Java Reflection Annotation getAnnotationFromWeldBean(Object target, Class annotation)

License

Parameter

Return

Declaration

public static <A extends Annotation> A getAnnotationFromWeldBean(Object target, Class<A> annotation) 

Method Source Code

//package com.java2s;
//License from project: LGPL 

import java.lang.annotation.Annotation;
import java.lang.invoke.MethodHandles;

import java.lang.reflect.Method;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class Main {
    private static final Logger LOGGER = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
    private static final String ERROR_OCCURED_WITH_REFLECTION_ACCESS = "Error occured with reflection access";

    /**/* w ww .j a va2 s .c  om*/
     * Gets the annotation from weld bean. <br>
     * The methods tries to retrieve the annotation from the class of the given object first. If not found tries to
     * fetch the getTargetClass method that is method from a Weld proxy class (@link
     * org.jboss.interceptor.util.proxy.TargetInstanceProxy#getTargetClass()). If such method is found the annotation is
     * locked on the object returned from the method call.
     *
     * @param <A>
     *            the annotation type
     * @param target
     *            the target object to fetch the annotation from
     * @param annotation
     *            the annotation class
     * @return the found annotation or <code>null</code> if the annotation is not present on the given class or the
     *         given object is not a weld proxy or not present on the proxy
     */
    public static <A extends Annotation> A getAnnotationFromWeldBean(Object target, Class<A> annotation) {
        A extension = target.getClass().getAnnotation(annotation);
        if (extension == null) {
            Method declaredMethod = null;
            try {
                declaredMethod = target.getClass().getDeclaredMethod("getTargetClass", (Class<?>[]) null);
                declaredMethod.setAccessible(true);
                Object invoke = declaredMethod.invoke(target, (Object[]) null);
                if (invoke instanceof Class) {
                    Class<?> targetClass = (Class<?>) invoke;
                    extension = targetClass.getAnnotation(annotation);
                }
            } catch (Exception e) {
                // probably not a weld proxy class
                LOGGER.warn(ERROR_OCCURED_WITH_REFLECTION_ACCESS, e);
            }
        }
        return extension;
    }
}

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