org.springframework.beans.factory.annotation.Autowired Maven / Gradle / Ivy
/*
* Copyright 2002-2008 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.beans.factory.annotation;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
* Marks a constructor, field, setter method or config method as to be
* autowired by Spring's dependency injection facilities.
*
* Only one constructor (at max) of any given bean class may carry this
* annotation, indicating the constructor to autowire when used as a Spring
* bean. Such a constructor does not have to be public.
*
*
Fields are injected right after construction of a bean, before any
* config methods are invoked. Such a config field does not have to be public.
*
*
Config methods may have an arbitrary name and any number of arguments;
* each of those arguments will be autowired with a matching bean in the
* Spring container. Bean property setter methods are effectively just
* a special case of such a general config method. Such config methods
* do not have to be public.
*
*
In the case of multiple argument methods, the 'required' parameter is
* applicable for all arguments.
*
*
In case of a {@link java.util.Collection} or {@link java.util.Map}
* dependency type, the container will autowire all beans matching the
* declared value type. In case of a Map, the keys must be declared as
* type String and will be resolved to the corresponding bean names.
*
*
Please do consult the javadoc for the {@link AutowiredAnnotationBeanPostProcessor}
* class (which, by default, checks for the presence of this annotation).
*
* @author Juergen Hoeller
* @author Mark Fisher
* @since 2.5
* @see AutowiredAnnotationBeanPostProcessor
*/
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.CONSTRUCTOR, ElementType.FIELD, ElementType.METHOD})
public @interface Autowired {
/**
* Declares whether the annotated dependency is required.
*
Defaults to true.
*/
boolean required() default true;
}