experimental/trunk_client_side_validation/core/src/main/java/org/apache/myfaces/extensions/validator/core/annotation/extractor/DefaultAnnotationExtractorFactory.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.myfaces.extensions.validator.core.annotation.extractor;

import org.apache.myfaces.extensions.validator.core.WebXmlParameter;
import org.apache.myfaces.extensions.validator.util.ClassUtils;
import org.apache.myfaces.extensions.validator.util.ExtValUtils;

import java.util.ArrayList;
import java.util.List;

/**
 * @author Gerhard Petracek
 */
public class DefaultAnnotationExtractorFactory implements
    AnnotationExtractorFactory
{

    private static AnnotationExtractor annotationExtractor = null;

    public AnnotationExtractor create()
    {
        if (annotationExtractor == null)
        {
            List<String> annotationExtractorClassNames = new ArrayList<String>();

            annotationExtractorClassNames
                .add(WebXmlParameter.CUSTOM_ANNOTATION_EXTRACTOR);
            annotationExtractorClassNames.add(ExtValUtils
                .getInformationProviderBean()
                .getCustomAnnotationExtractor());
            annotationExtractorClassNames
                .add(DefaultComponentAnnotationExtractor.class.getName());

            for (String className : annotationExtractorClassNames)
            {
                annotationExtractor = (AnnotationExtractor) ClassUtils
                    .tryToInstantiateClassForName(className);

                if (annotationExtractor != null)
                {
                    //TODO logging
                    break;
                }
            }
        }

        return annotationExtractor;
    }
}