JAXB2反序列化XML到JavaBean，以及序列化到字符串的功能。

JAXB2MarshallerSample.java

private String coverToXml(FilesInfoBean info) {
    StringWriter writer = new StringWriter();
    try {
        JAXBContext context = JAXBContext.newInstance(info.getClass());
        Marshaller marshaller = context.createMarshaller();
        marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true); //格式化
        marshaller.marshal(info, writer);
    } catch (JAXBException e) {
        e.printStackTrace();
    }
    return writer.toString();
}

UpdateRequestParserImpl.java

 protected UpdateRequestBody parseBody(String body, Class<? extends UpdateRequestBody> requestType) throws  BadUpdateRequestException{
        try {
            JAXBContext context = JAXBContext.newInstance(requestType);
            Unmarshaller unmarshaller = context.createUnmarshaller();
            return (UpdateRequestBody)unmarshaller.unmarshal(new StringReader(body));
        } catch (JAXBException e) {
            logger.error("It occurs error when parsing update request body.Body is:\n\n{}", e, body);
            throw new BadUpdateRequestException.BodyError("It occurs error when parsing update request body.", e);
        }
    }