https://github.com/spring-projects/spring-framework: Spring Context (Spring IO)
  • Juergen Hoeller 
/*
 * Copyright 2002-2018 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;


Beans on which the current bean depends. Any beans specified are guaranteed to be
created by the container before this bean. Used infrequently in cases where a bean
does not explicitly depend on another through properties or constructor arguments,
but rather depends on the side effects of another bean's initialization.

A depends-on declaration can specify both an initialization-time dependency and,
in the case of singleton beans only, a corresponding destruction-time dependency.
Dependent beans that define a depends-on relationship with a given bean are destroyed
first, prior to the given bean itself being destroyed. Thus, a depends-on declaration
can also control shutdown order.

May be used on any class directly or indirectly annotated with Component or on methods annotated with Bean. 
Using DependsOn at the class level has no effect unless component-scanning is being used. If a DependsOn-annotated class is declared via XML, DependsOn annotation metadata is ignored, and <bean depends-on="..."/> is respected instead. 
Author:Juergen Hoeller
Since:3.0
/**
 * Beans on which the current bean depends. Any beans specified are guaranteed to be
 * created by the container before this bean. Used infrequently in cases where a bean
 * does not explicitly depend on another through properties or constructor arguments,
 * but rather depends on the side effects of another bean's initialization.
 *
 * <p>A depends-on declaration can specify both an initialization-time dependency and,
 * in the case of singleton beans only, a corresponding destruction-time dependency.
 * Dependent beans that define a depends-on relationship with a given bean are destroyed
 * first, prior to the given bean itself being destroyed. Thus, a depends-on declaration
 * can also control shutdown order.
 *
 * <p>May be used on any class directly or indirectly annotated with
 * {@link org.springframework.stereotype.Component} or on methods annotated
 * with {@link Bean}.
 *
 * <p>Using {@link DependsOn} at the class level has no effect unless component-scanning
 * is being used. If a {@link DependsOn}-annotated class is declared via XML,
 * {@link DependsOn} annotation metadata is ignored, and
 * {@code <bean depends-on="..."/>} is respected instead.
 *
 * @author Juergen Hoeller
 * @since 3.0
 */
@Target({ElementType.TYPE, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface DependsOn {

	String[] value() default {};

}