AnnotationClassExternalizerFactory.java

/*
 * JBoss, Home of Professional Open Source.
 * Copyright 2014 Red Hat, Inc., and individual contributors
 * as indicated by the @author tags.
 *
 * 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.jboss.marshalling;

/**
 * An externalizer factory which looks for the presence of the {@link org.jboss.marshalling.Externalize Externalize} annotation.
 */
public class AnnotationClassExternalizerFactory implements ClassExternalizerFactory {

    /**
     * Construct a new instance.
     */
    public AnnotationClassExternalizerFactory() {
    }

    /** {@inheritDoc} */
    public Externalizer getExternalizer(final Class<?> type) {
        final Externalize ann = type.getAnnotation(Externalize.class);
        if (ann == null) {
            return null;
        } else {
            try {
                return ann.value().newInstance();
            } catch (Exception e) {
                throw new IllegalArgumentException("Cannot instantiate externalizer for " + type, e);
            }
        }
    }
}