JAXB/XSD:Number而不是Element name

我想你的 XML 有效载荷如下:

<root>
    <parent-element>
        <id-00001>value 1</id-00001>
        <id-00002>value 2</id-00002>
    </parent-element>
</root>

要读取具有动态名称的节点,我们需要编写自定义适配器( javax.xml.bind.annotation.adapters.XmlAdapter

@XmlRootElement(name = "root")
@XmlAccessorType(XmlAccessType.FIELD)
class Root {

    @XmlElement(name = "parent-element")
    @XmlJavaTypeAdapter(IdsXmlAdapter.class)
    private MultiItemList list;

    // getters, setters, toString
}

class MultiItemList {

    private List<String> ids;

    // getters, setters, toString
}

对于以上 XML格式 POJO 模型自定义适配器可能如下所示:

class IdsXmlAdapter extends XmlAdapter<Object, MultiItemList> {

    @Override
    public MultiItemList unmarshal(Object v) {
        Element element = (Element) v;
        NodeList childNodes = element.getChildNodes();
        List<String> ids = new ArrayList<>(childNodes.getLength());
        for (int i = 0; i < childNodes.getLength(); i++) {
            Node item = childNodes.item(i);
            if (item.getNodeName().equals("#text")) {
                continue;
            }
            ids.add(item.getTextContent());
        }

        MultiItemList multiItemList = new MultiItemList();
        multiItemList.setIds(ids);
        return multiItemList;
    }

    @Override
    public Object marshal(MultiItemList v) throws Exception {
        return null; // Implement if needed
    }
}

import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.adapters.XmlAdapter;
import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;
import java.io.File;
import java.io.FileReader;
import java.util.ArrayList;
import java.util.List;

public class JaxbApp {

    public static void main(String[] args) throws Exception {
        File xmlFile = new File("./resource/test.xml").getAbsoluteFile();

        JAXBContext jaxbContext = JAXBContext.newInstance(Root.class);

        Object unmarshal = jaxbContext.createUnmarshaller().unmarshal(new FileReader(xmlFile));
        System.out.println(unmarshal);
    }
}

印刷品:

Root{list=Root{ids=[value 1, value 2]}}

XmlAdapter<Element, MultiItemList> 适配器由于异常:

Exception in thread "main" com.sun.xml.internal.bind.v2.runtime.IllegalAnnotationsException: 1 counts of IllegalAnnotationExceptions
org.w3c.dom.Element is an interface, and JAXB can't handle interfaces.
    this problem is related to the following location:
        at org.w3c.dom.Element

另见:

• Read XML body element having multiple values based on different requests

@XmlAnyElement 还有一个适配器。 @XmlAnyElement公司

例如,使用下面给出的xml:

<parent-element>
    <id-00001>value 1</id-00001>
    <id-00002>value 2</id-00002>
</parent-element>

你的根可能是这样的:

@XmlRootElement(name = "parent-element")
@XmlAccessorType(XmlAccessType.FIELD)
public class Root {

    @XmlAnyElement
    @XmlJavaTypeAdapter(MyAdapter.class)
    private List<String> varyingElements;

}

你的适配器是这样的:

public class MyAdapter extends XmlAdapter<Element, String> {

    @Override
    public Element marshal(String arg0) throws Exception {
        // do what you must
        return null;
    }

    @Override
    public String unmarshal(Element element) throws Exception {
        return element.getChildNodes().item(0).getNodeValue();
    }

}

org.w3c.dom.Element