使用JAXB处理设计不佳的XML [英] Dealing with poorly designed XML with JAXB

问题描述

我目前正在使用JAXB替换遗留系统，而且我在解析XML时遇到了问题。系统的首要要求是它必须是替代品，因此我无法修改XML的格式。以下是给我带来麻烦的XML部分。

I'm currently working on replacing a legacy system with JAXB and I'm running into problem with parsing the XML. The number one requirement of the system is that it must be a drop-in replacement so I cannot modify the format of the XML. Below is the XML section that is giving me trouble.

<xx>
    <s1>
        <X>-9999</X>
        <Y>-9999</Y>
    </s1>
    <s2>
        <X>-9999</X>
        <Y>-9999</Y>
   </s2>
</xx>

XML的问题是所有s＃对象都是完全相同的并且可以存在最多256个。在JAXB中有一种方法可以注释这样的标记，还是我必须创建256个单独的注释？任何帮助都将非常受欢迎。

The issue with the XML is that all of the s# objects are the exact same and there can be up to 256 of them. Is there a way in JAXB to annotate such a tag or do I have to create 256 separate annotations? Any help would be most appreciated.

这是xx对象的java代码。注意：该对象最初编程时理解只有2个s＃对象，但之后已经改变。

Here is the java code for the xx object. Note: the object was originally programmed with the understanding that there would only be 2 s# objects, but that since has changed.

@XmlRootElement(name="xx")

public class XMLXx implements Serializable {

    private static final long serialVersionUID = 4064597372833234503L;

    private XMLSite siteOne;
    private XMLSite siteTwo;

    @XmlElement(name="s1")
    public XMLSite getSiteOne() {
        return siteOne;
    }

    public void setSiteOne(XMLSite s1) {
        this.siteOne = s1;
    }

    @XmlElement(name="s2")
    public XMLSite getSiteTwo() {
        return siteTwo;
    }

    public void setSiteTwo(XMLSite s2) {
        this.siteTwo = s2;
    }
}

这是XMLSite对象：

And here is the XMLSite object:

public class XMLSite implements Serializable {

    private static final long serialVersionUID = -4374405403222014476L;

    private Integer x;
    private Integer y;

    @XmlElement(name="X")
    public Integer getX() {
        return x;
    }

    public void setX(Integer x) {
        this.x = x;
    }

    @XmlElement(name="Y")
    public Integer getY() {
        return y;
    }

    public void setY(Integer y) {
        this.y = y;
    }
}

推荐答案

如果您希望将 s＃项目作为集合处理：

If you want to handle at the s# items as a collection:

import java.io.Serializable;
import java.util.List;

import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;

@XmlRootElement(name="xx")
public class XMLXx implements Serializable {

    private static final long serialVersionUID = 4064597372833234503L;

    private List<XMLSite> sites;

    @XmlElement(name="s")
    public List<XMLSite> getSites() {
        return sites;
    }

    public void setSites(List<XMLSite> sites) {
        this.sites = sites;
    }

}

然后你可以做类似的事情愚弄JAXB认为所有元素（ s1 ， s2 等）实际上都被称为 s ：

Then you could do something like to fool JAXB into thinking all the elements (s1, s2, etc) are actually called s:

import java.io.FileInputStream;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.Unmarshaller;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamReader;
import javax.xml.stream.util.StreamReaderDelegate;

public class Demo {

    public static void main(String[] args) throws Exception {
        JAXBContext jc = JAXBContext.newInstance(XMLXx.class);

        XMLInputFactory xif = XMLInputFactory.newInstance();
        XMLStreamReader xsr = xif.createXMLStreamReader(new FileInputStream("input.xml"));
        xsr = new SiteStreamReaderDelegate(xsr);

        Unmarshaller unmarshaller = jc.createUnmarshaller();
        XMLXx object = (XMLXx) unmarshaller.unmarshal(xsr);
        System.out.println(object.getSites().size());

    }

    private static class SiteStreamReaderDelegate extends StreamReaderDelegate {

        public SiteStreamReaderDelegate(XMLStreamReader xsr) {
            super(xsr);
        }

        @Override
        public String getLocalName() {
            String localName = super.getLocalName();
            if(localName.startsWith("s")) {
                return "s";
            }
            return localName;
        }

    }
}

类似的例子见：

• http://bdoughan.blogspot.com/2010/12/case-insensitive-unmarshalling.html

• http://bdoughan.blogspot.com/2010/12/case-insensitive-unmarshalling.html

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