如何获取XmlType的String表示？

Question

是否可以将javax.xml.bind.annotation.XmlType转换为XML的String表示形式？

例:

以下类Req来自第三方库,因此我无法覆盖toString()方法.

@javax.xml.bind.annotation.XmlAccessorType(javax.xml.bind.annotation.XmlAccessType.FIELD)
@javax.xml.bind.annotation.XmlType(name = "req", propOrder = {"myDetails", "customerDetails"})
public class Req  {
...
}

在我的应用程序中,我想简单地获取XML的String表示,以便我可以将其记录到文件中:

<Req>
    <MyDetails>
    ...
    </MyDetails>
    <CustomerDetails>
    ...
    </CustomerDetails>
</Req>

当我尝试使用JAXB和Marshall转换为XML String时:

JAXBContext context = JAXBContext.newInstance(Req.class);
Marshaller marshaller = context.createMarshaller();
StringWriter sw = new StringWriter();
marshaller.marshal(instanceOfReq, sw);
String xmlString = sw.toString();

我得到以下异常:

javax.xml.bind.MarshalException
    - with linked exception:
    [com.sun.istack.SAXException2: unable to marshal type "mypackage.Req" as an element because it is missing an @XmlRootElement annotation]

我查看了第三方库中的其他类,但没有一个使用@XmlRootElement注释.有什么方法吗？

Answer 1

您可以使用JAXB并将其编组为xml字符串

JAXBContext context = JAXBContext.newInstance(Req.class);
Marshaller marshaller = context.createMarshaller();
StringWriter sw = new StringWriter();
marshaller.marshal(instanceOfReq, sw);

String xmlString = sw.toString();

Answer 2

添加到Bala R指示的内容,如果您的JAXB元素没有,则可以执行此操作 @xmlrootelement

JAXBContext context = JAXBContext.newInstance(YourClass.class);
            Marshaller marshaller = context.createMarshaller();
            marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);
            StringWriter sw = new StringWriter();
            JAXBElement jx = new JAXBElement(new QName("YourRootElement"), YourClass.class, input);
            marshaller.marshal(jx, sw);
            String xmlString = sw.toString();

这也在这里说.