Java tutorial
/* * Copyright 2002-2019 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 * * https://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.util.Set; import org.springframework.beans.BeansException; import org.springframework.beans.TypeConverter; import org.springframework.beans.factory.BeanFactory; import org.springframework.beans.factory.NoSuchBeanDefinitionException; import org.springframework.beans.factory.NoUniqueBeanDefinitionException; import org.springframework.lang.Nullable; /** * Extension of the {@link org.springframework.beans.factory.BeanFactory} * interface to be implemented by bean factories that are capable of * autowiring, provided that they want to expose this functionality for * existing bean instances. * * <p>This subinterface of BeanFactory is not meant to be used in normal * application code: stick to {@link org.springframework.beans.factory.BeanFactory} * or {@link org.springframework.beans.factory.ListableBeanFactory} for * typical use cases. * * <p>Integration code for other frameworks can leverage this interface to * wire and populate existing bean instances that Spring does not control * the lifecycle of. This is particularly useful for WebWork Actions and * Tapestry Page objects, for example. * * <p>Note that this interface is not implemented by * {@link org.springframework.context.ApplicationContext} facades, * as it is hardly ever used by application code. That said, it is available * from an application context too, accessible through ApplicationContext's * {@link org.springframework.context.ApplicationContext#getAutowireCapableBeanFactory()} * method. * * <p>You may also implement the {@link org.springframework.beans.factory.BeanFactoryAware} * interface, which exposes the internal BeanFactory even when running in an * ApplicationContext, to get access to an AutowireCapableBeanFactory: * simply cast the passed-in BeanFactory to AutowireCapableBeanFactory. * * @author Juergen Hoeller * @since 04.12.2003 * @see org.springframework.beans.factory.BeanFactoryAware * @see org.springframework.beans.factory.config.ConfigurableListableBeanFactory * @see org.springframework.context.ApplicationContext#getAutowireCapableBeanFactory() */ public interface AutowireCapableBeanFactory extends BeanFactory { /** * Constant that indicates no externally defined autowiring. Note that * BeanFactoryAware etc and annotation-driven injection will still be applied. * @see #createBean * @see #autowire * @see #autowireBeanProperties */ int AUTOWIRE_NO = 0; /** * Constant that indicates autowiring bean properties by name * (applying to all bean property setters). * @see #createBean * @see #autowire * @see #autowireBeanProperties */ int AUTOWIRE_BY_NAME = 1; /** * Constant that indicates autowiring bean properties by type * (applying to all bean property setters). * @see #createBean * @see #autowire * @see #autowireBeanProperties */ int AUTOWIRE_BY_TYPE = 2; /** * Constant that indicates autowiring the greediest constructor that * can be satisfied (involves resolving the appropriate constructor). * @see #createBean * @see #autowire */ int AUTOWIRE_CONSTRUCTOR = 3; /** * Constant that indicates determining an appropriate autowire strategy * through introspection of the bean class. * @see #createBean * @see #autowire * @deprecated as of Spring 3.0: If you are using mixed autowiring strategies, * prefer annotation-based autowiring for clearer demarcation of autowiring needs. */ @Deprecated int AUTOWIRE_AUTODETECT = 4; /** * Suffix for the "original instance" convention when initializing an existing * bean instance: to be appended to the fully-qualified bean class name, * e.g. "com.mypackage.MyClass.ORIGINAL", in order to enforce the given instance * to be returned, i.e. no proxies etc. * @since 5.1 * @see #initializeBean(Object, String) * @see #applyBeanPostProcessorsBeforeInitialization(Object, String) * @see #applyBeanPostProcessorsAfterInitialization(Object, String) */ String ORIGINAL_INSTANCE_SUFFIX = ".ORIGINAL"; //------------------------------------------------------------------------- // Typical methods for creating and populating external bean instances //------------------------------------------------------------------------- /** * Fully create a new bean instance of the given class. * <p>Performs full initialization of the bean, including all applicable * {@link BeanPostProcessor BeanPostProcessors}. * <p>Note: This is intended for creating a fresh instance, populating annotated * fields and methods as well as applying all standard bean initialization callbacks. * It does <i>not</i> imply traditional by-name or by-type autowiring of properties; * use {@link #createBean(Class, int, boolean)} for those purposes. * @param beanClass the class of the bean to create * @return the new bean instance * @throws BeansException if instantiation or wiring failed */ <T> T createBean(Class<T> beanClass) throws BeansException; /** * Populate the given bean instance through applying after-instantiation callbacks * and bean property post-processing (e.g. for annotation-driven injection). * <p>Note: This is essentially intended for (re-)populating annotated fields and * methods, either for new instances or for deserialized instances. It does * <i>not</i> imply traditional by-name or by-type autowiring of properties; * use {@link #autowireBeanProperties} for those purposes. * @param existingBean the existing bean instance * @throws BeansException if wiring failed */ void autowireBean(Object existingBean) throws BeansException; /** * Configure the given raw bean: autowiring bean properties, applying * bean property values, applying factory callbacks such as {@code setBeanName} * and {@code setBeanFactory}, and also applying all bean post processors * (including ones which might wrap the given raw bean). * <p>This is effectively a superset of what {@link #initializeBean} provides, * fully applying the configuration specified by the corresponding bean definition. * <b>Note: This method requires a bean definition for the given name!</b> * @param existingBean the existing bean instance * @param beanName the name of the bean, to be passed to it if necessary * (a bean definition of that name has to be available) * @return the bean instance to use, either the original or a wrapped one * @throws org.springframework.beans.factory.NoSuchBeanDefinitionException * if there is no bean definition with the given name * @throws BeansException if the initialization failed * @see #initializeBean */ Object configureBean(Object existingBean, String beanName) throws BeansException; //------------------------------------------------------------------------- // Specialized methods for fine-grained control over the bean lifecycle //------------------------------------------------------------------------- /** * Fully create a new bean instance of the given class with the specified * autowire strategy. All constants defined in this interface are supported here. * <p>Performs full initialization of the bean, including all applicable * {@link BeanPostProcessor BeanPostProcessors}. This is effectively a superset * of what {@link #autowire} provides, adding {@link #initializeBean} behavior. * @param beanClass the class of the bean to create * @param autowireMode by name or type, using the constants in this interface * @param dependencyCheck whether to perform a dependency check for objects * (not applicable to autowiring a constructor, thus ignored there) * @return the new bean instance * @throws BeansException if instantiation or wiring failed * @see #AUTOWIRE_NO * @see #AUTOWIRE_BY_NAME * @see #AUTOWIRE_BY_TYPE * @see #AUTOWIRE_CONSTRUCTOR */ Object createBean(Class<?> beanClass, int autowireMode, boolean dependencyCheck) throws BeansException; /** * Instantiate a new bean instance of the given class with the specified autowire * strategy. All constants defined in this interface are supported here. * Can also be invoked with {@code AUTOWIRE_NO} in order to just apply * before-instantiation callbacks (e.g. for annotation-driven injection). * <p>Does <i>not</i> apply standard {@link BeanPostProcessor BeanPostProcessors} * callbacks or perform any further initialization of the bean. This interface * offers distinct, fine-grained operations for those purposes, for example * {@link #initializeBean}. However, {@link InstantiationAwareBeanPostProcessor} * callbacks are applied, if applicable to the construction of the instance. * @param beanClass the class of the bean to instantiate * @param autowireMode by name or type, using the constants in this interface * @param dependencyCheck whether to perform a dependency check for object * references in the bean instance (not applicable to autowiring a constructor, * thus ignored there) * @return the new bean instance * @throws BeansException if instantiation or wiring failed * @see #AUTOWIRE_NO * @see #AUTOWIRE_BY_NAME * @see #AUTOWIRE_BY_TYPE * @see #AUTOWIRE_CONSTRUCTOR * @see #AUTOWIRE_AUTODETECT * @see #initializeBean * @see #applyBeanPostProcessorsBeforeInitialization * @see #applyBeanPostProcessorsAfterInitialization */ Object autowire(Class<?> beanClass, int autowireMode, boolean dependencyCheck) throws BeansException; /** * Autowire the bean properties of the given bean instance by name or type. * Can also be invoked with {@code AUTOWIRE_NO} in order to just apply * after-instantiation callbacks (e.g. for annotation-driven injection). * <p>Does <i>not</i> apply standard {@link BeanPostProcessor BeanPostProcessors} * callbacks or perform any further initialization of the bean. This interface * offers distinct, fine-grained operations for those purposes, for example * {@link #initializeBean}. However, {@link InstantiationAwareBeanPostProcessor} * callbacks are applied, if applicable to the configuration of the instance. * @param existingBean the existing bean instance * @param autowireMode by name or type, using the constants in this interface * @param dependencyCheck whether to perform a dependency check for object * references in the bean instance * @throws BeansException if wiring failed * @see #AUTOWIRE_BY_NAME * @see #AUTOWIRE_BY_TYPE * @see #AUTOWIRE_NO */ void autowireBeanProperties(Object existingBean, int autowireMode, boolean dependencyCheck) throws BeansException; /** * Apply the property values of the bean definition with the given name to * the given bean instance. The bean definition can either define a fully * self-contained bean, reusing its property values, or just property values * meant to be used for existing bean instances. * <p>This method does <i>not</i> autowire bean properties; it just applies * explicitly defined property values. Use the {@link #autowireBeanProperties} * method to autowire an existing bean instance. * <b>Note: This method requires a bean definition for the given name!</b> * <p>Does <i>not</i> apply standard {@link BeanPostProcessor BeanPostProcessors} * callbacks or perform any further initialization of the bean. This interface * offers distinct, fine-grained operations for those purposes, for example * {@link #initializeBean}. However, {@link InstantiationAwareBeanPostProcessor} * callbacks are applied, if applicable to the configuration of the instance. * @param existingBean the existing bean instance * @param beanName the name of the bean definition in the bean factory * (a bean definition of that name has to be available) * @throws org.springframework.beans.factory.NoSuchBeanDefinitionException * if there is no bean definition with the given name * @throws BeansException if applying the property values failed * @see #autowireBeanProperties */ void applyBeanPropertyValues(Object existingBean, String beanName) throws BeansException; /** * Initialize the given raw bean, applying factory callbacks * such as {@code setBeanName} and {@code setBeanFactory}, * also applying all bean post processors (including ones which * might wrap the given raw bean). * <p>Note that no bean definition of the given name has to exist * in the bean factory. The passed-in bean name will simply be used * for callbacks but not checked against the registered bean definitions. * @param existingBean the existing bean instance * @param beanName the name of the bean, to be passed to it if necessary * (only passed to {@link BeanPostProcessor BeanPostProcessors}; * can follow the {@link #ORIGINAL_INSTANCE_SUFFIX} convention in order to * enforce the given instance to be returned, i.e. no proxies etc) * @return the bean instance to use, either the original or a wrapped one * @throws BeansException if the initialization failed * @see #ORIGINAL_INSTANCE_SUFFIX */ Object initializeBean(Object existingBean, String beanName) throws BeansException; /** * Apply {@link BeanPostProcessor BeanPostProcessors} to the given existing bean * instance, invoking their {@code postProcessBeforeInitialization} methods. * The returned bean instance may be a wrapper around the original. * @param existingBean the existing bean instance * @param beanName the name of the bean, to be passed to it if necessary * (only passed to {@link BeanPostProcessor BeanPostProcessors}; * can follow the {@link #ORIGINAL_INSTANCE_SUFFIX} convention in order to * enforce the given instance to be returned, i.e. no proxies etc) * @return the bean instance to use, either the original or a wrapped one * @throws BeansException if any post-processing failed * @see BeanPostProcessor#postProcessBeforeInitialization * @see #ORIGINAL_INSTANCE_SUFFIX */ Object applyBeanPostProcessorsBeforeInitialization(Object existingBean, String beanName) throws BeansException; /** * Apply {@link BeanPostProcessor BeanPostProcessors} to the given existing bean * instance, invoking their {@code postProcessAfterInitialization} methods. * The returned bean instance may be a wrapper around the original. * @param existingBean the existing bean instance * @param beanName the name of the bean, to be passed to it if necessary * (only passed to {@link BeanPostProcessor BeanPostProcessors}; * can follow the {@link #ORIGINAL_INSTANCE_SUFFIX} convention in order to * enforce the given instance to be returned, i.e. no proxies etc) * @return the bean instance to use, either the original or a wrapped one * @throws BeansException if any post-processing failed * @see BeanPostProcessor#postProcessAfterInitialization * @see #ORIGINAL_INSTANCE_SUFFIX */ Object applyBeanPostProcessorsAfterInitialization(Object existingBean, String beanName) throws BeansException; /** * Destroy the given bean instance (typically coming from {@link #createBean}), * applying the {@link org.springframework.beans.factory.DisposableBean} contract as well as * registered {@link DestructionAwareBeanPostProcessor DestructionAwareBeanPostProcessors}. * <p>Any exception that arises during destruction should be caught * and logged instead of propagated to the caller of this method. * @param existingBean the bean instance to destroy */ void destroyBean(Object existingBean); //------------------------------------------------------------------------- // Delegate methods for resolving injection points //------------------------------------------------------------------------- /** * Resolve the bean instance that uniquely matches the given object type, if any, * including its bean name. * <p>This is effectively a variant of {@link #getBean(Class)} which preserves the * bean name of the matching instance. * @param requiredType type the bean must match; can be an interface or superclass * @return the bean name plus bean instance * @throws NoSuchBeanDefinitionException if no matching bean was found * @throws NoUniqueBeanDefinitionException if more than one matching bean was found * @throws BeansException if the bean could not be created * @since 4.3.3 * @see #getBean(Class) */ <T> NamedBeanHolder<T> resolveNamedBean(Class<T> requiredType) throws BeansException; /** * Resolve a bean instance for the given bean name, providing a dependency descriptor * for exposure to target factory methods. * <p>This is effectively a variant of {@link #getBean(String, Class)} which supports * factory methods with an {@link org.springframework.beans.factory.InjectionPoint} * argument. * @param name the name of the bean to look up * @param descriptor the dependency descriptor for the requesting injection point * @return the corresponding bean instance * @throws NoSuchBeanDefinitionException if there is no bean with the specified name * @throws BeansException if the bean could not be created * @since 5.1.5 * @see #getBean(String, Class) */ Object resolveBeanByName(String name, DependencyDescriptor descriptor) throws BeansException; /** * Resolve the specified dependency against the beans defined in this factory. * @param descriptor the descriptor for the dependency (field/method/constructor) * @param requestingBeanName the name of the bean which declares the given dependency * @return the resolved object, or {@code null} if none found * @throws NoSuchBeanDefinitionException if no matching bean was found * @throws NoUniqueBeanDefinitionException if more than one matching bean was found * @throws BeansException if dependency resolution failed for any other reason * @since 2.5 * @see #resolveDependency(DependencyDescriptor, String, Set, TypeConverter) */ @Nullable Object resolveDependency(DependencyDescriptor descriptor, @Nullable String requestingBeanName) throws BeansException; /** * Resolve the specified dependency against the beans defined in this factory. * @param descriptor the descriptor for the dependency (field/method/constructor) * @param requestingBeanName the name of the bean which declares the given dependency * @param autowiredBeanNames a Set that all names of autowired beans (used for * resolving the given dependency) are supposed to be added to * @param typeConverter the TypeConverter to use for populating arrays and collections * @return the resolved object, or {@code null} if none found * @throws NoSuchBeanDefinitionException if no matching bean was found * @throws NoUniqueBeanDefinitionException if more than one matching bean was found * @throws BeansException if dependency resolution failed for any other reason * @since 2.5 * @see DependencyDescriptor */ @Nullable Object resolveDependency(DependencyDescriptor descriptor, @Nullable String requestingBeanName, @Nullable Set<String> autowiredBeanNames, @Nullable TypeConverter typeConverter) throws BeansException; }