Java Reflection Annotation Find findAnnotationDeclaringClass(Class<? extends Annotation> annotationType, Class<?> clazz)

Description

Find the first Class in the inheritance hierarchy of the specified clazz (including the specified clazz itself) which declares an annotation for the specified annotationType , or null if not found.

License

Apache License

Parameter

Parameter	Description
annotationType	the annotation type to look for, both locally and as a meta-annotation
clazz	the class on which to check for the annotation (may be null )

Return

the first in the inheritance hierarchy of the specified clazz which declares an annotation for the specified annotationType , or null if not found

Declaration

public static Class<?> findAnnotationDeclaringClass(Class<? extends Annotation> annotationType,
        Class<?> clazz)

Method Source Code


//package com.java2s;
/*/*from w ww . j a  va2  s. c  om*/
 * Copyright 2002-2014 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.
 */

import java.lang.annotation.Annotation;

public class Main {
    /**
     * Find the first {@link Class} in the inheritance hierarchy of the specified {@code clazz}
     * (including the specified {@code clazz} itself) which declares an annotation for the
     * specified {@code annotationType}, or {@code null} if not found. If the supplied
     * {@code clazz} is {@code null}, {@code null} will be returned.
     * <p>If the supplied {@code clazz} is an interface, only the interface itself will be checked;
     * the inheritance hierarchy for interfaces will not be traversed.
     * <p>The standard {@link Class} API does not provide a mechanism for determining which class
     * in an inheritance hierarchy actually declares an {@link Annotation}, so we need to handle
     * this explicitly.
     * @param annotationType the annotation type to look for, both locally and as a meta-annotation
     * @param clazz the class on which to check for the annotation (may be {@code null})
     * @return the first {@link Class} in the inheritance hierarchy of the specified {@code clazz}
     * which declares an annotation for the specified {@code annotationType}, or {@code null}
     * if not found
     * @see Class#isAnnotationPresent(Class)
     * @see Class#getDeclaredAnnotations()
     * @see #findAnnotationDeclaringClassForTypes(List, Class)
     * @see #isAnnotationDeclaredLocally(Class, Class)
     */
    public static Class<?> findAnnotationDeclaringClass(Class<? extends Annotation> annotationType,
            Class<?> clazz) {
        if (clazz == null || clazz.equals(Object.class)) {
            return null;
        }
        if (isAnnotationDeclaredLocally(annotationType, clazz)) {
            return clazz;
        }
        return findAnnotationDeclaringClass(annotationType, clazz.getSuperclass());
    }

    public static boolean isAnnotationDeclaredLocally(Class<? extends Annotation> annotationType, Class<?> clazz) {
        boolean declaredLocally = false;
        for (Annotation annotation : clazz.getDeclaredAnnotations()) {
            if (annotation.annotationType().equals(annotationType)) {
                declaredLocally = true;
                break;
            }
        }
        return declaredLocally;
    }
}

Java Reflection Annotation Find findAnnotationDeclaringClass(Class annotationType, Class clazz)