/*
* Copyright 2002-2016 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.beans.factory.config;
import java.lang.reflect.Constructor;
import org.springframework.beans.BeansException;
/**
* Extension of the {@link InstantiationAwareBeanPostProcessor} interface,
* adding a callback for predicting the eventual type of a processed bean.
*
* <p><b>NOTE:</b> This interface is a special purpose interface, mainly for
* internal use within the framework. In general, application-provided
* post-processors should simply implement the plain {@link BeanPostProcessor}
* interface or derive from the {@link InstantiationAwareBeanPostProcessorAdapter}
* class. New methods might be added to this interface even in point releases.
*
* @author Juergen Hoeller
* @since 2.0.3
* @see InstantiationAwareBeanPostProcessorAdapter
*/
public interface SmartInstantiationAwareBeanPostProcessor extends InstantiationAwareBeanPostProcessor {
/**
* Predict the type of the bean to be eventually returned from this
* processor's {@link #postProcessBeforeInstantiation} callback.
* <p>The default implementation returns {@code null}.
* @param beanClass the raw class of the bean
* @param beanName the name of the bean
* @return the type of the bean, or {@code null} if not predictable
* @throws org.springframework.beans.BeansException in case of errors
*/
default Class<?> predictBeanType(Class<?> beanClass, String beanName) throws BeansException {
return null;
}
/**
* Determine the candidate constructors to use for the given bean.
* <p>The default implementation returns {@code null}.
* @param beanClass the raw class of the bean (never {@code null})
* @param beanName the name of the bean
* @return the candidate constructors, or {@code null} if none specified
* @throws org.springframework.beans.BeansException in case of errors
*/
default Constructor<?>[] determineCandidateConstructors(Class<?> beanClass, String beanName)
throws BeansException {
return null;
}
/**
* Obtain a reference for early access to the specified bean,
* typically for the purpose of resolving a circular reference.
* <p>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
* {@link #postProcessBeforeInitialization} / {@link #postProcessAfterInitialization}
* 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).
* <p>The default implementation returns the given {@code bean} as-is.
* @param bean the raw bean instance
* @param beanName the name of the bean
* @return the object to expose as bean reference
* (typically with the passed-in bean instance as default)
* @throws org.springframework.beans.BeansException in case of errors
*/
default Object getEarlyBeanReference(Object bean, String beanName) throws BeansException {
return bean;
}
}