org.springframework.core.annotation.Order Maven / Gradle / Ivy
/*
* 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
*
* 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.core.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.Ordered;
/**
* {@code @Order} defines the sort order for an annotated component.
*
* The {@link #value} is optional and represents an order value as defined in the
* {@link Ordered} interface. Lower values have higher priority. The default value is
* {@code Ordered.LOWEST_PRECEDENCE}, indicating the lowest priority (losing to any
* other specified order value).
*
*
NOTE: Since Spring 4.0, annotation-based ordering is supported for many
* kinds of components in Spring, even for collection injection where the order values
* of the target components are taken into account (either from their target class or
* from their {@code @Bean} method). While such order values may influence priorities
* at injection points, please be aware that they do not influence singleton startup
* order which is an orthogonal concern determined by dependency relationships and
* {@code @DependsOn} declarations (influencing a runtime-determined dependency graph).
*
*
Since Spring 4.1, the standard {@link jakarta.annotation.Priority} annotation
* can be used as a drop-in replacement for this annotation in ordering scenarios.
* Note that {@code @Priority} may have additional semantics when a single element
* has to be picked (see {@link AnnotationAwareOrderComparator#getPriority}).
*
*
Alternatively, order values may also be determined on a per-instance basis
* through the {@link Ordered} interface, allowing for configuration-determined
* instance values instead of hard-coded values attached to a particular class.
*
*
Consult the javadoc for {@link org.springframework.core.OrderComparator
* OrderComparator} for details on the sort semantics for non-ordered objects.
*
* @author Rod Johnson
* @author Juergen Hoeller
* @since 2.0
* @see org.springframework.core.Ordered
* @see AnnotationAwareOrderComparator
* @see OrderUtils
* @see jakarta.annotation.Priority
*/
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.TYPE, ElementType.METHOD, ElementType.FIELD})
@Documented
public @interface Order {
/**
* The order value.
*
Default is {@link Ordered#LOWEST_PRECEDENCE}.
* @see Ordered#getOrder()
*/
int value() default Ordered.LOWEST_PRECEDENCE;
}