JAXB 编组器使用 Java 成员变量约定

Question

I'm currently trying to figure out why JAXB marshaller uses Java member variable convention as opposed to follow the XmlType annotation.

Here's the situation:

• Third-party gave us XSD
• We use JDK tools to generate Java classes
• The generated Java classes produced correct annotation: @XmlType(name = "XML_DOCUMENT_TYPE")

But when I tried to marshal the class back to XML, JAXB converts it to <xmlDocumentType> instead of <XML_DOCUMENT_TYPE>

Any idea why? (If so, how can I fix this?)

Update: to clarify, the issue occurred at the top/root level element, not at the sub element/member variable.

Answer 1

UPDATE (based on comment by xandross

You can use @XmlRootElement to control the root element name:

@XmlRootElement(name="XML_DOCUMENT_TYPE")
public class Foo {
  ...
}

Alternatively you can wrap the root object in an instance of JAXBElement to supply root element information.

---

UPDATE (based on comment by Mohamed Mansour)

In JAXB classes correspond to XML types, and fields/properties correspond to XML attributes/elements. This makes sense when you consider there may exist an address type:

<xs:complexType name="address">
    <xs:sequence>
        <xs:element name="street" type="xs:string"/>
    </xs:sequence>
</xs:complexType>

and multiple elements (with different names) that are of that type:

<xs:complexType name="customer">
    <xs:sequence>
        <xs:element name="billing-address type="address"/>
        <xs:element name="shipping-address type="address"/>
    </xs:sequence>
</xs:complexType>

You can control the name of the element/attribute that a property maps to with the @XmlElement / @XmlAttribute annotations:

@XmlElement(name="shipping-address")
public getShippingAddress() {
    return shippingAddress;
}

or

@XmlElement(name="ShippingAddress")
public getShippingAddress() {
    return shippingAddress;
}

If the property is not annotated it is treated as @XmlElement and the element name is derived from the property name.