Java Reflection Annotation getAnnotation(Class type, Class annotationType)

License

Declaration

public static <A extends Annotation> A getAnnotation(Class<?> type, Class<A> annotationType) 

Method Source Code

//package com.java2s;
/*/*from ww w  .  ja v  a  2 s  .  c  om*/
 * Copyright 2019 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;
import java.lang.annotation.Inherited;

public class Main {
    public static <A extends Annotation> A getAnnotation(Class<?> type, Class<A> annotationType) {
        return getAnnotation(type, annotationType, true);
    }

    private static <A extends Annotation> A getAnnotation(Class<?> type, Class<A> annotationType,
            boolean checkType) {
        A annotation;
        if (checkType) {
            annotation = type.getAnnotation(annotationType);
            if (annotation != null) {
                return annotation;
            }
        }

        if (annotationType.getAnnotation(Inherited.class) != null) {
            for (Class<?> anInterface : type.getInterfaces()) {
                annotation = getAnnotation(anInterface, annotationType, true);
                if (annotation != null) {
                    return annotation;
                }
            }
        }

        if (type.isInterface() || type.equals(Object.class)) {
            return null;
        } else {
            return getAnnotation(type.getSuperclass(), annotationType, false);
        }
    }
}

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