AnnotationConfigApplicationContext and
AnnotationConfigWebApplicationContext both expose #register and #scan
methods as of the completion of SPR-8320. This change introduces a new
interface that declares each of these methods and refactors ACAC and
ACWAC to implement it.
Beyond information value, this is useful for implementors of the
ApplicationContextInitializer interface, in that users may create an ACI
that works consistently across ACAC and ACWAC for standalone (e.g.
testing, batch) or web (e.g. production) use.
Issue: SPR-8365,SPR-8320
Primarily for use in conjunction with ApplicationContextInitializer,
these new #scan and #register methods mirror those in
AnnotationConfigApplicationContext. #setConfigLocation
and #setConfigLocations methods remain for compatibility with
ContextLoader-style initialization, but have been locally overridden
and documented clearly.
AnnotationConfigWebApplicationContext#loadBeanDefinitions Javadoc has
also been updated to explain the processing logic for each of these
potential inputs.
Issue: SPR-8320
This new hook in the AbstractEnvironment lifecycle allows for more
explicit and predictable customization of property sources by
subclasses. See Javadoc and existing implementations for detail.
Issue: SPR-8354
Designed primarily for use in conjunction with web applications
to provide a convenient mechanism for configuring the container
programmatically.
ApplicationContextInitializer implementations are specified through the
new "contextInitializerClasses" servlet context parameter, then detected
and invoked by ContextLoader in its customizeContext() method.
In any case, the semantics of ApplicationContextInitializer's
initialize(ConfigurableApplicationContext) method require that
invocation occur *prior* to refreshing the application context.
ACI implementations may also implement Ordered/PriorityOrdered and
ContextLoader will sort instances appropriately prior to invocation.
Specifically, this new support provides a straightforward way to
programmatically access the container's Environment for the purpose
of adding, removing or otherwise manipulating PropertySource objects.
See Javadoc for further details.
Also note that ApplicationContextInitializer semantics overlap to
some degree with Servlet 3.0's notion of ServletContainerInitializer
classes. As Spring 3.1 development progresses, we'll likely see
these two come together and further influence one another.
DefaultWebEnvironment automatically adds a JndiPropertySource if
a "jndiPropertySourceEnabled" property is detected in any of the
other other default property sources.
* Environment now extends PropertyResolver
* Environment no longer exposes resolver and sources
* PropertySource is String,Object instead of String,String
* PropertySource no longer assumes enumerability of property names
* Introduced EnumerablePropertySource for those that do have enumerable property names
All existing *Aware interfaces have been refactored to extend this
new marker interface, serving two purposes:
* Easy access to a type hierarchy that can answer the question
"What *Aware interfaces are available?", without requiring
text-based searches. Also clearly excludes false positives like
TargetClassAware and ParamAware, which while similarly named,
are not semantically similar to traditional *Aware interfaces
in Spring.
* Minor potential performance improvements in
AbstractAutowireCapableBeanFactory and
ApplicationContextAwareProcessor. Both have blocks of sequential
instanceof checks in order to invoke any *Aware interface callback
methods. For a bean that implements none of these interfaces,
the whole sequence can be avoided by guarding first with
if (bean instanceof Aware) {
...
}
Implementors of custom *Aware-style interfaces (and presumably
the BeanPostProcessors that handle them), are encouraged to refactor to
extending this interface for consistency with the framework as well as
the points above.
Chris Beams
Arjen Poutsma
Rossen Stoyanchev
Micha Kiener
Juergen Hoeller