JaxbElementProvider.java

/**
 * Copyright 2005-2014 Restlet
 * 
 * The contents of this file are subject to the terms of one of the following
 * open source licenses: Apache 2.0 or or EPL 1.0 (the "Licenses"). You can
 * select the license that you prefer but you may not use this file except in
 * compliance with one of these Licenses.
 * 
 * You can obtain a copy of the Apache 2.0 license at
 * http://www.opensource.org/licenses/apache-2.0
 * 
 * You can obtain a copy of the EPL 1.0 license at
 * http://www.opensource.org/licenses/eclipse-1.0
 * 
 * See the Licenses for the specific language governing permissions and
 * limitations under the Licenses.
 * 
 * Alternatively, you can obtain a royalty free commercial license with less
 * limitations, transferable or non-transferable, directly at
 * http://restlet.com/products/restlet-framework
 * 
 * Restlet is a registered trademark of Restlet S.A.S.
 */

package org.restlet.ext.jaxrs.internal.provider;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.annotation.Annotation;
import java.lang.reflect.Type;
import java.util.logging.Logger;

import javax.ws.rs.Consumes;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.ext.MessageBodyReader;
import javax.ws.rs.ext.MessageBodyWriter;
import javax.ws.rs.ext.Provider;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBElement;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Unmarshaller;
import javax.xml.transform.stream.StreamSource;

import org.restlet.Context;
import org.restlet.ext.jaxrs.internal.exceptions.ImplementationException;
import org.restlet.ext.jaxrs.internal.util.Util;

/**
 * Provider for {@link JAXBElement}s.
 * 
 * @author Stephan Koops
 * @see MessageBodyReader
 * @see MessageBodyWriter
 */
@Provider
@Produces({ "application/xml", MediaType.TEXT_XML, "application/*+xml" })
@Consumes({ "application/xml", MediaType.TEXT_XML, "application/*+xml" })
public class JaxbElementProvider extends AbstractJaxbProvider<JAXBElement<?>> {

    private final Logger logger = Context.getCurrentLogger();

    @Override
    Logger getLogger() {
        return this.logger;
    }

    /**
     * @see MessageBodyReader#isReadable(Class, Type, Annotation[])
     */
    @Override
    public boolean isReadable(Class<?> type, Type genericType,
            Annotation[] annotations, MediaType mediaType) {
        if (!JAXBElement.class.isAssignableFrom(type)) {
            return false;
        }
        return Util.getGenericClass(genericType) != null;
    }

    /**
     * @see MessageBodyWriter#isWriteable(Class, Type, Annotation[])
     */
    @Override
    public boolean isWriteable(Class<?> type, Type genericType,
            Annotation[] annotations, MediaType mediaType) {
        if (!type.isAssignableFrom(JAXBElement.class)) {
            return false;
        }
        return Util.getGenericClass(genericType) != null;
    }

    /**
     * @see MessageBodyReader#readFrom(Class, Type, MediaType, Annotation[],
     *      MultivaluedMap, InputStream)
     */
    @Override
    public JAXBElement<?> readFrom(Class<JAXBElement<?>> type,
            Type genericType, Annotation[] annotations, MediaType mediaType,
            MultivaluedMap<String, String> httpResponseHeaders,
            InputStream entityStream) throws IOException {
        final Class<?> clazz = Util.getGenericClass(genericType);
        if (clazz == null) {
            throw new ImplementationException(
                    "The JaxbElement provider has gotten a type it could not unmarshal. Perhaps is the JaxbElementProvider not consistent to itself.");
        }
        try {
            final JAXBContext jaxbContext = getJaxbContext(clazz);
            final Unmarshaller unmarshaller = jaxbContext.createUnmarshaller();
            JAXBElement<?> je = unmarshaller.unmarshal(new StreamSource(
                    entityStream), type);
            return je;
        } catch (JAXBException e) {
            final String message = "Could not unmarshal to " + type.getName();
            throw logAndIOExc(getLogger(), message, e);
        }
    }

    /**
     * @see MessageBodyWriter#writeTo(Object, Class, Type, Annotation[],
     *      MediaType, MultivaluedMap, OutputStream)
     */
    @Override
    public void writeTo(JAXBElement<?> jaxbElement, Class<?> type,
            Type genericType, Annotation[] annotations, MediaType mediaType,
            MultivaluedMap<String, Object> httpResponseHeaders,
            OutputStream entityStream) throws IOException {
        marshal(jaxbElement.getValue(), entityStream);
    }
}