public class RequiredAnnotationBeanPostProcessor extends InstantiationAwareBeanPostProcessorAdapter implements MergedBeanDefinitionPostProcessor, PriorityOrdered, BeanFactoryAware
BeanPostProcessor implementation
that enforces required JavaBean properties to have been configured.
Required bean properties are detected through a Java 5 annotation:
by default, Spring's Required annotation.
The motivation for the existence of this BeanPostProcessor is to allow developers to annotate the setter properties of their own classes with an arbitrary JDK 1.5 annotation to indicate that the container must check for the configuration of a dependency injected value. This neatly pushes responsibility for such checking onto the container (where it arguably belongs), and obviates the need (in part) for a developer to code a method that simply checks that all required properties have actually been set.
Please note that an 'init' method may still need to implemented (and may
still be desirable), because all that this class does is enforce that a
'required' property has actually been configured with a value. It does
not check anything else... In particular, it does not check that a
configured value is not null.
Note: A default RequiredAnnotationBeanPostProcessor 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 RequiredAnnotationBeanPostProcessor bean definition.
setRequiredAnnotationType(java.lang.Class<? extends java.lang.annotation.Annotation>),
Required| Modifier and Type | Field and Description |
|---|---|
static String |
SKIP_REQUIRED_CHECK_ATTRIBUTE
Bean definition attribute that may indicate whether a given bean is supposed
to be skipped when performing this post-processor's required property check.
|
HIGHEST_PRECEDENCE, LOWEST_PRECEDENCE| Constructor and Description |
|---|
RequiredAnnotationBeanPostProcessor() |
| Modifier and Type | Method and Description |
|---|---|
int |
getOrder()
Return the order value of this object, with a
higher value meaning greater in terms of sorting.
|
protected Class<? extends Annotation> |
getRequiredAnnotationType()
Return the 'required' annotation type.
|
protected boolean |
isRequiredProperty(PropertyDescriptor propertyDescriptor)
Is the supplied property required to have a value (that is, to be dependency-injected)?
|
void |
postProcessMergedBeanDefinition(RootBeanDefinition beanDefinition,
Class<?> beanType,
String beanName)
Post-process the given merged bean definition for the specified bean.
|
PropertyValues |
postProcessPropertyValues(PropertyValues pvs,
PropertyDescriptor[] pds,
Object bean,
String beanName)
Post-process the given property values before the factory applies them
to the given bean.
|
void |
setBeanFactory(BeanFactory beanFactory)
Callback that supplies the owning factory to a bean instance.
|
void |
setOrder(int order) |
void |
setRequiredAnnotationType(Class<? extends Annotation> requiredAnnotationType)
Set the 'required' annotation type, to be used on bean property
setter methods.
|
protected boolean |
shouldSkip(ConfigurableListableBeanFactory beanFactory,
String beanName)
Check whether the given bean definition is not subject to the annotation-based
required property check as performed by this post-processor.
|
determineCandidateConstructors, getEarlyBeanReference, postProcessAfterInitialization, postProcessAfterInstantiation, postProcessBeforeInitialization, postProcessBeforeInstantiation, predictBeanTypeclone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, waitpostProcessAfterInitialization, postProcessBeforeInitializationpublic static final String SKIP_REQUIRED_CHECK_ATTRIBUTE
public void setRequiredAnnotationType(Class<? extends Annotation> requiredAnnotationType)
The default required annotation type is the Spring-provided
Required annotation.
This setter property exists so that developers can provide their own (non-Spring-specific) annotation type to indicate that a property value is required.
protected Class<? extends Annotation> getRequiredAnnotationType()
public void setBeanFactory(BeanFactory beanFactory)
BeanFactoryAwareInvoked after the population of normal bean properties
but before an initialization callback such as
InitializingBean.afterPropertiesSet() or a custom init-method.
setBeanFactory in interface BeanFactoryAwarebeanFactory - owning BeanFactory (never null).
The bean can immediately call methods on the factory.BeanInitializationExceptionpublic void setOrder(int order)
public int getOrder()
OrderedNormally starting with 0, with Integer.MAX_VALUE
indicating the greatest value. Same order values will result
in arbitrary positions for the affected objects.
Higher values can be interpreted as lower priority. As a consequence, the object with the lowest value has highest priority (somewhat analogous to Servlet "load-on-startup" values).
public void postProcessMergedBeanDefinition(RootBeanDefinition beanDefinition, Class<?> beanType, String beanName)
MergedBeanDefinitionPostProcessorpostProcessMergedBeanDefinition in interface MergedBeanDefinitionPostProcessorbeanDefinition - the merged bean definition for the beanbeanType - the actual type of the managed bean instancebeanName - the name of the beanpublic PropertyValues postProcessPropertyValues(PropertyValues pvs, PropertyDescriptor[] pds, Object bean, String beanName) throws BeansException
InstantiationAwareBeanPostProcessorAlso allows for replacing the property values to apply, typically through creating a new MutablePropertyValues instance based on the original PropertyValues, adding or removing specific values.
postProcessPropertyValues in interface InstantiationAwareBeanPostProcessorpostProcessPropertyValues in class InstantiationAwareBeanPostProcessorAdapterpvs - the property values that the factory is about to apply (never null)pds - the relevant property descriptors for the target bean (with ignored
dependency types - which the factory handles specifically - already filtered out)bean - the bean instance created, but whose properties have not yet been setbeanName - the name of the beannull
to skip property populationBeansException - in case of errorsMutablePropertyValuesprotected boolean shouldSkip(ConfigurableListableBeanFactory beanFactory, String beanName)
The default implementations check for the presence of the
SKIP_REQUIRED_CHECK_ATTRIBUTE attribute in the bean definition, if any.
beanFactory - the BeanFactory to check againstbeanName - the name of the bean to check againsttrue to skip the bean; false to process itprotected boolean isRequiredProperty(PropertyDescriptor propertyDescriptor)
This implementation looks for the existence of a
"required" annotation
on the supplied property.
propertyDescriptor - the target PropertyDescriptor (never null)true if the supplied property has been marked as being required;
false if not, or if the supplied property does not have a setter method