/*
* Copyright 2002-2007 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;
/**
* Interface that defines a registry for shared bean instances.
* Can be implemented by {@link org.springframework.beans.factory.BeanFactory}
* implementations in order to expose their singleton management facility
* in a uniform manner.
*
* <p>The {@link ConfigurableBeanFactory} interface extends this interface.
*
* @author Juergen Hoeller
* @since 2.0
* @see ConfigurableBeanFactory
* @see org.springframework.beans.factory.support.DefaultSingletonBeanRegistry
* @see org.springframework.beans.factory.support.AbstractBeanFactory
*/
public interface SingletonBeanRegistry {
/**
* Register the given existing object as singleton in the bean registry,
* under the given bean name.
* <p>The given instance is supposed to be fully initialized; the registry
* will not perform any initialization callbacks (in particular, it won't
* call InitializingBean's <code>afterPropertiesSet</code> method).
* The given instance will not receive any destruction callbacks
* (like DisposableBean's <code>destroy</code> method) either.
* <p>If running within a full BeanFactory: <b>Register a bean definition
* instead of an existing instance if your bean is supposed to receive
* initialization and/or destruction callbacks.</b>
* <p>Typically invoked during registry configuration, but can also be used
* for runtime registration of singletons. As a consequence, a registry
* implementation should synchronize singleton access; it will have to do
* this anyway if it supports a BeanFactory's lazy initialization of singletons.
* @param beanName the name of the bean
* @param singletonObject the existing singleton object
* @see org.springframework.beans.factory.InitializingBean#afterPropertiesSet
* @see org.springframework.beans.factory.DisposableBean#destroy
* @see org.springframework.beans.factory.support.BeanDefinitionRegistry#registerBeanDefinition
*/
void registerSingleton(String beanName, Object singletonObject);
/**
* Return the (raw) singleton object registered under the given name.
* <p>Only checks already instantiated singletons; does not return an Object
* for singleton bean definitions which have not been instantiated yet.
* <p>The main purpose of this method is to access manually registered singletons
* (see {@link #registerSingleton}). Can also be used to access a singleton
* defined by a bean definition that already been created, in a raw fashion.
* @param beanName the name of the bean to look for
* @return the registered singleton object, or <code>null</code> if none found
* @see ConfigurableListableBeanFactory#getBeanDefinition
*/
Object getSingleton(String beanName);
/**
* Check if this registry contains a singleton instance with the given name.
* <p>Only checks already instantiated singletons; does not return <code>true</code>
* for singleton bean definitions which have not been instantiated yet.
* <p>The main purpose of this method is to check manually registered singletons
* (see {@link #registerSingleton}). Can also be used to check whether a
* singleton defined by a bean definition has already been created.
* <p>To check whether a bean factory contains a bean definition with a given name,
* use ListableBeanFactory's <code>containsBeanDefinition</code>. Calling both
* <code>containsBeanDefinition</code> and <code>containsSingleton</code> answers
* whether a specific bean factory contains an own bean with the given name.
* <p>Use BeanFactory's <code>containsBean</code> for general checks whether the
* factory knows about a bean with a given name (whether manually registered singleton
* instance or created by bean definition), also checking ancestor factories.
* @param beanName the name of the bean to look for
* @return if this bean factory contains a singleton instance with the given name
* @see #registerSingleton
* @see org.springframework.beans.factory.ListableBeanFactory#containsBeanDefinition
* @see org.springframework.beans.factory.BeanFactory#containsBean
*/
boolean containsSingleton(String beanName);
/**
* Return the names of singleton beans registered in this registry.
* <p>Only checks already instantiated singletons; does not return names
* for singleton bean definitions which have not been instantiated yet.
* <p>The main purpose of this method is to check manually registered singletons
* (see {@link #registerSingleton}). Can also be used to check which
* singletons defined by a bean definition have already been created.
* @return the list of names as String array (never <code>null</code>)
* @see #registerSingleton
* @see org.springframework.beans.factory.support.BeanDefinitionRegistry#getBeanDefinitionNames
* @see org.springframework.beans.factory.ListableBeanFactory#getBeanDefinitionNames
*/
String[] getSingletonNames();
/**
* Return the number of singleton beans registered in this registry.
* <p>Only checks already instantiated singletons; does not count
* singleton bean definitions which have not been instantiated yet.
* <p>The main purpose of this method is to check manually registered singletons
* (see {@link #registerSingleton}). Can also be used to count the number of
* singletons defined by a bean definition that have already been created.
* @return the number of singleton beans
* @see #registerSingleton
* @see org.springframework.beans.factory.support.BeanDefinitionRegistry#getBeanDefinitionCount
* @see org.springframework.beans.factory.ListableBeanFactory#getBeanDefinitionCount
*/
int getSingletonCount();
}