JAXB：属性中的 XMLIDRef？

Question

我有一个如下所示的 XML：

<MyClass id="abc-123">
   <SomeAttribute idref="cde-456" />
</MyClass>

<SomeOtherClass id="cde-456">

并想使用 JAXB / Moxy 绑定它。到目前为止我能达到的最好成绩是

 @XmlIDREF
 @XmlElement(name="SomeAttribute ")
 //@XmlPath("SomeAttribute /@idref")
 protected SomeOtherClass someAttribute ;

但这只给出<SomeAttribute>cde-456</SomeAttribute>

任何想法，idref 属性的绑定可能如何工作？ @XmlPath 不起作用。

Answer 1

这应该适合你：

XML：

<root>
    <MyClass id="abc-123">
        <SomeAttribute idref="cde-456"/>
    </MyClass>
    <SomeOtherClass id="cde-456"/>
</root>

根：

@XmlRootElement(name = "root")
@XmlAccessorType(XmlAccessType.FIELD)
@Data
public class Root {
    private MyClass MyClass;
    private SomeOtherClass SomeOtherClass;
}

我的班级：

@XmlAccessorType(XmlAccessType.FIELD)
@Data
public class MyClass {
    @XmlAttribute
    private String id;
    private SomeAttribute SomeAttribute;
}

一些属性：

@XmlAccessorType(XmlAccessType.FIELD)
@Data
public class SomeAttribute {
    @XmlAttribute
    private String idref;
}

SomeOtherClass：

@XmlAccessorType(XmlAccessType.FIELD)
@Data
public class SomeOtherClass {
    @XmlAttribute
    private String id;
}

主要：

public class Main {
    public static void main(String[] args) throws JAXBException, XMLStreamException {
        final InputStream inputStream = Main.class.getClassLoader().getResourceAsStream("sample.xml");
        final XMLStreamReader xmlStreamReader = XMLInputFactory.newInstance().createXMLStreamReader(inputStream);
        final Unmarshaller unmarshaller = JAXBContext.newInstance(Root.class).createUnmarshaller();
        final Root root = unmarshaller.unmarshal(xmlStreamReader, Root.class).getValue();
        System.out.println(root.toString());

        Marshaller marshaller = JAXBContext.newInstance(Root.class).createMarshaller();
        marshaller.setProperty(Marshaller.JAXB_FRAGMENT, Boolean.TRUE);
        marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);
        marshaller.marshal(root, System.out);
    }
}

输出：

Root(MyClass=MyClass(id=abc-123, SomeAttribute=SomeAttribute(idref=cde-456)), SomeOtherClass=SomeOtherClass(id=cde-456))
<root>
   <MyClass id="abc-123">
      <SomeAttribute idref="cde-456"/>
   </MyClass>
   <SomeOtherClass id="cde-456"/>
</root>

Answer 2

现在我解决了一个小例子，现实世界还有待完成:-)

1. 使用 Moxy 并将 jaxb.properties 添加到该包的资源中。 javax.xml.bind.context.factory=org.eclipse.persistence.jaxb.JAXBContextFactory
2. 根类

@XmlAccessorType(XmlAccessType.FIELD)
public class Root {
    @XmlElement(name="MyClass")
    MyClass myClass;

    @XmlElement(name="SomeOtherClass")
    List<SomeOtherClass> someOtherClasses = new ArrayList<>();
}

1. 我的班级

@XmlAccessorType(XmlAccessType.FIELD)
public class MyClass {
    @XmlID
    @XmlPath("@id")
    String id = UUID.randomUUID().toString();
    @XmlIDREF
    @XmlPath("SomeAttribute/@idref")
    SomeOtherClass someAttribute;
    @XmlElement(name = "Name")
    String name;
}

4. SomeOtherClass

@XmlSeeAlso({DerivedClass.class})
@XmlAccessorType(XmlAccessType.FIELD)
public class SomeOtherClass {
    @XmlID
    @XmlPath("@id")
    String id = UUID.randomUUID().toString();
    @XmlElement(name="Name")
    String name;
}

5. 派生类

@XmlType(name = "DerivedClass")
@XmlAccessorType(XmlAccessType.FIELD)
public class DerivedClass extends SomeOtherClass{
    String inDerived;
}

现在我可以加载和写这个了：

<root xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
   <MyClass id="64c80ae9-1d2b-4b79-98d1-0dfe0915f6a2">
      <SomeAttribute idref="335f0edb-6873-4acc-8c49-2c92cf6b3fcd"/>
      <Name>CDE</Name>
   </MyClass>
   <SomeOtherClass id="23a0dee0-fe06-45cc-a280-efb4a4bad345">
      <Name>ABC</Name>
   </SomeOtherClass>
   <SomeOtherClass id="335f0edb-6873-4acc-8c49-2c92cf6b3fcd" xsi:type="DerivedClass">
      <Name>FGH</Name>
      <inDerived>IJK</inDerived>
   </SomeOtherClass>
</root>