org.springframework.aop.framework.autoproxy

Class AbstractAutoProxyCreator

java.lang.Object

org.springframework.aop.framework.ProxyConfig

org.springframework.aop.framework.ProxyProcessorSupport

org.springframework.aop.framework.autoproxy.AbstractAutoProxyCreator

All Implemented Interfaces:

Serializable, AopInfrastructureBean, Aware, BeanClassLoaderAware, BeanFactoryAware, BeanPostProcessor, InstantiationAwareBeanPostProcessor, SmartInstantiationAwareBeanPostProcessor, Ordered

Direct Known Subclasses:

AbstractAdvisorAutoProxyCreator, BeanNameAutoProxyCreator

public abstract class AbstractAutoProxyCreator
extends ProxyProcessorSupport
implements SmartInstantiationAwareBeanPostProcessor, BeanFactoryAware

BeanPostProcessor implementation that wraps each eligible bean with an AOP proxy, delegating to specified interceptors before invoking the bean itself.

This class distinguishes between "common" interceptors: shared for all proxies it creates, and "specific" interceptors: unique per bean instance. There need not be any common interceptors. If there are, they are set using the interceptorNames property. As with ProxyFactoryBean, interceptors names in the current factory are used rather than bean references to allow correct handling of prototype advisors and interceptors: for example, to support stateful mixins. Any advice type is supported for "interceptorNames" entries.

Such auto-proxying is particularly useful if there's a large number of beans that need to be wrapped with similar proxies, i.e. delegating to the same interceptors. Instead of x repetitive proxy definitions for x target beans, you can register one single such post processor with the bean factory to achieve the same effect.

Subclasses can apply any strategy to decide if a bean is to be proxied, e.g. by type, by name, by definition details, etc. They can also return additional interceptors that should just be applied to the specific bean instance. A simple concrete implementation is BeanNameAutoProxyCreator, identifying the beans to be proxied via given names.

Any number of TargetSourceCreator implementations can be used to create a custom target source: for example, to pool prototype objects. Auto-proxying will occur even if there is no advice, as long as a TargetSourceCreator specifies a custom TargetSource. If there are no TargetSourceCreators set, or if none matches, a SingletonTargetSource will be used by default to wrap the target bean instance.

Since:

13.10.2003

Author:

Juergen Hoeller, Rod Johnson, Rob Harrop

See Also:

setInterceptorNames(java.lang.String...), getAdvicesAndAdvisorsForBean(java.lang.Class<?>, java.lang.String, org.springframework.aop.TargetSource), BeanNameAutoProxyCreator, DefaultAdvisorAutoProxyCreator, Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected static Object[]	DO_NOT_PROXY Convenience constant for subclasses: Return value for "do not proxy".
protected Log	logger Logger available to subclasses.
protected static Object[]	PROXY_WITHOUT_ADDITIONAL_INTERCEPTORS Convenience constant for subclasses: Return value for "proxy without additional interceptors, just the common ones".

Fields inherited from interface org.springframework.core.Ordered

HIGHEST_PRECEDENCE, LOWEST_PRECEDENCE

Constructor Summary

Constructors

Constructor and Description
AbstractAutoProxyCreator()

Method Summary

Modifier and Type	Method and Description
protected boolean	advisorsPreFiltered() Return whether the Advisors returned by the subclass are pre-filtered to match the bean's target class already, allowing the ClassFilter check to be skipped when building advisors chains for AOP invocations.
protected Advisor[]	buildAdvisors(String beanName, Object[] specificInterceptors) Determine the advisors for the given bean, including the specific interceptors as well as the common interceptor, all adapted to the Advisor interface.
protected Object	createProxy(Class<?> beanClass, String beanName, Object[] specificInterceptors, TargetSource targetSource) Create an AOP proxy for the given bean.
protected void	customizeProxyFactory(ProxyFactory proxyFactory) Subclasses may choose to implement this: for example, to change the interfaces exposed.
Constructor<?>[]	determineCandidateConstructors(Class<?> beanClass, String beanName) Determine the candidate constructors to use for the given bean.
protected abstract Object[]	getAdvicesAndAdvisorsForBean(Class<?> beanClass, String beanName, TargetSource customTargetSource) Return whether the given bean is to be proxied, what additional advices (e.g.
protected BeanFactory	getBeanFactory() Return the owning BeanFactory.
protected Object	getCacheKey(Class<?> beanClass, String beanName) Build a cache key for the given bean class and bean name.
protected TargetSource	getCustomTargetSource(Class<?> beanClass, String beanName) Create a target source for bean instances.
Object	getEarlyBeanReference(Object bean, String beanName) Obtain a reference for early access to the specified bean, typically for the purpose of resolving a circular reference.
boolean	isFrozen() Return whether the config is frozen, and no advice changes can be made.
protected boolean	isInfrastructureClass(Class<?> beanClass) Return whether the given bean class represents an infrastructure class that should never be proxied.
Object	postProcessAfterInitialization(Object bean, String beanName) Create a proxy with the configured interceptors if the bean is identified as one to proxy by the subclass.
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.
Object	postProcessBeforeInitialization(Object bean, String beanName) Apply this BeanPostProcessor to the given new bean instance before any bean initialization callbacks (like InitializingBean's afterPropertiesSet or a custom init-method).
Object	postProcessBeforeInstantiation(Class<?> beanClass, String beanName) Apply this BeanPostProcessor before the target bean gets instantiated.
PropertyValues	postProcessProperties(PropertyValues pvs, Object bean, String beanName) Post-process the given property values before the factory applies them to the given bean, without any need for property descriptors.
Class<?>	predictBeanType(Class<?> beanClass, String beanName) Predict the type of the bean to be eventually returned from this processor's InstantiationAwareBeanPostProcessor.postProcessBeforeInstantiation(java.lang.Class<?>, java.lang.String) callback.
void	setAdvisorAdapterRegistry(AdvisorAdapterRegistry advisorAdapterRegistry) Specify the AdvisorAdapterRegistry to use.
void	setApplyCommonInterceptorsFirst(boolean applyCommonInterceptorsFirst) Set whether the common interceptors should be applied before bean-specific ones.
void	setBeanFactory(BeanFactory beanFactory) Callback that supplies the owning factory to a bean instance.
void	setCustomTargetSourceCreators(TargetSourceCreator... targetSourceCreators) Set custom TargetSourceCreators to be applied in this order.
void	setFrozen(boolean frozen) Set whether or not the proxy should be frozen, preventing advice from being added to it once it is created.
void	setInterceptorNames(String... interceptorNames) Set the common interceptors.
protected boolean	shouldProxyTargetClass(Class<?> beanClass, String beanName) Determine whether the given bean should be proxied with its target class rather than its interfaces.
protected boolean	shouldSkip(Class<?> beanClass, String beanName) Subclasses should override this method to return true if the given bean should not be considered for auto-proxying by this post-processor.
protected Object	wrapIfNecessary(Object bean, String beanName, Object cacheKey) Wrap the given bean if necessary, i.e.

Methods inherited from class org.springframework.aop.framework.ProxyProcessorSupport

evaluateProxyInterfaces, getOrder, getProxyClassLoader, isConfigurationCallbackInterface, isInternalLanguageInterface, setBeanClassLoader, setOrder, setProxyClassLoader

Methods inherited from class org.springframework.aop.framework.ProxyConfig

copyFrom, isExposeProxy, isOpaque, isOptimize, isProxyTargetClass, setExposeProxy, setOpaque, setOptimize, setProxyTargetClass, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.springframework.beans.factory.config.InstantiationAwareBeanPostProcessor

postProcessPropertyValues

Field Detail

DO_NOT_PROXY

@Nullable
protected static final Object[] DO_NOT_PROXY

Convenience constant for subclasses: Return value for "do not proxy".

See Also:

getAdvicesAndAdvisorsForBean(java.lang.Class<?>, java.lang.String, org.springframework.aop.TargetSource)

PROXY_WITHOUT_ADDITIONAL_INTERCEPTORS

protected static final Object[] PROXY_WITHOUT_ADDITIONAL_INTERCEPTORS

Convenience constant for subclasses: Return value for "proxy without additional interceptors, just the common ones".

See Also:

getAdvicesAndAdvisorsForBean(java.lang.Class<?>, java.lang.String, org.springframework.aop.TargetSource)

logger

protected final Log logger

Logger available to subclasses.

Constructor Detail

AbstractAutoProxyCreator

public AbstractAutoProxyCreator()

Method Detail

setFrozen

public void setFrozen(boolean frozen)

Set whether or not the proxy should be frozen, preventing advice from being added to it once it is created.

Overridden from the super class to prevent the proxy configuration from being frozen before the proxy is created.

Overrides:

setFrozen in class ProxyConfig

isFrozen

public boolean isFrozen()

Description copied from class: ProxyConfig

Return whether the config is frozen, and no advice changes can be made.

Overrides:

isFrozen in class ProxyConfig

setAdvisorAdapterRegistry

public void setAdvisorAdapterRegistry(AdvisorAdapterRegistry advisorAdapterRegistry)

Specify the AdvisorAdapterRegistry to use.

Default is the global AdvisorAdapterRegistry.

See Also:

GlobalAdvisorAdapterRegistry

setCustomTargetSourceCreators

public void setCustomTargetSourceCreators(TargetSourceCreator... targetSourceCreators)

Set custom TargetSourceCreators to be applied in this order. If the list is empty, or they all return null, a SingletonTargetSource will be created for each bean.

Note that TargetSourceCreators will kick in even for target beans where no advices or advisors have been found. If a TargetSourceCreator returns a TargetSource for a specific bean, that bean will be proxied in any case.

TargetSourceCreators can only be invoked if this post processor is used in a BeanFactory and its BeanFactoryAware callback is triggered.

Parameters:

targetSourceCreators - the list of TargetSourceCreators. Ordering is significant: The TargetSource returned from the first matching TargetSourceCreator (that is, the first that returns non-null) will be used.

setInterceptorNames

public void setInterceptorNames(String... interceptorNames)

Set the common interceptors. These must be bean names in the current factory. They can be of any advice or advisor type Spring supports.

If this property isn't set, there will be zero common interceptors. This is perfectly valid, if "specific" interceptors such as matching Advisors are all we want.

setApplyCommonInterceptorsFirst

public void setApplyCommonInterceptorsFirst(boolean applyCommonInterceptorsFirst)

Set whether the common interceptors should be applied before bean-specific ones. Default is "true"; else, bean-specific interceptors will get applied first.

setBeanFactory

public void setBeanFactory(BeanFactory beanFactory)

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.

See Also:

BeanInitializationException

getBeanFactory

@Nullable
protected BeanFactory getBeanFactory()

Return the owning BeanFactory. May be null, as this post-processor doesn't need to belong to a bean factory.

predictBeanType

@Nullable
public Class<?> predictBeanType(Class<?> beanClass,
                                          String beanName)

Description copied from interface: SmartInstantiationAwareBeanPostProcessor

Predict the type of the bean to be eventually returned from this processor's InstantiationAwareBeanPostProcessor.postProcessBeforeInstantiation(java.lang.Class<?>, java.lang.String) callback.

The default implementation returns null.

Specified by:

predictBeanType in interface SmartInstantiationAwareBeanPostProcessor

Parameters:

beanClass - the raw class of the bean

beanName - the name of the bean

Returns:

the type of the bean, or null if not predictable

determineCandidateConstructors

@Nullable
public Constructor<?>[] determineCandidateConstructors(Class<?> beanClass,
                                                                 String beanName)

Description copied from interface: SmartInstantiationAwareBeanPostProcessor

Determine the candidate constructors to use for the given bean.

The default implementation returns null.

Specified by:

determineCandidateConstructors in interface SmartInstantiationAwareBeanPostProcessor

Parameters:

beanClass - the raw class of the bean (never null)

beanName - the name of the bean

Returns:

the candidate constructors, or null if none specified

getEarlyBeanReference

public Object getEarlyBeanReference(Object bean,
                                    String beanName)

Description copied from interface: SmartInstantiationAwareBeanPostProcessor

Obtain a reference for early access to the specified bean, typically for the purpose of resolving a circular reference.

This callback gives post-processors a chance to expose a wrapper early - that is, before the target bean instance is fully initialized. The exposed object should be equivalent to the what BeanPostProcessor.postProcessBeforeInitialization(java.lang.Object, java.lang.String) / BeanPostProcessor.postProcessAfterInitialization(java.lang.Object, java.lang.String) would expose otherwise. Note that the object returned by this method will be used as bean reference unless the post-processor returns a different wrapper from said post-process callbacks. In other words: Those post-process callbacks may either eventually expose the same reference or alternatively return the raw bean instance from those subsequent callbacks (if the wrapper for the affected bean has been built for a call to this method already, it will be exposes as final bean reference by default).

The default implementation returns the given bean as-is.

Specified by:

getEarlyBeanReference in interface SmartInstantiationAwareBeanPostProcessor

Parameters:

bean - the raw bean instance

beanName - the name of the bean

Returns:

the object to expose as bean reference (typically with the passed-in bean instance as default)

postProcessBeforeInstantiation

public Object postProcessBeforeInstantiation(Class<?> beanClass,
                                             String beanName)

Description copied from interface: InstantiationAwareBeanPostProcessor

Apply this BeanPostProcessor before the target bean gets instantiated. The returned bean object may be a proxy to use instead of the target bean, effectively suppressing default instantiation of the target bean.

If a non-null object is returned by this method, the bean creation process will be short-circuited. The only further processing applied is the BeanPostProcessor.postProcessAfterInitialization(java.lang.Object, java.lang.String) callback from the configured BeanPostProcessors.

This callback will be applied to bean definitions with their bean class, as well as to factory-method definitions in which case the returned bean type will be passed in here.

Post-processors may implement the extended SmartInstantiationAwareBeanPostProcessor interface in order to predict the type of the bean object that they are going to return here.

The default implementation returns null.

Specified by:

postProcessBeforeInstantiation in interface InstantiationAwareBeanPostProcessor

Parameters:

beanClass - the class of the bean to be instantiated

beanName - the name of the bean

Returns:

the bean object to expose instead of a default instance of the target bean, or null to proceed with default instantiation

See Also:

InstantiationAwareBeanPostProcessor.postProcessAfterInstantiation(java.lang.Object, java.lang.String), AbstractBeanDefinition.getBeanClass(), AbstractBeanDefinition.getFactoryMethodName()

postProcessAfterInstantiation

public boolean postProcessAfterInstantiation(Object bean,
                                             String beanName)

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 custom field injection on the given bean instance, right before Spring's autowiring kicks in.

The default implementation returns true.

Specified by:

postProcessAfterInstantiation in interface InstantiationAwareBeanPostProcessor

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.

See Also:

InstantiationAwareBeanPostProcessor.postProcessBeforeInstantiation(java.lang.Class<?>, java.lang.String)

postProcessProperties

public PropertyValues postProcessProperties(PropertyValues pvs,
                                            Object bean,
                                            String beanName)

Description copied from interface: InstantiationAwareBeanPostProcessor

Post-process the given property values before the factory applies them to the given bean, without any need for property descriptors.

Implementations should return null (the default) if they provide a custom InstantiationAwareBeanPostProcessor.postProcessPropertyValues(org.springframework.beans.PropertyValues, java.beans.PropertyDescriptor[], java.lang.Object, java.lang.String) implementation, and pvs otherwise. In a future version of this interface (with InstantiationAwareBeanPostProcessor.postProcessPropertyValues(org.springframework.beans.PropertyValues, java.beans.PropertyDescriptor[], java.lang.Object, java.lang.String) removed), the default implementation will return the given pvs as-is directly.

Specified by:

postProcessProperties in interface InstantiationAwareBeanPostProcessor

Parameters:

pvs - the property values that the factory is about to apply (never null)

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 the given bean (can be the passed-in PropertyValues instance), or null which proceeds with the existing properties but specifically continues with a call to InstantiationAwareBeanPostProcessor.postProcessPropertyValues(org.springframework.beans.PropertyValues, java.beans.PropertyDescriptor[], java.lang.Object, java.lang.String) (requiring initialized PropertyDescriptors for the current bean class)

See Also:

InstantiationAwareBeanPostProcessor.postProcessPropertyValues(org.springframework.beans.PropertyValues, java.beans.PropertyDescriptor[], java.lang.Object, java.lang.String)

postProcessBeforeInitialization

public Object postProcessBeforeInitialization(Object bean,
                                              String beanName)

Description copied from interface: BeanPostProcessor

Apply this BeanPostProcessor to the given new bean instance before any bean initialization callbacks (like InitializingBean's afterPropertiesSet or a custom init-method). The bean will already be populated with property values. The returned bean instance may be a wrapper around the original.

The default implementation returns the given bean as-is.

Specified by:

postProcessBeforeInitialization in interface BeanPostProcessor

Parameters:

bean - the new bean instance

beanName - the name of the bean

Returns:

the bean instance to use, either the original or a wrapped one; if null, no subsequent BeanPostProcessors will be invoked

See Also:

InitializingBean.afterPropertiesSet()

postProcessAfterInitialization

public Object postProcessAfterInitialization(@Nullable
                                             Object bean,
                                             String beanName)

Create a proxy with the configured interceptors if the bean is identified as one to proxy by the subclass.

Specified by:

postProcessAfterInitialization in interface BeanPostProcessor

Parameters:

bean - the new bean instance

beanName - the name of the bean

Returns:

the bean instance to use, either the original or a wrapped one; if null, no subsequent BeanPostProcessors will be invoked

See Also:

getAdvicesAndAdvisorsForBean(java.lang.Class<?>, java.lang.String, org.springframework.aop.TargetSource)

getCacheKey

protected Object getCacheKey(Class<?> beanClass,
                             @Nullable
                             String beanName)

Build a cache key for the given bean class and bean name.

Note: As of 4.2.3, this implementation does not return a concatenated class/name String anymore but rather the most efficient cache key possible: a plain bean name, prepended with BeanFactory.FACTORY_BEAN_PREFIX in case of a FactoryBean; or if no bean name specified, then the given bean Class as-is.

Parameters:

beanClass - the bean class

beanName - the bean name

Returns:

the cache key for the given class and name

wrapIfNecessary

protected Object wrapIfNecessary(Object bean,
                                 String beanName,
                                 Object cacheKey)

Wrap the given bean if necessary, i.e. if it is eligible for being proxied.

Parameters:

bean - the raw bean instance

beanName - the name of the bean

cacheKey - the cache key for metadata access

Returns:

a proxy wrapping the bean, or the raw bean instance as-is

isInfrastructureClass

protected boolean isInfrastructureClass(Class<?> beanClass)

Return whether the given bean class represents an infrastructure class that should never be proxied.

The default implementation considers Advices, Advisors and AopInfrastructureBeans as infrastructure classes.

Parameters:

beanClass - the class of the bean

Returns:

whether the bean represents an infrastructure class

See Also:

Advice, Advisor, AopInfrastructureBean, shouldSkip(java.lang.Class<?>, java.lang.String)

shouldSkip

protected boolean shouldSkip(Class<?> beanClass,
                             String beanName)

Subclasses should override this method to return true if the given bean should not be considered for auto-proxying by this post-processor.

Sometimes we need to be able to avoid this happening, e.g. if it will lead to a circular reference or if the existing target instance needs to be preserved. This implementation returns false unless the bean name indicates an "original instance" according to AutowireCapableBeanFactory conventions.

Parameters:

beanClass - the class of the bean

beanName - the name of the bean

Returns:

whether to skip the given bean

See Also:

AutowireCapableBeanFactory.ORIGINAL_INSTANCE_SUFFIX

getCustomTargetSource

@Nullable
protected TargetSource getCustomTargetSource(Class<?> beanClass,
                                                       String beanName)

Create a target source for bean instances. Uses any TargetSourceCreators if set. Returns null if no custom TargetSource should be used.

This implementation uses the "customTargetSourceCreators" property. Subclasses can override this method to use a different mechanism.

Parameters:

beanClass - the class of the bean to create a TargetSource for

beanName - the name of the bean

Returns:

a TargetSource for this bean

See Also:

setCustomTargetSourceCreators(org.springframework.aop.framework.autoproxy.TargetSourceCreator...)

createProxy

protected Object createProxy(Class<?> beanClass,
                             @Nullable
                             String beanName,
                             @Nullable
                             Object[] specificInterceptors,
                             TargetSource targetSource)

Create an AOP proxy for the given bean.

Parameters:

beanClass - the class of the bean

beanName - the name of the bean

specificInterceptors - the set of interceptors that is specific to this bean (may be empty, but not null)

targetSource - the TargetSource for the proxy, already pre-configured to access the bean

Returns:

the AOP proxy for the bean

See Also:

buildAdvisors(java.lang.String, java.lang.Object[])

shouldProxyTargetClass

protected boolean shouldProxyTargetClass(Class<?> beanClass,
                                         @Nullable
                                         String beanName)

Determine whether the given bean should be proxied with its target class rather than its interfaces.

Checks the "preserveTargetClass" attribute of the corresponding bean definition.

Parameters:

beanClass - the class of the bean

beanName - the name of the bean

Returns:

whether the given bean should be proxied with its target class

See Also:

AutoProxyUtils.shouldProxyTargetClass(org.springframework.beans.factory.config.ConfigurableListableBeanFactory, java.lang.String)

advisorsPreFiltered

protected boolean advisorsPreFiltered()

Return whether the Advisors returned by the subclass are pre-filtered to match the bean's target class already, allowing the ClassFilter check to be skipped when building advisors chains for AOP invocations.

Default is false. Subclasses may override this if they will always return pre-filtered Advisors.

Returns:

whether the Advisors are pre-filtered

See Also:

getAdvicesAndAdvisorsForBean(java.lang.Class<?>, java.lang.String, org.springframework.aop.TargetSource), Advised.setPreFiltered(boolean)

buildAdvisors

protected Advisor[] buildAdvisors(@Nullable
                                  String beanName,
                                  @Nullable
                                  Object[] specificInterceptors)

Determine the advisors for the given bean, including the specific interceptors as well as the common interceptor, all adapted to the Advisor interface.

Parameters:

beanName - the name of the bean

specificInterceptors - the set of interceptors that is specific to this bean (may be empty, but not null)

Returns:

the list of Advisors for the given bean

customizeProxyFactory

protected void customizeProxyFactory(ProxyFactory proxyFactory)

Subclasses may choose to implement this: for example, to change the interfaces exposed.

The default implementation is empty.

Parameters:

proxyFactory - a ProxyFactory that is already configured with TargetSource and interfaces and will be used to create the proxy immediately after this method returns

getAdvicesAndAdvisorsForBean

@Nullable
protected abstract Object[] getAdvicesAndAdvisorsForBean(Class<?> beanClass,
                                                                   String beanName,
                                                                   @Nullable
                                                                   TargetSource customTargetSource)
                                                            throws BeansException

Return whether the given bean is to be proxied, what additional advices (e.g. AOP Alliance interceptors) and advisors to apply.

Parameters:

beanClass - the class of the bean to advise

beanName - the name of the bean

customTargetSource - the TargetSource returned by the getCustomTargetSource(java.lang.Class<?>, java.lang.String) method: may be ignored. Will be null if no custom target source is in use.

Returns:

an array of additional interceptors for the particular bean; or an empty array if no additional interceptors but just the common ones; or null if no proxy at all, not even with the common interceptors. See constants DO_NOT_PROXY and PROXY_WITHOUT_ADDITIONAL_INTERCEPTORS.

Throws:

BeansException - in case of errors

See Also:

DO_NOT_PROXY, PROXY_WITHOUT_ADDITIONAL_INTERCEPTORS