1   /*
    2    * Copyright 2002-2007 the original author or authors.
    3    *
    4    * Licensed under the Apache License, Version 2.0 (the "License");
    5    * you may not use this file except in compliance with the License.
    6    * You may obtain a copy of the License at
    7    *
    8    *      http://www.apache.org/licenses/LICENSE-2.0
    9    *
   10    * Unless required by applicable law or agreed to in writing, software
   11    * distributed under the License is distributed on an "AS IS" BASIS,
   12    * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   13    * See the License for the specific language governing permissions and
   14    * limitations under the License.
   15    */
   16   
   17   package org.springframework.beans.factory;
   18   
   19   /**
   20    * Extension of the {@link FactoryBean} interface. Implementations may
   21    * indicate whether they always return independent instances, for the
   22    * case where their {@link #isSingleton()} implementation returning
   23    * <code>false</code> does not clearly indicate independent instances.
   24    *
   25    * <p>Plain {@link FactoryBean} implementations which do not implement
   26    * this extended interface are simply assumed to always return independent
   27    * instances if their {@link #isSingleton()} implementation returns
   28    * <code>false</code>; the exposed object is only accessed on demand.
   29    *
   30    * <p><b>NOTE:</b> This interface is a special purpose interface, mainly for
   31    * internal use within the framework and within collaborating frameworks.
   32    * In general, application-provided FactoryBeans should simply implement
   33    * the plain {@link FactoryBean} interface. New methods might be added
   34    * to this extended interface even in point releases.
   35    *
   36    * @author Juergen Hoeller
   37    * @since 2.0.3
   38    * @see #isPrototype()
   39    * @see #isSingleton()
   40    */
   41   public interface SmartFactoryBean extends FactoryBean {
   42   
   43   	/**
   44   	 * Is the object managed by this factory a prototype? That is,
   45   	 * will {@link #getObject()} always return an independent instance?
   46   	 * <p>The prototype status of the FactoryBean itself will generally
   47   	 * be provided by the owning {@link BeanFactory}; usually, it has to be
   48   	 * defined as singleton there.
   49   	 * <p>This method is supposed to strictly check for independent instances;
   50   	 * it should not return <code>true</code> for scoped objects or other
   51   	 * kinds of non-singleton, non-independent objects. For this reason,
   52   	 * this is not simply the inverted form of {@link #isSingleton()}.
   53   	 * @return whether the exposed object is a prototype
   54   	 * @see #getObject()
   55   	 * @see #isSingleton()
   56   	 */
   57   	boolean isPrototype();
   58   
   59   	/**
   60   	 * Does this FactoryBean expect eager initialization, that is,
   61   	 * eagerly initialize itself as well as expect eager initialization
   62   	 * of its singleton object (if any)?
   63   	 * <p>A standard FactoryBean is not expected to initialize eagerly:
   64   	 * Its {@link #getObject()} will only be called for actual access, even
   65   	 * in case of a singleton object. Returning <code>true</code> from this
   66   	 * method suggests that {@link #getObject()} should be called eagerly,
   67   	 * also applying post-processors eagerly. This may make sense in case
   68   	 * of a {@link #isSingleton() singleton} object, in particular if
   69   	 * post-processors expect to be applied on startup.
   70   	 * @return whether eager initialization applies
   71   	 * @see org.springframework.beans.factory.config.ConfigurableListableBeanFactory#preInstantiateSingletons()
   72   	 */
   73   	boolean isEagerInit();
   74   
   75   }