/*
* Copyright 2002-2014 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;
/**
* Callback interface triggered at the end of the singleton pre-instantiation phase
* during {@link BeanFactory} bootstrap. This interface can be implemented by
* singleton beans in order to perform some initialization after the regular
* singleton instantiation algorithm, avoiding side effects with accidental early
* initialization (e.g. from {@link ListableBeanFactory#getBeansOfType} calls).
* In that sense, it is an alternative to {@link InitializingBean} which gets
* triggered right at the end of a bean's local construction phase.
*
* <p>This callback variant is somewhat similar to
* {@link org.springframework.context.event.ContextRefreshedEvent} but doesn't
* require an implementation of {@link org.springframework.context.ApplicationListener},
* with no need to filter context references across a context hierarchy etc.
* It also implies a more minimal dependency on just the {@code beans} package
* and is being honored by standalone {@link ListableBeanFactory} implementations,
* not just in an {@link org.springframework.context.ApplicationContext} environment.
*
* <p><b>NOTE:</b> If you intend to start/manage asynchronous tasks, preferably
* implement {@link org.springframework.context.Lifecycle} instead which offers
* a richer model for runtime management and allows for phased startup/shutdown.
*
* @author Juergen Hoeller
* @since 4.1
* @see org.springframework.beans.factory.config.ConfigurableListableBeanFactory#preInstantiateSingletons()
*/
public interface SmartInitializingSingleton {
/**
* Invoked right at the end of the singleton pre-instantiation phase,
* with a guarantee that all regular singleton beans have been created
* already. {@link ListableBeanFactory#getBeansOfType} calls within
* this method won't trigger accidental side effects during bootstrap.
* <p><b>NOTE:</b> This callback won't be triggered for singleton beans
* lazily initialized on demand after {@link BeanFactory} bootstrap,
* and not for any other bean scope either. Carefully use it for beans
* with the intended bootstrap semantics only.
*/
void afterSingletonsInstantiated();
}