Class AutowiredAnnotationBeanPostProcessor
- All Implemented Interfaces:
Aware
,BeanFactoryAware
,BeanPostProcessor
,InstantiationAwareBeanPostProcessor
,SmartInstantiationAwareBeanPostProcessor
,MergedBeanDefinitionPostProcessor
,Ordered
,PriorityOrdered
BeanPostProcessor
implementation that autowires annotated fields, setter methods, and arbitrary
config methods. Such members to be injected are detected through annotations:
by default, Spring's @Autowired
and @Value
annotations.
Also supports the common @Inject
annotation,
if available, as a direct alternative to Spring's own @Autowired
.
Additionally, it retains support for the javax.inject.Inject
variant
dating back to the original JSR-330 specification (as known from Java EE 6-8).
Autowired Constructors
Only one constructor of any given bean class may declare this annotation with
the 'required' attribute set to true
, indicating the constructor
to autowire when used as a Spring bean. Furthermore, if the 'required' attribute
is set to true
, only a single constructor may be annotated with
@Autowired
. If multiple non-required constructors declare the
annotation, they will be considered as candidates for autowiring. The constructor
with the greatest number of dependencies that can be satisfied by matching beans
in the Spring container will be chosen. If none of the candidates can be satisfied,
then a primary/default constructor (if present) will be used. If a class only
declares a single constructor to begin with, it will always be used, even if not
annotated. An annotated constructor does not have to be public.
Autowired Fields
Fields are injected right after construction of a bean, before any config methods are invoked. Such a config field does not have to be public.
Autowired Methods
Config methods may have an arbitrary name and any number of arguments; each of those arguments will be autowired with a matching bean in the Spring container. Bean property setter methods are effectively just a special case of such a general config method. Config methods do not have to be public.
Annotation Config vs. XML Config
A default AutowiredAnnotationBeanPostProcessor
will be registered
by the "context:annotation-config" and "context:component-scan" XML tags.
Remove or turn off the default annotation configuration there if you intend
to specify a custom AutowiredAnnotationBeanPostProcessor
bean definition.
NOTE: Annotation injection will be performed before XML injection; thus the latter configuration will override the former for properties wired through both approaches.
@Lookup Methods
In addition to regular injection points as discussed above, this post-processor
also handles Spring's @Lookup
annotation which identifies lookup
methods to be replaced by the container at runtime. This is essentially a type-safe
version of getBean(Class, args)
and getBean(String, args)
.
See @Lookup's javadoc
for details.
- Since:
- 2.5
- Author:
- Juergen Hoeller, Mark Fisher, Stephane Nicoll, Sebastien Deleuze, Sam Brannen
- See Also:
-
Field Summary
FieldsFields inherited from interface org.springframework.core.Ordered
HIGHEST_PRECEDENCE, LOWEST_PRECEDENCE
-
Constructor Summary
ConstructorsConstructorDescriptionCreate a newAutowiredAnnotationBeanPostProcessor
for Spring's standard@Autowired
and@Value
annotations. -
Method Summary
Modifier and TypeMethodDescriptionConstructor<?>[]
determineCandidateConstructors
(Class<?> beanClass, String beanName) Determine the candidate constructors to use for the given bean.protected boolean
Deprecated.protected boolean
Determine if the annotated field or method requires its dependency.findAutowireCandidates
(Class<T> type) Obtain all beans of the given type as autowire candidates.int
getOrder()
Get the order value of this object.void
postProcessMergedBeanDefinition
(RootBeanDefinition beanDefinition, Class<?> beanType, String beanName) Post-process the given merged bean definition for the specified bean.postProcessProperties
(PropertyValues pvs, Object bean, String beanName) Post-process the given property values before the factory applies them to the given bean.void
processInjection
(Object bean) 'Native' processing method for direct calls with an arbitrary target instance, resolving all of its fields and methods which are annotated with one of the configured 'autowired' annotation types.void
resetBeanDefinition
(String beanName) A notification that the bean definition for the specified name has been reset, and that this post-processor should clear any metadata for the affected bean.void
setAutowiredAnnotationType
(Class<? extends Annotation> autowiredAnnotationType) Set the 'autowired' annotation type, to be used on constructors, fields, setter methods, and arbitrary config methods.void
setAutowiredAnnotationTypes
(Set<Class<? extends Annotation>> autowiredAnnotationTypes) Set the 'autowired' annotation types, to be used on constructors, fields, setter methods, and arbitrary config methods.void
setBeanFactory
(BeanFactory beanFactory) Callback that supplies the owning factory to a bean instance.void
setOrder
(int order) void
setRequiredParameterName
(String requiredParameterName) Set the name of an attribute of the annotation that specifies whether it is required.void
setRequiredParameterValue
(boolean requiredParameterValue) Set the boolean value that marks a dependency as required.Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Methods inherited from interface org.springframework.beans.factory.config.BeanPostProcessor
postProcessAfterInitialization, postProcessBeforeInitialization
Methods inherited from interface org.springframework.beans.factory.config.InstantiationAwareBeanPostProcessor
postProcessAfterInstantiation, postProcessBeforeInstantiation
Methods inherited from interface org.springframework.beans.factory.config.SmartInstantiationAwareBeanPostProcessor
getEarlyBeanReference, predictBeanType
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Field Details
-
logger
-
-
Constructor Details
-
AutowiredAnnotationBeanPostProcessor
public AutowiredAnnotationBeanPostProcessor()Create a newAutowiredAnnotationBeanPostProcessor
for Spring's standard@Autowired
and@Value
annotations.Also supports the common
@Inject
annotation, if available, as well as the originaljavax.inject.Inject
variant.
-
-
Method Details
-
setAutowiredAnnotationType
Set the 'autowired' annotation type, to be used on constructors, fields, setter methods, and arbitrary config methods.The default autowired annotation types are the Spring-provided
@Autowired
and@Value
annotations as well as the common@Inject
annotation, if available.This setter property exists so that developers can provide their own (non-Spring-specific) annotation type to indicate that a member is supposed to be autowired.
-
setAutowiredAnnotationTypes
Set the 'autowired' annotation types, to be used on constructors, fields, setter methods, and arbitrary config methods.The default autowired annotation types are the Spring-provided
@Autowired
and@Value
annotations as well as the common@Inject
annotation, if available.This setter property exists so that developers can provide their own (non-Spring-specific) annotation types to indicate that a member is supposed to be autowired.
-
setRequiredParameterName
Set the name of an attribute of the annotation that specifies whether it is required.- See Also:
-
setRequiredParameterValue
public void setRequiredParameterValue(boolean requiredParameterValue) Set the boolean value that marks a dependency as required.For example if using 'required=true' (the default), this value should be
true
; but if using 'optional=false', this value should befalse
.- See Also:
-
setOrder
public void setOrder(int order) -
getOrder
public int getOrder()Description copied from interface:Ordered
Get the order value of this object.Higher values are interpreted as lower priority. As a consequence, the object with the lowest value has the highest priority (somewhat analogous to Servlet
load-on-startup
values).Same order values will result in arbitrary sort positions for the affected objects.
-
setBeanFactory
Description copied from interface:BeanFactoryAware
Callback that supplies the owning factory to a bean instance.Invoked after the population of normal bean properties but before an initialization callback such as
InitializingBean.afterPropertiesSet()
or a custom init-method.- Specified by:
setBeanFactory
in interfaceBeanFactoryAware
- Parameters:
beanFactory
- owning BeanFactory (nevernull
). The bean can immediately call methods on the factory.- See Also:
-
postProcessMergedBeanDefinition
public void postProcessMergedBeanDefinition(RootBeanDefinition beanDefinition, Class<?> beanType, String beanName) Description copied from interface:MergedBeanDefinitionPostProcessor
Post-process the given merged bean definition for the specified bean.- Specified by:
postProcessMergedBeanDefinition
in interfaceMergedBeanDefinitionPostProcessor
- Parameters:
beanDefinition
- the merged bean definition for the beanbeanType
- the actual type of the managed bean instancebeanName
- the name of the bean- See Also:
-
resetBeanDefinition
Description copied from interface:MergedBeanDefinitionPostProcessor
A notification that the bean definition for the specified name has been reset, and that this post-processor should clear any metadata for the affected bean.The default implementation is empty.
- Specified by:
resetBeanDefinition
in interfaceMergedBeanDefinitionPostProcessor
- Parameters:
beanName
- the name of the bean- See Also:
-
determineCandidateConstructors
@Nullable public Constructor<?>[] determineCandidateConstructors(Class<?> beanClass, String beanName) throws BeanCreationException Description copied from interface:SmartInstantiationAwareBeanPostProcessor
Determine the candidate constructors to use for the given bean.The default implementation returns
null
.- Specified by:
determineCandidateConstructors
in interfaceSmartInstantiationAwareBeanPostProcessor
- Parameters:
beanClass
- the raw class of the bean (nevernull
)beanName
- the name of the bean- Returns:
- the candidate constructors, or
null
if none specified - Throws:
BeanCreationException
-
postProcessProperties
Description copied from interface:InstantiationAwareBeanPostProcessor
Post-process the given property values before the factory applies them to the given bean.The default implementation returns the given
pvs
as-is.- Specified by:
postProcessProperties
in interfaceInstantiationAwareBeanPostProcessor
- Parameters:
pvs
- the property values that the factory is about to apply (nevernull
)bean
- the bean instance created, but whose properties have not yet been setbeanName
- the name of the bean- Returns:
- the actual property values to apply to the given bean (can be the passed-in
PropertyValues instance), or
null
to skip property population
-
processInjection
'Native' processing method for direct calls with an arbitrary target instance, resolving all of its fields and methods which are annotated with one of the configured 'autowired' annotation types.- Parameters:
bean
- the target instance to process- Throws:
BeanCreationException
- if autowiring failed- See Also:
-
determineRequiredStatus
Determine if the annotated field or method requires its dependency.A 'required' dependency means that autowiring should fail when no beans are found. Otherwise, the autowiring process will simply bypass the field or method when no beans are found.
- Parameters:
ann
- the Autowired annotation- Returns:
- whether the annotation indicates that a dependency is required
-
determineRequiredStatus
Deprecated.since 5.2, in favor ofdetermineRequiredStatus(MergedAnnotation)
Determine if the annotated field or method requires its dependency.A 'required' dependency means that autowiring should fail when no beans are found. Otherwise, the autowiring process will simply bypass the field or method when no beans are found.
- Parameters:
ann
- the Autowired annotation- Returns:
- whether the annotation indicates that a dependency is required
-
findAutowireCandidates
Obtain all beans of the given type as autowire candidates.- Parameters:
type
- the type of the bean- Returns:
- the target beans, or an empty Collection if no bean of this type is found
- Throws:
BeansException
- if bean retrieval failed
-
determineRequiredStatus(MergedAnnotation)