infra.beans.factory.SmartFactoryBean Maven / Gradle / Ivy
/*
* Copyright 2017 - 2024 the original author or authors.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see [https://www.gnu.org/licenses/]
*/
package infra.beans.factory;
import infra.beans.factory.config.ConfigurableBeanFactory;
/**
* Extension of the {@link FactoryBean} interface. Implementations may
* indicate whether they always return independent instances, for the
* case where their is singleton implementation returning {@code false}
* does not clearly indicate independent instances.
*
* Plain {@link FactoryBean} implementations which do not implement
* this extended interface are simply assumed to always return independent
* instances if their is singleton implementation returns {@code false};
* the exposed object is only accessed on demand.
*
*
NOTE: This interface is a special purpose interface, mainly for
* internal use within the framework and within collaborating frameworks.
* In general, application-provided FactoryBeans should simply implement
* the plain {@link FactoryBean} interface. New methods might be added
* to this extended interface even in point releases.
*
* @param the bean type
* @author Juergen Hoeller
* @author TODAY 2021/3/9 14:06
* @since 3.0
*/
public interface SmartFactoryBean extends FactoryBean {
/**
* Is the object managed by this factory a prototype? That is,
* will {@link #getObject()} always return an independent instance?
* The prototype status of the FactoryBean itself will generally
* be provided by the owning {@link BeanFactory}; usually, it has to be
* defined as singleton there.
*
This method is supposed to strictly check for independent instances;
* it should not return {@code true} for scoped objects or other
* kinds of non-singleton, non-independent objects. For this reason,
* this is not simply the inverted form of {@link #isSingleton()}.
*
The default implementation returns {@code false}.
*
* @return whether the exposed object is a prototype
* @see #getObject()
* @see #isSingleton()
* @since 4.0
*/
default boolean isPrototype() {
return false;
}
/**
* Does this FactoryBean expect eager initialization, that is,
* eagerly initialize itself as well as expect eager initialization
* of its singleton object (if any)?
*
A standard FactoryBean is not expected to initialize eagerly:
* Its {@link #getObject()} will only be called for actual access, even
* in case of a singleton object. Returning {@code true} from this
* method suggests that {@link #getObject()} should be called eagerly,
* also applying post-processors eagerly. This may make sense in case
* of a is singleton object, in particular if post-processors expect
* to be applied on startup.
*
The default implementation returns {@code false}.
*
* @return whether eager initialization applies
* @see ConfigurableBeanFactory#preInstantiateSingletons()
*/
default boolean isEagerInit() {
return false;
}
}