org.hibernate.validator.internal.util.annotationfactory.AnnotationFactory Maven / Gradle / Ivy

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*
* 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,
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* See the License for the specific language governing permissions and
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*/
package org.hibernate.validator.internal.util.annotationfactory;

import java.lang.annotation.Annotation;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Proxy;

import org.hibernate.validator.internal.util.ReflectionHelper;

/**
 * Creates live annotations (actually {@link AnnotationProxy} instances) from {@code AnnotationDescriptor}s.
 *
 * @author Paolo Perrotta
 * @author Davide Marchignoli
 * @author Hardy Ferentschik
 * @see AnnotationProxy
 */
public class AnnotationFactory {

	public static  T create(AnnotationDescriptor descriptor) {
		@SuppressWarnings("unchecked")
		Class proxyClass = (Class) Proxy.getProxyClass(
				ReflectionHelper.getClassLoaderFromClass( descriptor.type() ),
				descriptor.type()
		);
		InvocationHandler handler = new AnnotationProxy( descriptor );
		try {
			return getProxyInstance( proxyClass, handler );
		}
		catch ( RuntimeException e ) {
			throw e;
		}
		catch ( Exception e ) {
			throw new RuntimeException( e );
		}
	}

	private static  T getProxyInstance(Class proxyClass, InvocationHandler handler) throws
			SecurityException, NoSuchMethodException, IllegalArgumentException, InstantiationException,
			IllegalAccessException, InvocationTargetException {
		final Constructor constructor = ReflectionHelper.getConstructor( proxyClass, InvocationHandler.class );
		return ReflectionHelper.newConstructorInstance( constructor, handler );
	}
}