jails.http.converter.xml.Jaxb2RootElementHttpMessageConverter.java Source code

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Here is the source code for jails.http.converter.xml.Jaxb2RootElementHttpMessageConverter.java

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/*
 * Copyright 2002-2010 the original author or authors.
 *
 * 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 jails.http.converter.xml;

import jails.http.HttpHeaders;
import jails.http.MediaType;
import jails.http.converter.HttpMessageConversionException;
import jails.http.converter.HttpMessageNotReadableException;
import jails.http.converter.HttpMessageNotWritableException;

import java.io.IOException;
import javax.xml.bind.JAXBElement;
import javax.xml.bind.JAXBException;
import javax.xml.bind.MarshalException;
import javax.xml.bind.Marshaller;
import javax.xml.bind.PropertyException;
import javax.xml.bind.UnmarshalException;
import javax.xml.bind.Unmarshaller;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlType;
import javax.xml.transform.Result;
import javax.xml.transform.Source;

import org.springframework.core.annotation.AnnotationUtils;
import org.springframework.util.ClassUtils;

/**
 * Implementation of {@link jails.http.converter.HttpMessageConverter HttpMessageConverter} that can read
 * and write XML using JAXB2.
 *
 * <p>This converter can read classes annotated with {@link XmlRootElement} and {@link XmlType}, and write classes
 * annotated with with {@link XmlRootElement}, or subclasses thereof.
 *
 * @author Arjen Poutsma
 * @since 3.0
 */
public class Jaxb2RootElementHttpMessageConverter extends AbstractJaxb2HttpMessageConverter<Object> {

    @Override
    public boolean canRead(Class<?> clazz, MediaType mediaType) {
        return (clazz.isAnnotationPresent(XmlRootElement.class) || clazz.isAnnotationPresent(XmlType.class))
                && canRead(mediaType);
    }

    @Override
    public boolean canWrite(Class<?> clazz, MediaType mediaType) {
        return AnnotationUtils.findAnnotation(clazz, XmlRootElement.class) != null && canWrite(mediaType);
    }

    @Override
    protected boolean supports(Class<?> clazz) {
        // should not be called, since we override canRead/Write
        throw new UnsupportedOperationException();
    }

    @Override
    protected Object readFromSource(Class<?> clazz, HttpHeaders headers, Source source) throws IOException {
        try {
            Unmarshaller unmarshaller = createUnmarshaller(clazz);
            if (clazz.isAnnotationPresent(XmlRootElement.class)) {
                return unmarshaller.unmarshal(source);
            } else {
                JAXBElement jaxbElement = unmarshaller.unmarshal(source, clazz);
                return jaxbElement.getValue();
            }
        } catch (UnmarshalException ex) {
            throw new HttpMessageNotReadableException("Could not unmarshal to [" + clazz + "]: " + ex.getMessage(),
                    ex);

        } catch (JAXBException ex) {
            throw new HttpMessageConversionException("Could not instantiate JAXBContext: " + ex.getMessage(), ex);
        }
    }

    @Override
    protected void writeToResult(Object o, HttpHeaders headers, Result result) throws IOException {
        try {
            Class clazz = ClassUtils.getUserClass(o);
            Marshaller marshaller = createMarshaller(clazz);
            setCharset(headers.getContentType(), marshaller);
            marshaller.marshal(o, result);
        } catch (MarshalException ex) {
            throw new HttpMessageNotWritableException("Could not marshal [" + o + "]: " + ex.getMessage(), ex);
        } catch (JAXBException ex) {
            throw new HttpMessageConversionException("Could not instantiate JAXBContext: " + ex.getMessage(), ex);
        }
    }

    private void setCharset(MediaType contentType, Marshaller marshaller) throws PropertyException {
        if (contentType != null && contentType.getCharSet() != null) {
            marshaller.setProperty(Marshaller.JAXB_ENCODING, contentType.getCharSet().name());
        }
    }

}