ReflectionHelper.java Source code

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Here is the source code for ReflectionHelper.java

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// $Id: ReflectionHelper.java 16271 2009-04-07 20:20:12Z hardy.ferentschik $
/*
* JBoss, Home of Professional Open Source
* Copyright 2008, Red Hat Middleware LLC, and individual contributors
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* 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.beans.Introspector;
import java.lang.annotation.Annotation;
import java.lang.reflect.AccessibleObject;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Member;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.lang.reflect.WildcardType;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

/**
 * Some reflection utility methods.
 *
 * @author Hardy Ferentschik
 */
public class ReflectionHelper {

    @SuppressWarnings("unchecked")
    public static <T> T getAnnotationParameter(Annotation annotation, String parameterName, Class<T> type) {
        try {
            Method m = annotation.getClass().getMethod(parameterName);
            Object o = m.invoke(annotation);
            if (o.getClass().getName().equals(type.getName())) {
                return (T) o;
            } else {
                String msg = "Wrong parameter type. Expected: " + type.getName() + " Actual: "
                        + o.getClass().getName();
                throw new RuntimeException(msg);
            }
        } catch (NoSuchMethodException e) {
            String msg = "The specified annotation defines no parameter '" + parameterName + "'.";
            throw new RuntimeException(msg, e);
        } catch (IllegalAccessException e) {
            String msg = "Unable to get '" + parameterName + "' from " + annotation.getClass().getName();
            throw new RuntimeException(msg, e);
        } catch (InvocationTargetException e) {
            String msg = "Unable to get '" + parameterName + "' from " + annotation.getClass().getName();
            throw new RuntimeException(msg, e);
        }
    }

}