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/* * Copyright 2002-2012 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.parsing; import org.springframework.beans.BeanMetadataElement; import org.springframework.beans.factory.config.BeanDefinition; import org.springframework.beans.factory.config.BeanReference; /** * Interface that describes the logical view of a set of {@link BeanDefinition BeanDefinitions} * and {@link BeanReference BeanReferences} as presented in some configuration context. * * <p>With the introduction of {@link org.springframework.beans.factory.xml.NamespaceHandler pluggable custom XML tags}, * it is now possible for a single logical configuration entity, in this case an XML tag, to * create multiple {@link BeanDefinition BeanDefinitions} and {@link BeanReference RuntimeBeanReferences} * in order to provide more succinct configuration and greater convenience to end users. As such, it can * no longer be assumed that each configuration entity (e.g. XML tag) maps to one {@link BeanDefinition}. * For tool vendors and other users who wish to present visualization or support for configuring Spring * applications it is important that there is some mechanism in place to tie the {@link BeanDefinition BeanDefinitions} * in the {@link org.springframework.beans.factory.BeanFactory} back to the configuration data in a way * that has concrete meaning to the end user. As such, {@link org.springframework.beans.factory.xml.NamespaceHandler} * implementations are able to publish events in the form of a {@code ComponentDefinition} for each * logical entity being configured. Third parties can then {@link ReaderEventListener subscribe to these events}, * allowing for a user-centric view of the bean metadata. * * <p>Each {@code ComponentDefinition} has a {@link #getSource source object} which is configuration-specific. * In the case of XML-based configuration this is typically the {@link org.w3c.dom.Node} which contains the user * supplied configuration information. In addition to this, each {@link BeanDefinition} enclosed in a * {@code ComponentDefinition} has its own {@link BeanDefinition#getSource() source object} which may point * to a different, more specific, set of configuration data. Beyond this, individual pieces of bean metadata such * as the {@link org.springframework.beans.PropertyValue PropertyValues} may also have a source object giving an * even greater level of detail. Source object extraction is handled through the * {@link SourceExtractor} which can be customized as required. * * <p>Whilst direct access to important {@link BeanReference BeanReferences} is provided through * {@link #getBeanReferences}, tools may wish to inspect all {@link BeanDefinition BeanDefinitions} to gather * the full set of {@link BeanReference BeanReferences}. Implementations are required to provide * all {@link BeanReference BeanReferences} that are required to validate the configuration of the * overall logical entity as well as those required to provide full user visualisation of the configuration. * It is expected that certain {@link BeanReference BeanReferences} will not be important to * validation or to the user view of the configuration and as such these may be omitted. A tool may wish to * display any additional {@link BeanReference BeanReferences} sourced through the supplied * {@link BeanDefinition BeanDefinitions} but this is not considered to be a typical case. * * <p>Tools can determine the important of contained {@link BeanDefinition BeanDefinitions} by checking the * {@link BeanDefinition#getRole role identifier}. The role is essentially a hint to the tool as to how * important the configuration provider believes a {@link BeanDefinition} is to the end user. It is expected * that tools will <strong>not</strong> display all {@link BeanDefinition BeanDefinitions} for a given * {@code ComponentDefinition} choosing instead to filter based on the role. Tools may choose to make * this filtering user configurable. Particular notice should be given to the * {@link BeanDefinition#ROLE_INFRASTRUCTURE INFRASTRUCTURE role identifier}. {@link BeanDefinition BeanDefinitions} * classified with this role are completely unimportant to the end user and are required only for * internal implementation reasons. * * @author Rob Harrop * @author Juergen Hoeller * @since 2.0 * @see AbstractComponentDefinition * @see CompositeComponentDefinition * @see BeanComponentDefinition * @see ReaderEventListener#componentRegistered(ComponentDefinition) */ public interface ComponentDefinition extends BeanMetadataElement { /** * Get the user-visible name of this {@code ComponentDefinition}. * <p>This should link back directly to the corresponding configuration data * for this component in a given context. */ String getName(); /** * Return a friendly description of the described component. * <p>Implementations are encouraged to return the same value from * {@code toString()}. */ String getDescription(); /** * Return the {@link BeanDefinition BeanDefinitions} that were registered * to form this {@code ComponentDefinition}. * <p>It should be noted that a {@code ComponentDefinition} may well be related with * other {@link BeanDefinition BeanDefinitions} via {@link BeanReference references}, * however these are <strong>not</strong> included as they may be not available immediately. * Important {@link BeanReference BeanReferences} are available from {@link #getBeanReferences()}. * @return the array of BeanDefinitions, or an empty array if none */ BeanDefinition[] getBeanDefinitions(); /** * Return the {@link BeanDefinition BeanDefinitions} that represent all relevant * inner beans within this component. * <p>Other inner beans may exist within the associated {@link BeanDefinition BeanDefinitions}, * however these are not considered to be needed for validation or for user visualization. * @return the array of BeanDefinitions, or an empty array if none */ BeanDefinition[] getInnerBeanDefinitions(); /** * Return the set of {@link BeanReference BeanReferences} that are considered * to be important to this {@code ComponentDefinition}. * <p>Other {@link BeanReference BeanReferences} may exist within the associated * {@link BeanDefinition BeanDefinitions}, however these are not considered * to be needed for validation or for user visualization. * @return the array of BeanReferences, or an empty array if none */ BeanReference[] getBeanReferences(); }