org.springframework.core.annotation.OrderUtils Maven / Gradle / Ivy
/*
* Copyright 2002-2016 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.Annotation;
import org.springframework.util.ClassUtils;
/**
* General utility for determining the order of an object based on its type declaration.
* Handles Spring's {@link Order} annotation as well as {@link javax.annotation.Priority}.
*
* @author Stephane Nicoll
* @author Juergen Hoeller
* @since 4.1
* @see Order
* @see javax.annotation.Priority
*/
@SuppressWarnings("unchecked")
public abstract class OrderUtils {
private static Class priorityAnnotationType = null;
static {
try {
priorityAnnotationType = (Class)
ClassUtils.forName("javax.annotation.Priority", OrderUtils.class.getClassLoader());
}
catch (Throwable ex) {
// javax.annotation.Priority not available, or present but not loadable (on JDK 6)
}
}
/**
* Return the order on the specified {@code type}.
* Takes care of {@link Order @Order} and {@code @javax.annotation.Priority}.
* @param type the type to handle
* @return the order value, or {@code null} if none can be found
* @see #getPriority(Class)
*/
public static Integer getOrder(Class type) {
return getOrder(type, null);
}
/**
* Return the order on the specified {@code type}, or the specified
* default value if none can be found.
*
Takes care of {@link Order @Order} and {@code @javax.annotation.Priority}.
* @param type the type to handle
* @return the priority value, or the specified default order if none can be found
* @see #getPriority(Class)
*/
public static Integer getOrder(Class type, Integer defaultOrder) {
Order order = AnnotationUtils.findAnnotation(type, Order.class);
if (order != null) {
return order.value();
}
Integer priorityOrder = getPriority(type);
if (priorityOrder != null) {
return priorityOrder;
}
return defaultOrder;
}
/**
* Return the value of the {@code javax.annotation.Priority} annotation
* declared on the specified type, or {@code null} if none.
* @param type the type to handle
* @return the priority value if the annotation is declared, or {@code null} if none
*/
public static Integer getPriority(Class type) {
if (priorityAnnotationType != null) {
Annotation priority = AnnotationUtils.findAnnotation(type, priorityAnnotationType);
if (priority != null) {
return (Integer) AnnotationUtils.getValue(priority);
}
}
return null;
}
}