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package org.springframework.beans.factory.config;

import org.springframework.beans.BeansException;
import org.springframework.lang.Nullable;

Factory hook that allows for custom modification of new bean instances, e.g. checking for marker interfaces or wrapping them with proxies.

ApplicationContexts can autodetect BeanPostProcessor beans in their bean definitions and apply them to any beans subsequently created. Plain bean factories allow for programmatic registration of post-processors, applying to all beans created through this factory.

Typically, post-processors that populate beans via marker interfaces or the like will implement postProcessBeforeInitialization, while post-processors that wrap beans with proxies will normally implement postProcessAfterInitialization.

Author:Juergen Hoeller
See Also:
Since:10.10.2003
/** * Factory hook that allows for custom modification of new bean instances, * e.g. checking for marker interfaces or wrapping them with proxies. * * <p>ApplicationContexts can autodetect BeanPostProcessor beans in their * bean definitions and apply them to any beans subsequently created. * Plain bean factories allow for programmatic registration of post-processors, * applying to all beans created through this factory. * * <p>Typically, post-processors that populate beans via marker interfaces * or the like will implement {@link #postProcessBeforeInitialization}, * while post-processors that wrap beans with proxies will normally * implement {@link #postProcessAfterInitialization}. * * @author Juergen Hoeller * @since 10.10.2003 * @see InstantiationAwareBeanPostProcessor * @see DestructionAwareBeanPostProcessor * @see ConfigurableBeanFactory#addBeanPostProcessor * @see BeanFactoryPostProcessor */
public 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.

Params:
  • bean – the new bean instance
  • beanName – the name of the bean
Throws:
See Also:
Returns:the bean instance to use, either the original or a wrapped one; if null, no subsequent BeanPostProcessors will be invoked
/** * Apply this BeanPostProcessor to the given new bean instance <i>before</i> any bean * initialization callbacks (like InitializingBean's {@code 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. * <p>The default implementation returns the given {@code bean} as-is. * @param bean the new bean instance * @param beanName the name of the bean * @return the bean instance to use, either the original or a wrapped one; * if {@code null}, no subsequent BeanPostProcessors will be invoked * @throws org.springframework.beans.BeansException in case of errors * @see org.springframework.beans.factory.InitializingBean#afterPropertiesSet */
@Nullable default Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException { return bean; }
Apply this BeanPostProcessor to the given new bean instance after 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.

In case of a FactoryBean, this callback will be invoked for both the FactoryBean instance and the objects created by the FactoryBean (as of Spring 2.0). The post-processor can decide whether to apply to either the FactoryBean or created objects or both through corresponding bean instanceof FactoryBean checks.

This callback will also be invoked after a short-circuiting triggered by a InstantiationAwareBeanPostProcessor.postProcessBeforeInstantiation method, in contrast to all other BeanPostProcessor callbacks.

The default implementation returns the given bean as-is.

Params:
  • bean – the new bean instance
  • beanName – the name of the bean
Throws:
See Also:
Returns:the bean instance to use, either the original or a wrapped one; if null, no subsequent BeanPostProcessors will be invoked
/** * Apply this BeanPostProcessor to the given new bean instance <i>after</i> any bean * initialization callbacks (like InitializingBean's {@code 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. * <p>In case of a FactoryBean, this callback will be invoked for both the FactoryBean * instance and the objects created by the FactoryBean (as of Spring 2.0). The * post-processor can decide whether to apply to either the FactoryBean or created * objects or both through corresponding {@code bean instanceof FactoryBean} checks. * <p>This callback will also be invoked after a short-circuiting triggered by a * {@link InstantiationAwareBeanPostProcessor#postProcessBeforeInstantiation} method, * in contrast to all other BeanPostProcessor callbacks. * <p>The default implementation returns the given {@code bean} as-is. * @param bean the new bean instance * @param beanName the name of the bean * @return the bean instance to use, either the original or a wrapped one; * if {@code null}, no subsequent BeanPostProcessors will be invoked * @throws org.springframework.beans.BeansException in case of errors * @see org.springframework.beans.factory.InitializingBean#afterPropertiesSet * @see org.springframework.beans.factory.FactoryBean */
@Nullable default Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException { return bean; } }