spring DeferredImportSelector 源码

spring DeferredImportSelector 代码

文件路径：/spring-context/src/main/java/org/springframework/context/annotation/DeferredImportSelector.java

/*
 * Copyright 2002-2020 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.context.annotation;

import org.springframework.core.type.AnnotationMetadata;
import org.springframework.lang.Nullable;

/**
 * A variation of {@link ImportSelector} that runs after all {@code @Configuration} beans
 * have been processed. This type of selector can be particularly useful when the selected
 * imports are {@code @Conditional}.
 *
 * <p>Implementations can also extend the {@link org.springframework.core.Ordered}
 * interface or use the {@link org.springframework.core.annotation.Order} annotation to
 * indicate a precedence against other {@link DeferredImportSelector DeferredImportSelectors}.
 *
 * <p>Implementations may also provide an {@link #getImportGroup() import group} which
 * can provide additional sorting and filtering logic across different selectors.
 *
 * @author Phillip Webb
 * @author Stephane Nicoll
 * @since 4.0
 */
public interface DeferredImportSelector extends ImportSelector {

	/**
	 * Return a specific import group.
	 * <p>The default implementations return {@code null} for no grouping required.
	 * @return the import group class, or {@code null} if none
	 * @since 5.0
	 */
	@Nullable
	default Class<? extends Group> getImportGroup() {
		return null;
	}


	/**
	 * Interface used to group results from different import selectors.
	 * @since 5.0
	 */
	interface Group {

		/**
		 * Process the {@link AnnotationMetadata} of the importing @{@link Configuration}
		 * class using the specified {@link DeferredImportSelector}.
		 */
		void process(AnnotationMetadata metadata, DeferredImportSelector selector);

		/**
		 * Return the {@link Entry entries} of which class(es) should be imported
		 * for this group.
		 */
		Iterable<Entry> selectImports();


		/**
		 * An entry that holds the {@link AnnotationMetadata} of the importing
		 * {@link Configuration} class and the class name to import.
		 */
		class Entry {

			private final AnnotationMetadata metadata;

			private final String importClassName;

			public Entry(AnnotationMetadata metadata, String importClassName) {
				this.metadata = metadata;
				this.importClassName = importClassName;
			}

			/**
			 * Return the {@link AnnotationMetadata} of the importing
			 * {@link Configuration} class.
			 */
			public AnnotationMetadata getMetadata() {
				return this.metadata;
			}

			/**
			 * Return the fully qualified name of the class to import.
			 */
			public String getImportClassName() {
				return this.importClassName;
			}

			@Override
			public boolean equals(@Nullable Object other) {
				if (this == other) {
					return true;
				}
				if (other == null || getClass() != other.getClass()) {
					return false;
				}
				Entry entry = (Entry) other;
				return (this.metadata.equals(entry.metadata) && this.importClassName.equals(entry.importClassName));
			}

			@Override
			public int hashCode() {
				return (this.metadata.hashCode() * 31 + this.importClassName.hashCode());
			}

			@Override
			public String toString() {
				return this.importClassName;
			}
		}
	}

}

相关信息

spring 源码目录

相关文章

spring AdviceMode 源码

spring AdviceModeImportSelector 源码

spring AnnotatedBeanDefinitionReader 源码

spring AnnotationBeanNameGenerator 源码

spring AnnotationConfigApplicationContext 源码

spring AnnotationConfigBeanDefinitionParser 源码

spring AnnotationConfigRegistry 源码

spring AnnotationConfigUtils 源码

spring AnnotationScopeMetadataResolver 源码

spring AspectJAutoProxyRegistrar 源码