/*
* 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.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;
@Order defines the sort order for an annotated component. The value is optional and represents an order value as defined in the Ordered interface. Lower values have higher priority. The default value is Ordered.LOWEST_PRECEDENCE, indicating 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 @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 @DependsOn declarations (influencing a runtime-determined dependency graph).
Since Spring 4.1, the standard Priority annotation can be used as a drop-in replacement for this annotation in ordering scenarios. Note that @Priority may have additional semantics when a single element has to be picked (see AnnotationAwareOrderComparator.getPriority).
Alternatively, order values may also be determined on a per-instance basis through the Ordered interface, allowing for configuration-determined instance values instead of hard-coded values attached to a particular class.
Consult the javadoc for
OrderComparator for details on the sort semantics for non-ordered objects.
Author: Rod Johnson, Juergen Hoeller See Also: Since: 2.0
/**
* {@code @Order} defines the sort order for an annotated component.
*
* <p>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 lowest priority (losing to any other
* specified order value).
*
* <p><b>NOTE:</b> 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).
*
* <p>Since Spring 4.1, the standard {@link javax.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}).
*
* <p>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.
*
* <p>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 javax.annotation.Priority
*/
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.TYPE, ElementType.METHOD, ElementType.FIELD})
@Documented
public @interface Order {
The order value.
Default is Ordered.LOWEST_PRECEDENCE.
See Also:
/**
* The order value.
* <p>Default is {@link Ordered#LOWEST_PRECEDENCE}.
* @see Ordered#getOrder()
*/
int value() default Ordered.LOWEST_PRECEDENCE;
}