java - 无法使用 @XmlElementWrapper 解码与父元素具有相同名称的 XML 相同元素列表

Question

我有一个如下所示的 XML 文档，并希望对其执行解码

    <?xml version="1.0" encoding="UTF-8"?>
<SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:SOAP-ENC="http://schemas.xmlsoap.org/soap/encoding/"
    xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:sh="http://www.w3.org/2001/XMLSchema-instance">
    <SOAP-ENV:Body>
        <people xmlns="http://ccm.intra.bt.com/manageServiceFault/2006/06"
            xmlns:cds="http://capabilities.nat.bt.com/xsd/manageServiceFault/2010/06/Contact/Details"
            xmlns:sh="http://wsi.nat.bt.com/2005/06/StandardHeader/"
            xsi:schemaLocation="http://ccm.intra.bt.com/manageServiceFault/2006/06 MSF_5.0.xsd">
            <cds:address>
                <cds:Address>
                    <cds:postTown>London</cds:postTown>
                    <cds:postCode>WC2E 7AT</cds:postCode>
                    <cds:thoroughfareName>Bow Street</cds:thoroughfareName>
                    <cds:dependentLocality>local123</cds:dependentLocality>
                    <cds:county>London</cds:county>
                    <cds:thoroughfareNumber>30-34</cds:thoroughfareNumber>
                    <cds:subPremise>2nd Floor</cds:subPremise>
                    <cds:buildingName>BT tower</cds:buildingName>
                    <cds:buildingNumber>Lot 1234</cds:buildingNumber>
                    <cds:locality>London</cds:locality>
                    <cds:premise>Covent Garden Exchange</cds:premise>
                    <cds:dependentThoroughfare>345</cds:dependentThoroughfare>
                    <cds:poBox>PO1234</cds:poBox>
                </cds:Address>
                <cds:Address>
                    <cds:postTown>New York</cds:postTown>
                    <cds:postCode>WC2E 7AT</cds:postCode>
                    <cds:thoroughfareName>Bow Street</cds:thoroughfareName>
                    <cds:dependentLocality>local123</cds:dependentLocality>
                    <cds:county>US</cds:county>
                    <cds:thoroughfareNumber>30-34</cds:thoroughfareNumber>
                    <cds:subPremise>2nd Floor</cds:subPremise>
                    <cds:buildingName>BT tower</cds:buildingName>
                    <cds:buildingNumber>Lot 1234</cds:buildingNumber>
                    <cds:locality>US</cds:locality>
                    <cds:premise>Covent Garden Exchange</cds:premise>
                    <cds:dependentThoroughfare>345</cds:dependentThoroughfare>
                    <cds:poBox>PO1234</cds:poBox>
                </cds:Address>
                <cds:country>
                    <cds:name>UK</cds:name>
                </cds:country>
                <cds:country>
                    <cds:name>US</cds:name>
                </cds:country>
            </cds:address>
        </people>
    </SOAP-ENV:Body>
</SOAP-ENV:Envelope>

请注意，元素地址包含一个或多个地址和国家/地区元素。地址和地址相同，只是 A 不同。以下是我的域类

People2.java

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.XmlType;

@XmlRootElement(name = "people")
@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(namespace = "http://capabilities.nat.bt.com/xsd/manageServiceFault/2010/06/Contact/Details")
public class People2 {

    @XmlElement(name = "address")
    private Addresses addresses;

    public Addresses getAddresses() {
        return addresses;
    }

    public void setAddresses(Addresses addresses) {
        this.addresses = addresses;
    }

}

地址.java

import java.util.ArrayList;
import java.util.List;

import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlElementWrapper;
import javax.xml.bind.annotation.XmlType;

@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(namespace = "http://capabilities.nat.bt.com/xsd/manageServiceFault/2010/06/Contact/Details")
public class Addresses {

    @XmlElementWrapper(name = "address")
    @XmlElement(name = "Address")
    private List<Address> address;

    @XmlElementWrapper(name = "address")
    @XmlElement(name = "country")
    private List<Country> country;

    public Addresses() {
        address = new ArrayList<Address>();
        country = new ArrayList<Country>();
    }

    public List<Address> getAddress() {
        return address;
    }

    public void setAddress(List<Address> address) {
        this.address = address;
    }

    public List<Country> getCountry() {
        return country;
    }

    public void setCountry(List<Country> country) {
        this.country = country;
    }

}

下面是我解码 XML 的主要代码

import java.beans.IntrospectionException;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.List;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;
import javax.xml.bind.Unmarshaller;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamConstants;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;

public class Demo2 {

    public static void main(String[] args) throws FileNotFoundException, XMLStreamException, JAXBException,
            IllegalAccessException, IllegalArgumentException, InvocationTargetException, IntrospectionException {

        XMLInputFactory xif = XMLInputFactory.newInstance();
        XMLStreamReader xsr = xif.createXMLStreamReader(new FileReader("./xml/Testing2.xml"));

        JAXBContext jc = JAXBContext.newInstance(People2.class);
        Unmarshaller unmarshaller = jc.createUnmarshaller();

        xsr.nextTag();
        System.out.println("Current XML element: " + xsr.getLocalName());

        xsr.nextTag();
        System.out.println("Current XML element: " + xsr.getLocalName());

        int tag = xsr.nextTag();
        if (tag == XMLStreamConstants.START_ELEMENT) {
            System.out.println("Current XML element: " + xsr.getLocalName());

            People2 people = (People2) unmarshaller.unmarshal(xsr);

            for (PropertyDescriptor propertyDescriptor : Introspector.getBeanInfo(People2.class, Object.class)
                    .getPropertyDescriptors()) {
                Method method = propertyDescriptor.getReadMethod();
                System.out.println("Class name: " + people.getClass().getSimpleName() + ", Method: " + method.getName()
                        + ", Value: " + method.invoke(people));
            }

            Addresses addresses = people.getAddresses();
            for (PropertyDescriptor propertyDescriptor : Introspector.getBeanInfo(Addresses.class, Object.class)
                    .getPropertyDescriptors()) {
                Method method = propertyDescriptor.getReadMethod();
                System.out.println("Class name: " + addresses.getClass().getSimpleName() + ", Method: "
                        + method.getName() + ", Value: " + method.invoke(addresses));

            }

        }
    }

}

问题是，当在 Addresses 中打印方法时，getAddress 和 getCountry 的值返回 null，如下所示。看来绑定(bind)没有发生。

Current XML element: Envelope
Current XML element: Body
Current XML element: people
Class name: People2, Method: getAddresses, Value: com.bt.platform.automation.domain.Addresses@433c675d
Class name: Addresses, Method: getAddress, Value: []
Class name: Addresses, Method: getCountry, Value: []

如果我在Addresses.java中删除这个@XmlElementWrapper(name = "address")，它的工作原理如下

Current XML element: Envelope
Current XML element: Body
Current XML element: people
Class name: People2, Method: getAddresses, Value: com.bt.platform.automation.domain.Addresses@2e817b38
Class name: Addresses, Method: getAddress, Value: [com.bt.platform.automation.domain.Address@c4437c4, com.bt.platform.automation.domain.Address@433c675d]
Class name: Addresses, Method: getCountry, Value: [com.bt.platform.automation.domain.Country@3f91beef, com.bt.platform.automation.domain.Country@1a6c5a9e]

任何人都可以帮忙，如果我不删除 @XmlElementWrapper(name = "address")，为什么它不能按预期工作？我引用过这篇文章 - http://blog.bdoughan.com/2010/09/jaxb-collection-properties.html但它似乎不适用于我的代码。

Answer 1

我认为您误解了 @XmlElementWrapper 的用途。

为了举例，假设您的地址元素仅包含 Address 元素。

然后您可以使用以下代码，并删除 Adresses 类的必要性:

@XmlRootElement(name = "people")
@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(namespace = "http://capabilities.nat.bt.com/xsd/manageServiceFault/2010/06/Contact/Details")
public class People2 {

    @XmlElement(name = "Address")
    @XmlElementWrapper(name = "address")
    private List<Address> addresses;

    public List<Address> getAddresses() {
        return addresses;
    }

    public void setAddresses(List<Address> addresses) {
        this.addresses = addresses;
    }

}

@XmlElementWrapper 的存在就是为了这个目的，因为我们倾向于在给定元素的列表周围放置一个包装器元素，因此它将强制使用中间类。