org.springframework.context.annotation.Conditional Maven / Gradle / Ivy
/*
* 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 java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
* Indicates that a component is only eligible for registration when all
* {@linkplain #value specified conditions} match.
*
* A condition is any state that can be determined programmatically
* before the bean definition is due to be registered (see {@link Condition} for details).
*
*
The {@code @Conditional} annotation may be used in any of the following ways:
*
* - as a type-level annotation on any class directly or indirectly annotated with
* {@code @Component}, including {@link Configuration @Configuration} classes
* - as a meta-annotation, for the purpose of composing custom stereotype
* annotations
* - as a method-level annotation on any {@link Bean @Bean} method
*
*
* If a {@code @Configuration} class is marked with {@code @Conditional},
* all of the {@code @Bean} methods, {@link Import @Import} annotations, and
* {@link ComponentScan @ComponentScan} annotations associated with that
* class will be subject to the conditions.
*
*
NOTE: Inheritance of {@code @Conditional} annotations
* is not supported; any conditions from superclasses or from overridden
* methods will not be considered. In order to enforce these semantics,
* {@code @Conditional} itself is not declared as
* {@link java.lang.annotation.Inherited @Inherited}; furthermore, any
* custom composed annotation that is meta-annotated with
* {@code @Conditional} must not be declared as {@code @Inherited}.
*
* @author Phillip Webb
* @author Sam Brannen
* @since 4.0
* @see Condition
*/
@Target({ElementType.TYPE, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface Conditional {
/**
* All {@link Condition} classes that must {@linkplain Condition#matches match}
* in order for the component to be registered.
*/
Class[] value();
}