org.springframework.aop.framework.autoproxy
Class AbstractAutoProxyCreator

java.lang.Object
  org.springframework.aop.framework.ProxyConfig
      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 ProxyConfig
implements SmartInstantiationAwareBeanPostProcessor, BeanClassLoaderAware, BeanFactoryAware, Ordered, AopInfrastructureBean

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. The default concrete implementation is BeanNameAutoProxyCreator, identifying the beans to be proxied via a list of bean 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

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

AbstractAutoProxyCreator()

Method Summary

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.
int	getOrder() Return the order value of this object, with a higher value meaning greater in terms of sorting.
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	postProcessPropertyValues(PropertyValues pvs, PropertyDescriptor[] pds, Object bean, String beanName) Post-process the given property values before the factory applies them to the given bean.
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	setBeanClassLoader(ClassLoader classLoader) Callback that supplies the bean class loader to a bean instance.
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.
void	setOrder(int order) Set the ordering which will apply to this class's implementation of Ordered, used when applying multiple BeanPostProcessors.
void	setProxyClassLoader(ClassLoader classLoader) Set the ClassLoader to generate the proxy class in.
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.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

Field Detail

DO_NOT_PROXY

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

setOrder

public final void setOrder(int order)

Set the ordering which will apply to this class's implementation of Ordered, used when applying multiple BeanPostProcessors.

Default value is Integer.MAX_VALUE, meaning that it's non-ordered.

Parameters:

order - ordering value

getOrder

public final 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, 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).

Specified by:

getOrder in interface Ordered

Returns:

the order value

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 used.

Parameters:

targetSourceCreators - list of TargetSourceCreator. 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.

setProxyClassLoader

public void setProxyClassLoader(ClassLoader classLoader)

Set the ClassLoader to generate the proxy class in.

Default is the bean ClassLoader, i.e. the ClassLoader used by the containing BeanFactory for loading all bean classes. This can be overridden here for specific proxies.

setBeanClassLoader

public void setBeanClassLoader(ClassLoader classLoader)

Description copied from interface: BeanClassLoaderAware

Callback that supplies the bean class loader to a bean instance.

Invoked after the population of normal bean properties but before an initialization callback such as InitializingBean's InitializingBean.afterPropertiesSet() method or a custom init-method.

Specified by:

setBeanClassLoader in interface BeanClassLoaderAware

Parameters:

classLoader - the owning class loader; may be null in which case a default ClassLoader must be used, for example the ClassLoader obtained via ClassUtils.getDefaultClassLoader()

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

protected BeanFactory getBeanFactory()

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

predictBeanType

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.

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

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

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

Throws:

BeansException - in case of errors

getEarlyBeanReference

public Object getEarlyBeanReference(Object bean,
                                    String beanName)
                             throws BeansException

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).

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)

Throws:

BeansException - in case of errors

postProcessBeforeInstantiation

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

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 only be applied to bean definitions with a bean class. In particular, it will not be applied to beans with a "factory-method".

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.

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

Throws:

BeansException - in case of errors

See Also:

AbstractBeanDefinition.hasBeanClass(), 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 field injection on the given bean instance. See Spring's own AutowiredAnnotationBeanPostProcessor for a typical example.

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.

postProcessPropertyValues

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

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

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

See Also:

MutablePropertyValues

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.

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(Object bean,
                                             String beanName)
                                      throws BeansException

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

Throws:

BeansException - in case of errors

See Also:

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

getCacheKey

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

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

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.

Default implementation considers Advisors, Advices and AbstractAutoProxyCreators as infrastructure classes.

Parameters:

beanClass - the class of the bean

Returns:

whether the bean represents an infrastructure class

See Also:

Advisor, MethodInterceptor, 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 if it will lead to a circular reference. This implementation returns false.

Parameters:

beanClass - the class of the bean

beanName - the name of the bean

Returns:

whether to skip the given bean

getCustomTargetSource

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,
                             String beanName,
                             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,
                                         String beanName)

Determine whether the given bean should be proxied with its target class rather than its interfaces. Checks the "proxyTargetClass" setting as well as 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(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.

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

getAdvicesAndAdvisorsForBean

protected abstract Object[] getAdvicesAndAdvisorsForBean(Class<?> beanClass,
                                                         String beanName,
                                                         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