JDK11 - 如何在解组期间忽略命名空间答案

【问题标题】：JDK11 - How to ignore namespaces during unmarshallingJDK11 - 如何在解组期间忽略命名空间
【发布时间】：2023-03-11 10:19:01
【问题描述】：

我正在尝试编写一个 Java 11 XML 解组器，它在将命名空间数据转换为对象之前将其剥离，但出现以下错误。应用程序需要先从所有元素中剥离出前面的app:，然后才能被强制转换为 Object。

如何使用 JDK11 做到这一点？

错误

javax.xml.bind.UnmarshalException
 - with linked exception:
[com.sun.istack.SAXParseException2; lineNumber: 2; columnNumber: 67; unexpected element (uri:"", local:"app:exampleXML"). Expected elements are <{http://www.example.com/schemas/app}object>]
    at com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallerImpl.handleStreamException(UnmarshallerImpl.java:453)
    at com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal0(UnmarshallerImpl.java:387)
    at com.sun.xml.bind.v2.runtime.unmarshaller.UnmarshallerImpl.unmarshal(UnmarshallerImpl.java:356)
    XmlUnmarshaller.unmarshal(XmlUnmarshaller.java:36)
    ...
    at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: com.sun.istack.SAXParseException2; lineNumber: 2; columnNumber: 67; unexpected element (uri:"", local:"app:exampleXML"). Expected elements are <{http://www.example.com/schemas/app}object>
    ...
    ... 20 more
Caused by: javax.xml.bind.UnmarshalException: unexpected element (uri:"", local:"app:exampleXML"). Expected elements are <{http://www.example.com/schemas/app}object>
    ... 31 more

测试

public void testUnmarshal() throws JAXBException, XMLStreamException {

        String xml3 = "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?>\n" +
                "<app:exampleXML xmlns:app=\"http://www.example.com/schemas/app\">\n" +
                "<app:id>app-id</app:id>\n" +
                "<app:time>2020-06-05T13:17:00.899Z</app:time>\n" +
                "<app:type>test</app:type>\n" +
                "<app:description>Test</app:description>\n" +
                "</app:exampleXML>";

        XmlUnmarshaller unmarshaller = new XmlUnmarshaller();
        Object object = unmarshaller.unmarshal(xml3, Object.class);

        System.out.println(object);
}

解组器

public <T> T unmarshal(String xml, Class<T> clazz) throws JAXBException, XMLStreamException {
        JAXBContext jc = JAXBContext.newInstance(clazz);
        XMLInputFactory xif = XMLInputFactory.newFactory();
        xif.setProperty(XMLInputFactory.IS_NAMESPACE_AWARE, false);
        StreamSource source = new StreamSource(new StringReader(xml));
        XMLStreamReader xsr = xif.createXMLStreamReader(source);
        return clazz.cast(unmarshaller.unmarshal(xsr));
}

对象

@XmlRootElement(name = "exampleXML", namespace="http://www.example.com/schemas/app")
@XmlAccessorType(XmlAccessType.FIELD)
public class XML {
    public static final int DESCRIPTION_LENGTH = 4000;

    @XmlElement(name = "id", required = true)
    private String id;


    @XmlElement(name = "time", required = true)
    @XmlJavaTypeAdapter(InstantXmlAdapter.class)
    @JsonSerialize(using = InstantJsonSerializer.class)
    @JsonDeserialize(using = InstantJsonDeserializer.class)
    private Instant time;

    @XmlElement(name = "type", required = true)
    private CheckpointLevel type;

    @XmlElement(name = "description")
    @XmlJavaTypeAdapter(CDATAXmlAdapter.class)
    private String description;

【问题讨论】：

将app命名空间与默认绑定相同。
@ThorbjørnRavnAndersen 你这是什么意思？我已经在对象上的XMLRootElement 中分配了命名空间（请参阅更新）
请解释您为什么要这样做。编写使用命名空间的 Java 代码很容易。
@kimbert 因为解组仅适用于没有 app: 命名空间的 XML。有没有更好的方法在维护命名空间的同时将此 xml 数据强制转换为我的对象？

标签： java xml jaxb unmarshalling java-11

【解决方案1】：

在域对象中添加package-info.java并添加前缀

@XmlSchema(
        namespace = "http://www.example.com/schemas/app",
        elementFormDefault = XmlNsForm.QUALIFIED,
        xmlns = {
                @XmlNs(prefix = "app", namespaceURI = "http://www.example.com/schemas/app")
        }
)
package com.app.domainObjects;

import javax.xml.bind.annotation.XmlNs;
import javax.xml.bind.annotation.XmlNsForm;
import javax.xml.bind.annotation.XmlSchema;

【讨论】：