Java tutorial
/* * Copyright 2012-2019 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.boot.autoconfigure; import java.lang.annotation.Documented; import java.lang.annotation.ElementType; import java.lang.annotation.Inherited; import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; import java.lang.annotation.Target; import org.springframework.boot.autoconfigure.condition.ConditionalOnBean; import org.springframework.boot.autoconfigure.condition.ConditionalOnClass; import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean; import org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory; import org.springframework.boot.web.servlet.server.ServletWebServerFactory; import org.springframework.context.annotation.Conditional; import org.springframework.context.annotation.Configuration; import org.springframework.context.annotation.Import; import org.springframework.core.io.support.SpringFactoriesLoader; /** * Enable auto-configuration of the Spring Application Context, attempting to guess and * configure beans that you are likely to need. Auto-configuration classes are usually * applied based on your classpath and what beans you have defined. For example, if you * have {@code tomcat-embedded.jar} on your classpath you are likely to want a * {@link TomcatServletWebServerFactory} (unless you have defined your own * {@link ServletWebServerFactory} bean). * <p> * When using {@link SpringBootApplication @SpringBootApplication}, the auto-configuration * of the context is automatically enabled and adding this annotation has therefore no * additional effect. * <p> * Auto-configuration tries to be as intelligent as possible and will back-away as you * define more of your own configuration. You can always manually {@link #exclude()} any * configuration that you never want to apply (use {@link #excludeName()} if you don't * have access to them). You can also exclude them via the * {@code spring.autoconfigure.exclude} property. Auto-configuration is always applied * after user-defined beans have been registered. * <p> * The package of the class that is annotated with {@code @EnableAutoConfiguration}, * usually via {@code @SpringBootApplication}, has specific significance and is often used * as a 'default'. For example, it will be used when scanning for {@code @Entity} classes. * It is generally recommended that you place {@code @EnableAutoConfiguration} (if you're * not using {@code @SpringBootApplication}) in a root package so that all sub-packages * and classes can be searched. * <p> * Auto-configuration classes are regular Spring {@link Configuration @Configuration} * beans. They are located using the {@link SpringFactoriesLoader} mechanism (keyed * against this class). Generally auto-configuration beans are * {@link Conditional @Conditional} beans (most often using * {@link ConditionalOnClass @ConditionalOnClass} and * {@link ConditionalOnMissingBean @ConditionalOnMissingBean} annotations). * * @author Phillip Webb * @author Stephane Nicoll * @since 1.0.0 * @see ConditionalOnBean * @see ConditionalOnMissingBean * @see ConditionalOnClass * @see AutoConfigureAfter * @see SpringBootApplication */ @Target(ElementType.TYPE) @Retention(RetentionPolicy.RUNTIME) @Documented @Inherited @AutoConfigurationPackage @Import(AutoConfigurationImportSelector.class) public @interface EnableAutoConfiguration { String ENABLED_OVERRIDE_PROPERTY = "spring.boot.enableautoconfiguration"; /** * Exclude specific auto-configuration classes such that they will never be applied. * @return the classes to exclude */ Class<?>[] exclude() default {}; /** * Exclude specific auto-configuration class names such that they will never be * applied. * @return the class names to exclude * @since 1.3.0 */ String[] excludeName() default {}; }