org.jdal.annotation.AnnotatedElementAccessor.java Source code

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Here is the source code for org.jdal.annotation.AnnotatedElementAccessor.java

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/*
 * Copyright 2009-2014 Jose Luis Martin.
 *
 * 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.jdal.annotation;

import java.lang.annotation.Annotation;
import java.lang.reflect.AnnotatedElement;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.PropertyAccessorFactory;
import org.springframework.util.ReflectionUtils;
import org.springframework.util.ReflectionUtils.FieldCallback;
import org.springframework.util.ReflectionUtils.MethodCallback;

/**
 * Utility class for dealing with annotations elements.
 * 
 * @author Jose Luis Martin.
 * @since 2.0
 */
public abstract class AnnotatedElementAccessor {

    private static final Log log = LogFactory.getLog(AnnotatedElementAccessor.class);

    /**
     * Find annotated elements on types
     * @param ann annotation to search
     * @param clazz class to search on.
     * @return List with annotated elements
     */
    public static List<AnnotatedElement> findAnnotatedElements(final Class<? extends Annotation> annotationType,
            Class<?> clazz) {
        final ArrayList<AnnotatedElement> elements = new ArrayList<AnnotatedElement>();
        // Lookup fields
        ReflectionUtils.doWithFields(clazz, new FieldCallback() {

            @Override
            public void doWith(Field field) throws IllegalArgumentException, IllegalAccessException {
                if (field.getAnnotation(annotationType) != null) {
                    elements.add(field);
                }

            }
        });
        // Lookup methods
        ReflectionUtils.doWithMethods(clazz, new MethodCallback() {

            @Override
            public void doWith(Method method) throws IllegalArgumentException, IllegalAccessException {

                if (org.springframework.core.annotation.AnnotationUtils.getAnnotation(method,
                        annotationType) != null)
                    elements.add(method);
            }
        });

        return elements;
    }

    /**
     * Try to set a value on AnnotatedElement.
     * @param element the annotated element.
     * @param value value to set.
     */
    public static void setValue(AnnotatedElement element, Object target, Object value) {
        if (element instanceof Field) {
            Field field = (Field) element;
            ReflectionUtils.makeAccessible(field);
            ReflectionUtils.setField(field, target, value);
        } else if (element instanceof Method) {
            Method method = (Method) element;
            try {
                method.invoke(target, new Object[] { value });
            } catch (Exception e) {
                log.error("Cannot set value on method [" + method.toString() + "]");
            }
        }
    }

    public static Object getValue(AnnotatedElement element, Object target) {
        if (element instanceof Field) {
            ReflectionUtils.makeAccessible((Field) element);
            return ReflectionUtils.getField((Field) element, target);
        } else if (element instanceof Method) {
            Method method = (Method) element;
            String name = method.getName();

            if (name.startsWith("set")) {
                return PropertyAccessorFactory.forBeanPropertyAccess(target)
                        .getPropertyValue(getPropertyName(name));
            }
        }

        return null;
    }

    private static String getPropertyName(String name) {
        return name.charAt(0) + name.substring(1);
    }
}