org.springframework.context.annotation

Class ConfigurationClassEnhancer.BeanMethodInterceptor

java.lang.Object

org.springframework.context.annotation.ConfigurationClassEnhancer.BeanMethodInterceptor

Enclosing class:

ConfigurationClassEnhancer

private static class ConfigurationClassEnhancer.BeanMethodInterceptor
extends java.lang.Object

Intercepts the invocation of any Bean-annotated methods in order to ensure proper handling of bean semantics such as scoping and AOP proxying.

See Also:

Bean, ConfigurationClassEnhancer

Field Summary

Fields

Modifier and Type	Field and Description
private ConfigurableBeanFactory	beanFactory
private static CallbackFilter	CALLBACK_FITLER
private static java.lang.Class<?>[]	CALLBACK_TYPES

Constructor Summary

Constructors

Constructor and Description
ConfigurationClassEnhancer.BeanMethodInterceptor(ConfigurableBeanFactory beanFactory)

Method Summary

Methods

Modifier and Type	Method and Description
private java.lang.Object	enhanceFactoryBean(java.lang.Class<?> fbClass, java.lang.String beanName) Create a subclass proxy that intercepts calls to getObject(), delegating to the current BeanFactory instead of creating a new instance.
private boolean	factoryContainsBean(java.lang.String beanName) Check the beanFactory to see whether the bean named beanName already exists.
java.lang.Object	intercept(java.lang.Object enhancedConfigInstance, java.lang.reflect.Method beanMethod, java.lang.Object[] beanMethodArgs, MethodProxy cglibMethodProxy) Enhance a @Bean method to check the supplied BeanFactory for the existence of this bean object.

Methods inherited from class java.lang.Object

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

Field Detail

CALLBACK_TYPES

private static final java.lang.Class<?>[] CALLBACK_TYPES

CALLBACK_FITLER

private static final CallbackFilter CALLBACK_FITLER

beanFactory

private final ConfigurableBeanFactory beanFactory

Constructor Detail

ConfigurationClassEnhancer.BeanMethodInterceptor

public ConfigurationClassEnhancer.BeanMethodInterceptor(ConfigurableBeanFactory beanFactory)

Method Detail

intercept

public java.lang.Object intercept(java.lang.Object enhancedConfigInstance,
                         java.lang.reflect.Method beanMethod,
                         java.lang.Object[] beanMethodArgs,
                         MethodProxy cglibMethodProxy)
                           throws java.lang.Throwable

Enhance a @Bean method to check the supplied BeanFactory for the existence of this bean object.

Throws:

java.lang.Throwable - as a catch-all for any exception that may be thrown when invoking the super implementation of the proxied method i.e., the actual @Bean method.

factoryContainsBean

private boolean factoryContainsBean(java.lang.String beanName)

Check the beanFactory to see whether the bean named beanName already exists. Accounts for the fact that the requested bean may be "in creation", i.e.: we're in the middle of servicing the initial request for this bean. From an enhanced factory method's perspective, this means that the bean does not actually yet exist, and that it is now our job to create it for the first time by executing the logic in the corresponding factory method.

Said another way, this check repurposes ConfigurableBeanFactory.isCurrentlyInCreation(String) to determine whether the container is calling this method or the user is calling this method.

Parameters:

beanName - name of bean to check for

Returns:

whether beanName already exists in the factory

enhanceFactoryBean

private java.lang.Object enhanceFactoryBean(java.lang.Class<?> fbClass,
                                  java.lang.String beanName)
                                     throws java.lang.InstantiationException,
                                            java.lang.IllegalAccessException

Create a subclass proxy that intercepts calls to getObject(), delegating to the current BeanFactory instead of creating a new instance. These proxies are created only when calling a FactoryBean from within a Bean method, allowing for proper scoping semantics even when working against the FactoryBean instance directly. If a FactoryBean instance is fetched through the container via &-dereferencing, it will not be proxied. This too is aligned with the way XML configuration works.

Throws:

java.lang.InstantiationException

java.lang.IllegalAccessException