The Spring Framework

## org.springframework.beans.factory.annotation
Class AutowiredAnnotationBeanPostProcessor

    java.lang.Object
      org.springframework.beans.factory.config.InstantiationAwareBeanPostProcessorAdapter
          org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor

All Implemented Interfaces:
  BeanFactoryAware, BeanPostProcessor, InstantiationAwareBeanPostProcessor, SmartInstantiationAwareBeanPostProcessor, MergedBeanDefinitionPostProcessor, Ordered, PriorityOrdered

    public class AutowiredAnnotationBeanPostProcessor

extends InstantiationAwareBeanPostProcessorAdapter
implements MergedBeanDefinitionPostProcessor, PriorityOrdered, BeanFactoryAware

`BeanPostProcessor` implementation that autowires annotated fields, setter methods and arbitrary config methods. Such members to be injected are detected through a Java 5 annotation: by default, Spring's `Autowired` annotation.

Only one constructor (at max) of any given bean class may carry this annotation with the 'required' parameter set to `true`, indicating the constructor to autowire when used as a Spring bean. If multiple non-required constructors carry 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 default constructor (if present) will be used. An annotated constructor does not have to be public.

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.

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. Such config methods do not have to be public.

Note: 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.

Since:
  2.5
Author:
  Juergen Hoeller, Mark Fisher
See Also:
  `setAutowiredAnnotationType(java.lang.Class<? extends java.lang.annotation.Annotation>)`, `Autowired`, `CommonAnnotationBeanPostProcessor`

Field Summary
`protected Log` `logger`

Fields inherited from interface org.springframework.core.Ordered
`HIGHEST_PRECEDENCE, LOWEST_PRECEDENCE`

Constructor Summary
`AutowiredAnnotationBeanPostProcessor()`

Method Summary
`Constructor[]` `determineCandidateConstructors(Class beanClass, String beanName)` Determine the candidate constructors to use for the given bean.
`protected boolean` `determineRequiredStatus(Annotation annotation)` Determine if the annotated field or method requires its dependency.
`protected Map` `findAutowireCandidates(Class type)` Obtain all beans of the given type as autowire candidates.
`protected Class<? extends Annotation>` `getAutowiredAnnotationType()` Return the 'autowired' annotation type.
`int` `getOrder()` Return the order value of this object, with a higher value meaning greater in terms of sorting.
`boolean` `postProcessAfterInstantiation(Object bean, String beanName)` Perform operations after the bean has been instantiated, via a constructor or factory method, but before Spring property population (from explicit properties or autowiring) occurs.
`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` `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 `@Autowired`.
`void` `setAutowiredAnnotationType(Class<? extends Annotation> autowiredAnnotationType)` Set the 'autowired' annotation type, 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 a parameter of the annotation that specifies whether it is required.
`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 be `false`.

Methods inherited from class org.springframework.beans.factory.config.InstantiationAwareBeanPostProcessorAdapter
`getEarlyBeanReference, postProcessAfterInitialization, postProcessBeforeInitialization, postProcessBeforeInstantiation, predictBeanType`

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`

Field Detail

### logger

    protected final Log logger

Constructor Detail

### AutowiredAnnotationBeanPostProcessor

    public AutowiredAnnotationBeanPostProcessor()

Method Detail

### setAutowiredAnnotationType

    public void setAutowiredAnnotationType(Class<? extends Annotation> autowiredAnnotationType)

  Set the 'autowired' annotation type, to be used on constructors, fields, setter methods and arbitrary config methods.

  The default autowired annotation type is the Spring-provided `Autowired` annotation.

  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.

### getAutowiredAnnotationType

    protected Class<? extends Annotation> getAutowiredAnnotationType()

  Return the 'autowired' annotation type.

### setRequiredParameterName

    public void setRequiredParameterName(String requiredParameterName)

  Set the name of a parameter of the annotation that specifies whether it is required.

  See Also:
    `setRequiredParameterValue(boolean)`

### 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 be `false`.

  See Also:
    `setRequiredParameterName(String)`

### setOrder

    public void setOrder(int order)

### getOrder

    public int getOrder()

  Description copied from interface: `Ordered`
  Return the order value of this object, with a higher value meaning greater in terms of sorting.

  Normally starting with 0 or 1, with `Ordered.LOWEST_PRECEDENCE` indicating greatest. Same order values will result in arbitrary positions for the affected objects.

  Higher value can be interpreted as lower priority, consequently the first object has highest priority (somewhat analogous to Servlet "load-on-startup" values).

  Note that order values below 0 are reserved for framework purposes. Application-specified values should always be 0 or greater, with only framework components (internal or third-party) supposed to use lower values.

  Specified by:
    `getOrder` in interface `Ordered`
  Returns:
    the order value
  See Also:
    `Ordered.LOWEST_PRECEDENCE`

### setBeanFactory

    public void setBeanFactory(BeanFactory beanFactory)
                        throws BeansException

  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 interface `BeanFactoryAware`
  Parameters:
    `beanFactory` - owning BeanFactory (never `null`). The bean can immediately call methods on the factory.
  Throws:
    `BeansException` - in case of initialization errors
  See Also:
    `BeanInitializationException`

### 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 interface `MergedBeanDefinitionPostProcessor`
  Parameters:
    `beanDefinition` - the merged bean definition for the bean
    `beanType` - the actual type of the managed bean instance
    `beanName` - the name of the bean

### determineCandidateConstructors

    public Constructor[] determineCandidateConstructors(Class beanClass,
                                                        String beanName)
                                                 throws BeansException

  Description copied from interface: `SmartInstantiationAwareBeanPostProcessor`
  Determine the candidate constructors to use for the given bean.

  Specified by:
    `determineCandidateConstructors` in interface `SmartInstantiationAwareBeanPostProcessor`
  Overrides:
    `determineCandidateConstructors` in class `InstantiationAwareBeanPostProcessorAdapter`
  Parameters:
    `beanClass` - the raw class of the bean
    `beanName` - the name of the bean
  Returns:
    the candidate constructors, or `null` if none specified
  Throws:
    `BeansException` - in case of errors

### postProcessAfterInstantiation

    public boolean postProcessAfterInstantiation(Object bean,
                                                 String beanName)
                                          throws BeansException

  Description copied from interface: `InstantiationAwareBeanPostProcessor`
  Perform operations after the bean has been instantiated, via a constructor or factory method, but before Spring property population (from explicit properties or autowiring) occurs.

  This is the ideal callback for performing field injection on the given bean instance. See Spring's own `AutowiredAnnotationBeanPostProcessor` for a typical example.

  Specified by:
    `postProcessAfterInstantiation` in interface `InstantiationAwareBeanPostProcessor`
  Overrides:
    `postProcessAfterInstantiation` in class `InstantiationAwareBeanPostProcessorAdapter`
  Parameters:
    `bean` - the bean instance created, with properties not having been set yet
    `beanName` - the name of the bean
  Returns:
    `true` if properties should be set on the bean; `false` if property population should be skipped. Normal implementations should return `true`. Returning `false` will also prevent any subsequent InstantiationAwareBeanPostProcessor instances being invoked on this bean instance.
  Throws:
    `BeansException` - in case of errors

### postProcessPropertyValues

    public PropertyValues postProcessPropertyValues(PropertyValues pvs,
                                                    PropertyDescriptor[] pds,
                                                    Object bean,
                                                    String beanName)
                                             throws BeansException

  Description copied from interface: `InstantiationAwareBeanPostProcessor`
  Post-process the given property values before the factory applies them to the given bean. Allows for checking whether all dependencies have been satisfied, for example based on a "Required" annotation on bean property setters.

  Also 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.

  Specified by:
    `postProcessPropertyValues` in interface `InstantiationAwareBeanPostProcessor`
  Overrides:
    `postProcessPropertyValues` in class `InstantiationAwareBeanPostProcessorAdapter`
  Parameters:
    `pvs` - 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 set
    `beanName` - the name of the bean
  Returns:
    the actual property values to apply to to the given bean (can be the passed-in PropertyValues instance), or `null` to skip property population
  Throws:
    `BeansException` - in case of errors
  See Also:
    `MutablePropertyValues`

### processInjection

    public void processInjection(Object bean)
                          throws BeansException

  'Native' processing method for direct calls with an arbitrary target instance, resolving all of its fields and methods which are annotated with `@Autowired`.

  Parameters:
    `bean` - the target instance to process
  Throws:
    `BeansException`

### findAutowireCandidates

    protected Map findAutowireCandidates(Class type)
                                  throws BeansException

  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

    protected boolean determineRequiredStatus(Annotation annotation)

  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:
    `annotation` - the Autowired annotation
  Returns:
    whether the annotation indicates that a dependency is required

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