protected String marshallerEx(Tickets tickets) throws JAXBException {

    JAXBContext jaxbContext = JAXBContext.newInstance(Tickets.class);
    Marshaller jaxbMarshaller = jaxbContext.createMarshaller();

    jaxbMarshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
    StringWriter sw = new StringWriter();

    // Marshal the tickets list in console
    jaxbMarshaller.marshal(tickets, sw);

    LOGGER.info("marshal -> " + sw.toString());

    return sw.toString();
}

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<tickets>
    <ticket>
        <assignedQueueId>61</assignedQueueId>
        <category>11</category>
        <cause>0</cause>
        <createDate>2015-08-19T13:34:18-04:00</createDate>
        <customFields/>
    </ticket>
</tickets>

"<?xml version="1.0" encoding="UTF-8" standalone="yes"?>n<tickets>n    <ticket>n        <assignedQueueId>61</assignedQueueId>n        <category>11</category>n        <cause>0</cause>n        <createDate>2015-08-19T13:34:18-04:00</createDate>n        <customFields/>n    </ticket>n</tickets>n"

HttpHeaders responseHeaders = new HttpHeaders();
responseHeaders.set("content-type", "text/plain");
return new ResponseEntity<String>(marshallerEx(tickets), responseHeaders, HttpStatus.OK);