我有几个 XSD，我通过 XJC 创建了 Java 代码。我可以通过 XJC 提供的“直接映射”POJOs 获得很多信息。其余大部分可以通过 JAXBElements 检索。但是，有一些元素我不知道如何与他们交谈，即“交易/描述”父项下的“成本”元素。
<transaction>
<aid-type code="1995-09-25"/>
<flow-type code="10">ODA</flow-type>
<provider-org ref="DE-1">BMZ</provider-org>
<value currency="EUR" value-date="1995-09-25">2070227</value>
<transaction-type code="D">Disbursement</transaction-type>
<description type="1" xml:lang="en">
<costs currency="EUR" type="Personnel costs">1060135</costs>
<costs currency="EUR" type="Material costs">665117</costs>
<costs currency="EUR" type="Other costs">344975</costs>
</description>
</transaction>
如您所见，Transaction.java 包含“description”元素并将其映射到 JAXBElement.class。
@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "", propOrder = {
"valueOrDescriptionOrTransactionType"
})
@XmlRootElement(name = "transaction")
public class Transaction {
@XmlElementRefs({
@XmlElementRef(name = "transaction-date", type = JAXBElement.class, required = false),
@XmlElementRef(name = "value", type = JAXBElement.class, required = false),
@XmlElementRef(name = "disbursement-channel", type = JAXBElement.class, required = false),
@XmlElementRef(name = "receiver-org", type = JAXBElement.class, required = false),
@XmlElementRef(name = "transaction-type", type = JAXBElement.class, required = false),
@XmlElementRef(name = "description", type = JAXBElement.class, required = false),
@XmlElementRef(name = "tied-status", type = JAXBElement.class, required = false),
@XmlElementRef(name = "aid-type", type = JAXBElement.class, required = false),
@XmlElementRef(name = "finance-type", type = JAXBElement.class, required = false),
@XmlElementRef(name = "provider-org", type = JAXBElement.class, required = false),
@XmlElementRef(name = "flow-type", type = JAXBElement.class, required = false)
})
@XmlAnyElement(lax = true)
protected List<Object> valueOrDescriptionOrTransactionType;
@XmlAttribute(name = "ref")
protected String ref;
@XmlAnyAttribute
private Map<QName, String> otherAttributes = new HashMap<QName, String>();
在 Transaction.java 之上，模式片段说：
...
<element name="description" type="{}textType"/>
...
所以“描述”的类型应该是 JAXBElement<TextType>。TextType.java 如下所示：
@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "textType", propOrder = {"content"})
public class TextType {
@XmlMixed
@XmlAnyElement(lax = true)
protected List<Object> content;
@XmlAttribute(name = "lang", namespace = "http://www.w3.org/XML/1998/namespace")
protected String lang;
@XmlAnyAttribute
private Map<QName, String> otherAttributes = new HashMap<QName, String>();
现在要从事务中获取信息，我构建了一个事务对象并检索它的内容：
List<Object> listOfTransactionContents = transaction.getValueOrDescriptionOrTransactionType();
这给了我一个列表，我在其中查找 JAXBElement 对象。
for (Object obj : listOfTransactionContents)
{
JAXBElement<TextType> jaxbElementTextType = (JAXBElement<TextType>) obj;
TextType textType = jaxbElementTextType.getValue();
List<Object> listOftTextTypes = textType.getContent();
....
但这里的问题是我现在不知道如何获取“成本”元素的内容。在 TextType.java 的 getContent() 方法之上，它说：
* Objects of the following type(s) are allowed in the list
* {@link Element }
* {@link String }
* {@link Object }
“成本”元素的内容必须存储在某种列表中，因为“描述”父元素下可以有多个。