@XmlRootElement public class Person { @XmlElement private String name; @XmlElement private int age; } JAXBContext context = JAXBContext.newInstance(Person.class); Marshaller marshaller = context.createMarshaller(); marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true); StringWriter writer = new StringWriter(); marshaller.marshal(person, writer); System.out.println(writer.toString());