/*
* Copyright 2002-2017 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
*
* http://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;
import org.springframework.core.env.AbstractEnvironment;
import org.springframework.core.env.ConfigurableEnvironment;
/**
* Indicates that a component is eligible for registration when one or more
* {@linkplain #value specified profiles} are active.
*
* <p>A <em>profile</em> is a named logical grouping that may be activated
* programmatically via {@link ConfigurableEnvironment#setActiveProfiles} or declaratively
* by setting the {@link AbstractEnvironment#ACTIVE_PROFILES_PROPERTY_NAME
* spring.profiles.active} property as a JVM system property, as an
* environment variable, or as a Servlet context parameter in {@code web.xml}
* for web applications. Profiles may also be activated declaratively in
* integration tests via the {@code @ActiveProfiles} annotation.
*
* <p>The {@code @Profile} annotation may be used in any of the following ways:
* <ul>
* <li>as a type-level annotation on any class directly or indirectly annotated with
* {@code @Component}, including {@link Configuration @Configuration} classes</li>
* <li>as a meta-annotation, for the purpose of composing custom stereotype annotations</li>
* <li>as a method-level annotation on any {@link Bean @Bean} method</li>
* </ul>
*
* <p>If a {@code @Configuration} class is marked with {@code @Profile}, all of the
* {@code @Bean} methods and {@link Import @Import} annotations associated with that class
* will be bypassed unless one or more of the specified profiles are active. This is
* analogous to the behavior in Spring XML: if the {@code profile} attribute of the
* {@code beans} element is supplied e.g., {@code <beans profile="p1,p2">}, the
* {@code beans} element will not be parsed unless at least profile 'p1' or 'p2' has been
* activated. Likewise, if a {@code @Component} or {@code @Configuration} class is marked
* with {@code @Profile({"p1", "p2"})}, that class will not be registered or processed unless
* at least profile 'p1' or 'p2' has been activated.
*
* <p>If a given profile is prefixed with the NOT operator ({@code !}), the annotated
* component will be registered if the profile is <em>not</em> active — for example,
* given {@code @Profile({"p1", "!p2"})}, registration will occur if profile 'p1' is active
* or if profile 'p2' is <em>not</em> active.
*
* <p>If the {@code @Profile} annotation is omitted, registration will occur regardless
* of which (if any) profiles are active.
*
* <p><b>NOTE:</b> With {@code @Profile} on {@code @Bean} methods, a special scenario may
* apply: In the case of overloaded {@code @Bean} methods of the same Java method name
* (analogous to constructor overloading), an {@code @Profile} condition needs to be
* consistently declared on all overloaded methods. If the conditions are inconsistent,
* only the condition on the first declaration among the overloaded methods will matter.
* {@code @Profile} can therefore not be used to select an overloaded method with a
* particular argument signature over another; resolution between all factory methods
* for the same bean follows Spring's constructor resolution algorithm at creation time.
* <b>Use distinct Java method names pointing to the same {@link @Bean#name bean name}
* if you'd like to define alternative beans with different profile conditions</b>;
* see {@code ProfileDatabaseConfig} in {@link Configuration @Configuration}'s javadoc.
*
* <p>When defining Spring beans via XML, the {@code "profile"} attribute of the
* {@code <beans>} element may be used. See the documentation in the
* {@code spring-beans} XSD (version 3.1 or greater) for details.
*
* @author Chris Beams
* @author Phillip Webb
* @author Sam Brannen
* @since 3.1
* @see ConfigurableEnvironment#setActiveProfiles
* @see ConfigurableEnvironment#setDefaultProfiles
* @see AbstractEnvironment#ACTIVE_PROFILES_PROPERTY_NAME
* @see AbstractEnvironment#DEFAULT_PROFILES_PROPERTY_NAME
* @see Conditional
* @see org.springframework.test.context.ActiveProfiles
*/
@Target({ElementType.TYPE, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Conditional(ProfileCondition.class)
public @interface Profile {
/**
* The set of profiles for which the annotated component should be registered.
*/
String[] value();
}