org.springframework.aop.framework

Class AbstractSingletonProxyFactoryBean

java.lang.Object

org.springframework.aop.framework.ProxyConfig

org.springframework.aop.framework.AbstractSingletonProxyFactoryBean

All Implemented Interfaces:

java.io.Serializable, Aware, BeanClassLoaderAware, FactoryBean<java.lang.Object>, InitializingBean

Direct Known Subclasses:

CacheProxyFactoryBean, TransactionProxyFactoryBean

public abstract class AbstractSingletonProxyFactoryBean
extends ProxyConfig
implements FactoryBean<java.lang.Object>, BeanClassLoaderAware, InitializingBean

Convenient superclass for FactoryBean types that produce singleton-scoped proxy objects.

Manages pre- and post-interceptors (references, rather than interceptor names, as in ProxyFactoryBean) and provides consistent interface management.

Since:

2.0

Author:

Juergen Hoeller

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
private AdvisorAdapterRegistry	advisorAdapterRegistry Default is global AdvisorAdapterRegistry
private java.lang.Object[]	postInterceptors
private java.lang.Object[]	preInterceptors
private java.lang.Object	proxy
private java.lang.ClassLoader	proxyClassLoader
private java.lang.Class<?>[]	proxyInterfaces
private java.lang.Object	target

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

exposeProxy, opaque

Constructor Summary

Constructors

Constructor and Description
AbstractSingletonProxyFactoryBean()

Method Summary

Modifier and Type	Method and Description
void	afterPropertiesSet() Invoked by a BeanFactory after it has set all bean properties supplied (and satisfied BeanFactoryAware and ApplicationContextAware).
protected abstract java.lang.Object	createMainInterceptor() Create the "main" interceptor for this proxy factory bean.
protected TargetSource	createTargetSource(java.lang.Object target) Determine a TargetSource for the given target (or TargetSource).
java.lang.Object	getObject() Return an instance (possibly shared or independent) of the object managed by this factory.
java.lang.Class<?>	getObjectType() Return the type of object that this FactoryBean creates, or null if not known in advance.
boolean	isSingleton() Is the object managed by this factory a singleton? That is, will FactoryBean.getObject() always return the same object (a reference that can be cached)?
protected void	postProcessProxyFactory(ProxyFactory proxyFactory) A hook for subclasses to post-process the ProxyFactory before creating the proxy instance with it.
void	setAdvisorAdapterRegistry(AdvisorAdapterRegistry advisorAdapterRegistry) Specify the AdvisorAdapterRegistry to use.
void	setBeanClassLoader(java.lang.ClassLoader classLoader) Callback that supplies the bean class loader to a bean instance.
void	setPostInterceptors(java.lang.Object[] postInterceptors) Set additional interceptors (or advisors) to be applied after the implicit transaction interceptor.
void	setPreInterceptors(java.lang.Object[] preInterceptors) Set additional interceptors (or advisors) to be applied before the implicit transaction interceptor, e.g.
void	setProxyClassLoader(java.lang.ClassLoader classLoader) Set the ClassLoader to generate the proxy class in.
void	setProxyInterfaces(java.lang.Class<?>[] proxyInterfaces) Specify the set of interfaces being proxied.
void	setTarget(java.lang.Object target) Set the target object, that is, the bean to be wrapped with a transactional proxy.

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

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

Methods inherited from class java.lang.Object

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

Field Detail

target

private java.lang.Object target

proxyInterfaces

private java.lang.Class<?>[] proxyInterfaces

preInterceptors

private java.lang.Object[] preInterceptors

postInterceptors

private java.lang.Object[] postInterceptors

advisorAdapterRegistry

private AdvisorAdapterRegistry advisorAdapterRegistry

Default is global AdvisorAdapterRegistry

proxyClassLoader

private transient java.lang.ClassLoader proxyClassLoader

proxy

private java.lang.Object proxy

Constructor Detail

AbstractSingletonProxyFactoryBean

public AbstractSingletonProxyFactoryBean()

Method Detail

setTarget

public void setTarget(java.lang.Object target)

Set the target object, that is, the bean to be wrapped with a transactional proxy.

The target may be any object, in which case a SingletonTargetSource will be created. If it is a TargetSource, no wrapper TargetSource is created: This enables the use of a pooling or prototype TargetSource etc.

See Also:

TargetSource, SingletonTargetSource, LazyInitTargetSource, PrototypeTargetSource, CommonsPool2TargetSource

setProxyInterfaces

public void setProxyInterfaces(java.lang.Class<?>[] proxyInterfaces)

Specify the set of interfaces being proxied.

If not specified (the default), the AOP infrastructure works out which interfaces need proxying by analyzing the target, proxying all the interfaces that the target object implements.

setPreInterceptors

public void setPreInterceptors(java.lang.Object[] preInterceptors)

Set additional interceptors (or advisors) to be applied before the implicit transaction interceptor, e.g. a PerformanceMonitorInterceptor.

You may specify any AOP Alliance MethodInterceptors or other Spring AOP Advices, as well as Spring AOP Advisors.

See Also:

PerformanceMonitorInterceptor

setPostInterceptors

public void setPostInterceptors(java.lang.Object[] postInterceptors)

Set additional interceptors (or advisors) to be applied after the implicit transaction interceptor.

You may specify any AOP Alliance MethodInterceptors or other Spring AOP Advices, as well as Spring AOP Advisors.

setAdvisorAdapterRegistry

public void setAdvisorAdapterRegistry(AdvisorAdapterRegistry advisorAdapterRegistry)

Specify the AdvisorAdapterRegistry to use. Default is the global AdvisorAdapterRegistry.

See Also:

GlobalAdvisorAdapterRegistry

setProxyClassLoader

public void setProxyClassLoader(java.lang.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(java.lang.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()

afterPropertiesSet

public void afterPropertiesSet()

Description copied from interface: InitializingBean

Invoked by a BeanFactory after it has set all bean properties supplied (and satisfied BeanFactoryAware and ApplicationContextAware).

This method allows the bean instance to perform initialization only possible when all bean properties have been set and to throw an exception in the event of misconfiguration.

Specified by:

afterPropertiesSet in interface InitializingBean

createTargetSource

protected TargetSource createTargetSource(java.lang.Object target)

Determine a TargetSource for the given target (or TargetSource).

Parameters:

target - target. If this is an implementation of TargetSource it is used as our TargetSource; otherwise it is wrapped in a SingletonTargetSource.

Returns:

a TargetSource for this object

postProcessProxyFactory

protected void postProcessProxyFactory(ProxyFactory proxyFactory)

A hook for subclasses to post-process the ProxyFactory before creating the proxy instance with it.

Parameters:

proxyFactory - the AOP ProxyFactory about to be used

Since:

4.2

getObject

public java.lang.Object getObject()

Description copied from interface: FactoryBean

Return an instance (possibly shared or independent) of the object managed by this factory.

As with a BeanFactory, this allows support for both the Singleton and Prototype design pattern.

If this FactoryBean is not fully initialized yet at the time of the call (for example because it is involved in a circular reference), throw a corresponding FactoryBeanNotInitializedException.

As of Spring 2.0, FactoryBeans are allowed to return null objects. The factory will consider this as normal value to be used; it will not throw a FactoryBeanNotInitializedException in this case anymore. FactoryBean implementations are encouraged to throw FactoryBeanNotInitializedException themselves now, as appropriate.

Specified by:

getObject in interface FactoryBean<java.lang.Object>

Returns:

an instance of the bean (can be null)

See Also:

FactoryBeanNotInitializedException

getObjectType

public java.lang.Class<?> getObjectType()

Description copied from interface: FactoryBean

Return the type of object that this FactoryBean creates, or null if not known in advance.

This allows one to check for specific types of beans without instantiating objects, for example on autowiring.

In the case of implementations that are creating a singleton object, this method should try to avoid singleton creation as far as possible; it should rather estimate the type in advance. For prototypes, returning a meaningful type here is advisable too.

This method can be called before this FactoryBean has been fully initialized. It must not rely on state created during initialization; of course, it can still use such state if available.

NOTE: Autowiring will simply ignore FactoryBeans that return null here. Therefore it is highly recommended to implement this method properly, using the current state of the FactoryBean.

Specified by:

getObjectType in interface FactoryBean<java.lang.Object>

Returns:

the type of object that this FactoryBean creates, or null if not known at the time of the call

See Also:

ListableBeanFactory.getBeansOfType(java.lang.Class<T>)

isSingleton

public final boolean isSingleton()

Description copied from interface: FactoryBean

Is the object managed by this factory a singleton? That is, will FactoryBean.getObject() always return the same object (a reference that can be cached)?

NOTE: If a FactoryBean indicates to hold a singleton object, the object returned from getObject() might get cached by the owning BeanFactory. Hence, do not return true unless the FactoryBean always exposes the same reference.

The singleton status of the FactoryBean itself will generally be provided by the owning BeanFactory; usually, it has to be defined as singleton there.

NOTE: This method returning false does not necessarily indicate that returned objects are independent instances. An implementation of the extended SmartFactoryBean interface may explicitly indicate independent instances through its SmartFactoryBean.isPrototype() method. Plain FactoryBean implementations which do not implement this extended interface are simply assumed to always return independent instances if the isSingleton() implementation returns false.

Specified by:

isSingleton in interface FactoryBean<java.lang.Object>

Returns:

whether the exposed object is a singleton

See Also:

FactoryBean.getObject(), SmartFactoryBean.isPrototype()

createMainInterceptor

protected abstract java.lang.Object createMainInterceptor()

Create the "main" interceptor for this proxy factory bean. Typically an Advisor, but can also be any type of Advice.

Pre-interceptors will be applied before, post-interceptors will be applied after this interceptor.