public interface ComponentDefinition extends BeanMetadataElement
BeanDefinitions
and BeanReferences as presented in some configuration context.
With the introduction of pluggable custom XML tags,
it is now possible for a single logical configuration entity, in this case an XML tag, to
create multiple BeanDefinitions and RuntimeBeanReferences
in order to provide more succinct configuration and greater convenience to end users. As such, it can
no longer be assumed that each configuration entity (e.g. XML tag) maps to one BeanDefinition.
For tool vendors and other users who wish to present visualization or support for configuring Spring
applications it is important that there is some mechanism in place to tie the BeanDefinitions
in the BeanFactory back to the configuration data in a way
that has concrete meaning to the end user. As such, NamespaceHandler
implementations are able to publish events in the form of a ComponentDefinition for each
logical entity being configured. Third parties can then subscribe to these events,
allowing for a user-centric view of the bean metadata.
Each ComponentDefinition has a source object which is configuration-specific.
In the case of XML-based configuration this is typically the Node which contains the user
supplied configuration information. In addition to this, each BeanDefinition enclosed in a
ComponentDefinition has its own source object which may point
to a different, more specific, set of configuration data. Beyond this, individual pieces of bean metadata such
as the PropertyValues may also have a source object giving an
even greater level of detail. Source object extraction is handled through the
SourceExtractor which can be customized as required.
Whilst direct access to important BeanReferences is provided through
getBeanReferences(), tools may wish to inspect all BeanDefinitions to gather
the full set of BeanReferences. Implementations are required to provide
all BeanReferences that are required to validate the configuration of the
overall logical entity as well as those required to provide full user visualisation of the configuration.
It is expected that certain BeanReferences will not be important to
validation or to the user view of the configuration and as such these may be ommitted. A tool may wish to
display any additional BeanReferences sourced through the supplied
BeanDefinitions but this is not considered to be a typical case.
Tools can determine the important of contained BeanDefinitions by checking the
role identifier. The role is essentially a hint to the tool as to how
important the configuration provider believes a BeanDefinition is to the end user. It is expected
that tools will not display all BeanDefinitions for a given
ComponentDefinition choosing instead to filter based on the role. Tools may choose to make
this filtering user configurable. Particular notice should be given to the
INFRASTRUCTURE role identifier. BeanDefinitions
classified with this role are completely unimportant to the end user and are required only for
internal implementation reasons.
AbstractComponentDefinition,
CompositeComponentDefinition,
BeanComponentDefinition,
ReaderEventListener.componentRegistered(ComponentDefinition)| Modifier and Type | Method and Description |
|---|---|
BeanDefinition[] |
getBeanDefinitions()
Return the
BeanDefinitions that were registered
to form this ComponentDefinition. |
BeanReference[] |
getBeanReferences()
Return the set of
BeanReferences that are considered
to be important to this ComponentDefinition. |
java.lang.String |
getDescription()
Return a friendly description of the described component.
|
BeanDefinition[] |
getInnerBeanDefinitions()
Return the
BeanDefinitions that represent all relevant
inner beans within this component. |
java.lang.String |
getName()
Get the user-visible name of this
ComponentDefinition. |
getSourcejava.lang.String getName()
ComponentDefinition.
This should link back directly to the corresponding configuration data for this component in a given context.
java.lang.String getDescription()
Implementations are encouraged to return the same value from
toString().
BeanDefinition[] getBeanDefinitions()
BeanDefinitions that were registered
to form this ComponentDefinition.
It should be noted that a ComponentDefinition may well be related with
other BeanDefinitions via references,
however these are not included as they may be not available immediately.
Important BeanReferences are available from getBeanReferences().
BeanDefinition[] getInnerBeanDefinitions()
BeanDefinitions that represent all relevant
inner beans within this component.
Other inner beans may exist within the associated BeanDefinitions,
however these are not considered to be needed for validation or for user visualization.
BeanReference[] getBeanReferences()
BeanReferences that are considered
to be important to this ComponentDefinition.
Other BeanReferences may exist within the associated
BeanDefinitions, however these are not considered
to be needed for validation or for user visualization.