Question

我正在研究配置XML文件，我希望它是动态的。

我有以下课程：

存储库：

@XmlAccessorType(XmlAccessType.FIELD)
@XmlRootElement(name = "repository")
public class Repository
        implements Serializable
{

    @XmlElement(name = "custom-configuration")
    private CustomConfiguration customConfiguration;

    ...
    // Constructor

    // Getters and setters
}

CustomConfiguration：

@XmlAccessorType(XmlAccessType.FIELD)
public class CustomConfiguration
{
}

FooBarConfiguration：

@XmlAccessorType(XmlAccessType.FIELD)
@XmlRootElement(name = "foo-bar-configuration")
public class FooBarConfiguration extends CustomConfiguration
{

    @XmlAttribute
    private String bucket;

    @XmlAttribute
    private String key;


    public FooBarConfiguration()
    {
    }

    public String getBucket()
    {
        return bucket;
    }

    public void setBucket(String bucket)
    {
        this.bucket = bucket;
    }

    public String getKey()
    {
        return key;
    }

    public void setKey(String key)
    {
        this.key = key;
    }

}

这就是我想要的：

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<repository id="test-repository">
    <foo-bar-configuration bucket="test-bucket" key="test-key"/>
    <group/>
</repository>

这就是我所得到的：

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<repository id="test-repository">
    <customConfiguration xsi:type="fooBarConfiguration" bucket="test-bucket" key="test-key" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"/>
    <group/>
</repository>

任何想法如何实现这一目标？

Answer 1

您应该能够使用@XmlElementRef按元素名称编组，例如：

@XmlElementRef
private CustomConfiguration customConfiguration;

以下是Blaise Doughan的一个例子：http://blog.bdoughan.com/2010/11/jaxb-and-inheritance-using-substitution.html

Javadoc：https://docs.oracle.com/javase/8/docs/api/javax/xml/bind/annotation/XmlElementRef.html

Answer 2

根据要求，这是一个真实的例子。

某些基本类型的

Schema declares and abstract element：

   <xsd:element name="AbstractQueryExpression"
                type="fes:AbstractQueryExpressionType" abstract="true"/>

This is how it's used：

   <xsd:complexType name="GetPropertyValueType">
      <xsd:complexContent>
         <xsd:extension base="wfs:BaseRequestType">
            <xsd:sequence>
               <xsd:element ref="fes:AbstractQueryExpression"/>
            </xsd:sequence>
            <xsd:attribute name="valueReference" type="xsd:string"
               use="required"/>
            <xsd:attribute name="resolvePath" type="xsd:string"/>
            <xsd:attributeGroup ref="wfs:StandardPresentationParameters"/>
            <xsd:attributeGroup ref="wfs:StandardResolveParameters"/>
         </xsd:extension>
      </xsd:complexContent>
   </xsd:complexType>

这导致以下Java代码：

@XmlElementRef(name = "AbstractQueryExpression", namespace = "http://www.opengis.net/fes/2.0", type = JAXBElement.class)
protected JAXBElement<?> abstractQueryExpression;

Another schema declares an element which may substitute the original element：

   <xsd:element name="StoredQuery" type="wfs:StoredQueryType"
      substitutionGroup="fes:AbstractQueryExpression"/>

在ObjectFactory中，如下所示：

@XmlElementDecl(namespace = "http://www.opengis.net/wfs/2.0", name = "StoredQuery", substitutionHeadNamespace = "http://www.opengis.net/fes/2.0", substitutionHeadName = "AbstractQueryExpression")
public JAXBElement<StoredQueryType> createStoredQuery(StoredQueryType value) {
    return new JAXBElement<StoredQueryType>(_StoredQuery_QNAME, StoredQueryType.class, null, value);
}

此机制可用于实现＆＃34;扩展点＆＃34;。您声明并使用抽象/通用＆＃34;替换头＆＃34;元素和其他模式中的特定元素可以替代它。

希望这有帮助。

JAXB继承dymanically命名标记

2 个答案: