedBeanInfos for bean classes. The ExtendedBeanInfo support
the JavaBeans property contract only.
This commit introduces the BeanInfoFactory, a strategy for creating
BeanInfos. Through this strategy, it is possible to support
beans that do not necessarily implement the JavaBeans contract (i.e.
have a different getter or setter style).
BeanInfoFactories are are instantiated by the
CachedIntrospectionResults, which looks for
'META-INF/spring.beanInfoFactories' files on the class path. These files
contain one or more BeanInfoFactory class names. When a BeanInfo is to
be created, the CachedIntrospectionResults will iterate through the
factories, asking it to create a BeanInfo for the given bean class. If
none of the factories support it, an ExtendedBeanInfo is created as a
default.
This commit also contains a change to Property, allowing BeanWrapperImpl
to specify the property name at construction time (as opposed to using
Property#resolveName(), which supports the JavaBeans contract only).
Issue: SPR-9677
CGLIB 3 has been released in order to depend on ASM 4, which Spring now
depends on internally (see previous commit).
This commit eliminates spring-beans' optional dependency on cglib-nodep
v2.2 and instead repackages net.sf.cglib => org.springframework.cglib
much in the same way we have historically done with ASM.
This change is beneficial to users in several ways:
- Eliminates the need to manually add CGLIB to the application
classpath; especially important for the growing number of
@Configuration class users. Java-based configuration functionality,
along with proxy-target-class and method injection features now
work 'out of the box' in Spring 3.2.
- Eliminates the possibility of conflicts with other libraries that
may dependend on differing versions of CGLIB, e.g. Hibernate
3.3.1.ga and its dependency on CGLIB 2.1.3 would easily cause a
conflict if the application were depending on CGLIB 3 for
Spring-related purposes.
- Picks up CGLIB 3's changes to support ASM 4, meaning that CGLIB is
that much less likely to work well in a Java 7 environment due to
ASM 4's support for transforming classes with invokedynamic
bytecode instructions.
On CGLIB and ASM:
CGLIB's own dependency on ASM is also transformed along the way to
depend on Spring's repackaged org.springframework.asm, primarily to
eliminate unnecessary duplication of ASM classfiles in spring-core and
in the process save around 100K in the final spring-core JAR file size.
It is coincidental that spring-core and CGLIB currently depend on the
exact same version of ASM (4.0), but it is also unlikely to change any
time soon. If this change does occur and versions of ASM drift, then
the size optimization mentioned above will have to be abandoned. This
would have no compatibility impact, however, so this is a reasonable
solution now and for the forseeable future.
On a mysterious NoClassDefFoundError:
During the upgrade to CGLIB 3.0, Spring test cases began failing due to
NoClassDefFoundErrors being thrown from CGLIB's DebuggingClassWriter
regarding its use of asm-util's TraceClassVisitor type. previous
versions of cglib-nodep, particularly 2.2, did not cause this behavior,
even though cglib-nodep has never actually repackaged and bundled
asm-util classes. The reason for these NoClassDefFoundErrors occurring
now is still not fully understood, but appears to be due to subtle JVM
bytecode preverification rules. The hypothesis is that due to minor
changes in DebuggingClassWriter such as additional casts, access to
instance variables declared in the superclass, and indeed a change in
the superclass hierarchy, preverification may be kicking in on the
toByteArray method body, at which point the reference to the missing
TraceClassVisitor type is noticed and the NCDFE is thrown. For this
reason, a dummy implementation of TraceClassVisitor has been added to
spring-core in the org.springframework.asm.util package. This class
simply ensures that Spring's own tests never result in the NCDFE
described above, and more importantly that Spring's users never
encounter the same.
Other changes include:
- rename package-private Cglib2AopProxy => CglibAopProxy
- eliminate all 'cglibAvailable' checks, warnings and errors
- eliminate all 'CGLIB2' language in favor of 'CGLIB'
- eliminate all mention in reference and java docs of needing to add
cglib(-nodep) to one's application classpath
Issue: SPR-9669
Currently, if a factory method is parameterized and the corresponding
variable types are declared on the method itself instead of on the
enclosing class or interface, Spring always predicts the return type to
be Object, even if the return type can be explicitly inferred from the
method signature and supplied arguments (which are available in the bean
definition).
This commit introduces a new resolveParameterizedReturnType() method in
GenericTypeResolver that attempts to infer the concrete type for the
generic return type of a given parameterized method, falling back to the
standard return type if necessary. Furthermore,
AbstractAutowireCapableBeanFactory now delegates to
resolveParameterizedReturnType() when predicting the return type for
factory methods.
resolveParameterizedReturnType() is capable of inferring the concrete
type for return type T for method signatures similar to the following.
Such methods may potentially be static. Also, the formal argument list
for such methods is not limited to a single argument.
- public <T> T foo(Class<T> clazz)
- public <T> T foo(Object obj, Class<T> clazz)
- public <V, T> T foo(V obj, Class<T> clazz)
- public <T> T foo(T obj)
Issue: SPR-9493
The failure of the conversion service is not fatal, but the check that
was in there (line 248) was inadequate to detect the cases that could
already be handled by the default property editors. This code path
was also not tested anywhere in spring-beans tests until now.
Prior to this change, by-type lookups using DLBF#getBeanNamesForType
required traversal of all bean definitions within the bean factory
in order to inspect their bean class for assignability to the target
type. These operations are comparatively expensive and when there are a
large number of beans registered within the container coupled with a
large number of by-type lookups at runtime, the performance impact can
be severe. The test introduced here demonstrates such a scenario clearly.
This performance problem is likely to manifest in large Spring-based
applications using non-singleton beans, particularly request-scoped
beans that may be created and wired many thousands of times per second.
This commit introduces a simple ConcurrentHashMap-based caching strategy
for by-type lookups; container-wide assignability checks happen only
once on the first by-type lookup and are afterwards cached by type
with the values in the map being an array of all bean names assignable
to that type. This means that at runtime when creating and autowiring
non-singleton beans, the cost of by-type lookups is reduced to that of
ConcurrentHashMap#get.
Issue: SPR-6870
Previously, the <value> subelement of a map <entry> allowed one to
specify the type of a specific map entry value. This patch allows a
value-type attribute as well, such that instead of the following
syntax
<entry key="x-message-ttl">
<value type="java.lang.Long">100</value>
</entry>
<entry key="x-ha-policy" value="all" />
one can now use the more concise form
<entry key="x-message-ttl" value="100" value-type="java.lang.Long"/>
<entry key="x-ha-policy" value="all"/>
The new value-type attribute may be used at the <map> level as well,
indicating that all elements are of the same type.
Appropriate tests have been added exercising value-type at the <map> and
<entry> levels.
Issue: SPR-9249
* 3.1.x: (61 commits)
Compensate for changes in JDK 7 Introspector
Avoid 'type mismatch' errors in ExtendedBeanInfo
Polish ExtendedBeanInfo and tests
Infer AnnotationAttributes method return types
Minor fix in MVC reference doc chapter
Hibernate 4.1 etc
TypeDescriptor equals implementation accepts annotations in any order
"setBasenames" uses varargs now (for programmatic setup; SPR-9106)
@ActiveProfiles mechanism works with @ImportResource as well (SPR-8992
polishing
clarified Resource's "getFilename" method to consistently return null
substituteNamedParameters detects and unwraps SqlParameterValue object
Replace spaces with tabs
Consider security in ClassUtils#getMostSpecificMethod
Adding null check for username being null.
Improvements for registering custom SQL exception translators in app c
SPR-7680 Adding QueryTimeoutException to the DataAccessException hiera
Minor polish in WebMvcConfigurationSupport
Detect overridden boolean getters in ExtendedBeanInfo
Polish ExtendedBeanInfoTests
...
Each of these tests began failing during the Gradle build porting
process. None seem severe, many are likely due to classpath issues.
In the case of TestNG support, this needs to be added to the Gradle
build in order to execute these tests. See SPR-8116.txt
This renaming more intuitively expresses the relationship between
subprojects and the JAR artifacts they produce.
Tracking history across these renames is possible, but it requires
use of the --follow flag to `git log`, for example
$ git log spring-aop/src/main/java/org/springframework/aop/Advisor.java
will show history up until the renaming event, where
$ git log --follow spring-aop/src/main/java/org/springframework/aop/Advisor.java
will show history for all changes to the file, before and after the
renaming.
See http://chrisbeams.com/git-diff-across-renamed-directories
