org.springframework.beans.factory.support

Interface AutowireCandidateResolver

All Known Implementing Classes:

ContextAnnotationAutowireCandidateResolver, GenericTypeAwareAutowireCandidateResolver, QualifierAnnotationAutowireCandidateResolver, SimpleAutowireCandidateResolver

public interface AutowireCandidateResolver

Strategy interface for determining whether a specific bean definition qualifies as an autowire candidate for a specific dependency.

Since:

2.5

Author:

Juergen Hoeller, Mark Fisher

Method Summary

Modifier and Type	Method and Description
default AutowireCandidateResolver	cloneIfNecessary() Return a clone of this resolver instance if necessary, retaining its local configuration and allowing for the cloned instance to get associated with a new bean factory, or this original instance if there is no such state.
default Object	getLazyResolutionProxyIfNecessary(DependencyDescriptor descriptor, String beanName) Build a proxy for lazy resolution of the actual dependency target, if demanded by the injection point.
default Object	getSuggestedValue(DependencyDescriptor descriptor) Determine whether a default value is suggested for the given dependency.
default boolean	hasQualifier(DependencyDescriptor descriptor) Determine whether the given descriptor declares a qualifier beyond the type (typically - but not necessarily - a specific kind of annotation).
default boolean	isAutowireCandidate(BeanDefinitionHolder bdHolder, DependencyDescriptor descriptor) Determine whether the given bean definition qualifies as an autowire candidate for the given dependency.
default boolean	isRequired(DependencyDescriptor descriptor) Determine whether the given descriptor is effectively required.

Method Detail

isAutowireCandidate

default boolean isAutowireCandidate(BeanDefinitionHolder bdHolder,
                                    DependencyDescriptor descriptor)

Determine whether the given bean definition qualifies as an autowire candidate for the given dependency.

The default implementation checks BeanDefinition.isAutowireCandidate().

Parameters:

bdHolder - the bean definition including bean name and aliases

descriptor - the descriptor for the target method parameter or field

Returns:

whether the bean definition qualifies as autowire candidate

See Also:

BeanDefinition.isAutowireCandidate()

isRequired

default boolean isRequired(DependencyDescriptor descriptor)

Determine whether the given descriptor is effectively required.

The default implementation checks DependencyDescriptor.isRequired().

Parameters:

descriptor - the descriptor for the target method parameter or field

Returns:

whether the descriptor is marked as required or possibly indicating non-required status some other way (e.g. through a parameter annotation)

Since:

5.0

See Also:

DependencyDescriptor.isRequired()

hasQualifier

default boolean hasQualifier(DependencyDescriptor descriptor)

Determine whether the given descriptor declares a qualifier beyond the type (typically - but not necessarily - a specific kind of annotation).

The default implementation returns false.

Parameters:

descriptor - the descriptor for the target method parameter or field

Returns:

whether the descriptor declares a qualifier, narrowing the candidate status beyond the type match

Since:

5.1

See Also:

QualifierAnnotationAutowireCandidateResolver.hasQualifier(org.springframework.beans.factory.config.DependencyDescriptor)

getSuggestedValue

@Nullable
default Object getSuggestedValue(DependencyDescriptor descriptor)

Determine whether a default value is suggested for the given dependency.

The default implementation simply returns null.

Parameters:

descriptor - the descriptor for the target method parameter or field

Returns:

the value suggested (typically an expression String), or null if none found

Since:

3.0

getLazyResolutionProxyIfNecessary

@Nullable
default Object getLazyResolutionProxyIfNecessary(DependencyDescriptor descriptor,
                                                           @Nullable
                                                           String beanName)

Build a proxy for lazy resolution of the actual dependency target, if demanded by the injection point.

The default implementation simply returns null.

Parameters:

descriptor - the descriptor for the target method parameter or field

beanName - the name of the bean that contains the injection point

Returns:

the lazy resolution proxy for the actual dependency target, or null if straight resolution is to be performed

Since:

4.0

cloneIfNecessary

default AutowireCandidateResolver cloneIfNecessary()

Return a clone of this resolver instance if necessary, retaining its local configuration and allowing for the cloned instance to get associated with a new bean factory, or this original instance if there is no such state.

The default implementation creates a separate instance via the default class constructor, assuming no specific configuration state to copy. Subclasses may override this with custom configuration state handling or with standard Cloneable support (as implemented by Spring's own configurable AutowireCandidateResolver variants), or simply return this (as in SimpleAutowireCandidateResolver).

Since:

5.2.7

See Also:

GenericTypeAwareAutowireCandidateResolver.cloneIfNecessary(), DefaultListableBeanFactory.copyConfigurationFrom(org.springframework.beans.factory.config.ConfigurableBeanFactory)