我正在尝试在更大的文档中映射以下XML结构，显然这不是XML的最大用途，但这是我必须使用的。
为简化起见，简化了示例：
<details>
<pictures>
<picture1>
http://domain.com/path/picture1.jpg
</picture1>
<picture2>
http://domain.com/path/picture2.jpg
</picture2>
<picture3>
http://domain.com/path/picture3.jpg
</picture3>
<picture4>
http://domain.com/path/picture4.jpg
</picture4>
<picture5>
http://domain.com/path/picture5.jpg
</picture5>
<picture6>
http://domain.com/path/picture6.jpg
</picture6>
<picture7>
http://domain.com/path/picture7.jpg
</picture7>
</pictures>
</details>
此文档有一个DTD，声明最多可有30个不同的图片元素，编号为1-30，名称为<picutre[n]/>
我想做的是，而不是为这些元素创建30个不同的类，分别称为Picture1，Picture2，Picture3 ......等等。我只想使用一个Picture类并将其用于所有30个唯一元素名称。
以下是我到目前为止所尝试的内容。
@XmlRootElement
public class Details {
...
@XmlElementWrapper
@XmlElementRefs({
@XmlElementRef( name="picture1", type=Picture.class ),
@XmlElementRef( name="picture2", type=Picture.class ),
@XmlElementRef( name="picture3", type=Picture.class ),
@XmlElementRef( name="picture4", type=Picture.class ),
@XmlElementRef( name="picture5", type=Picture.class ),
@XmlElementRef( name="picture6", type=Picture.class ),
@XmlElementRef( name="picture7", type=Picture.class ),
@XmlElementRef( name="picture8", type=Picture.class ),
@XmlElementRef( name="picture9", type=Picture.class ),
@XmlElementRef( name="picture10", type=Picture.class ),
@XmlElementRef( name="picture11", type=Picture.class ),
@XmlElementRef( name="picture12", type=Picture.class ),
@XmlElementRef( name="picture13", type=Picture.class ),
@XmlElementRef( name="picture14", type=Picture.class ),
@XmlElementRef( name="picture15", type=Picture.class ),
@XmlElementRef( name="picture16", type=Picture.class ),
@XmlElementRef( name="picture17", type=Picture.class ),
@XmlElementRef( name="picture18", type=Picture.class ),
@XmlElementRef( name="picture19", type=Picture.class ),
@XmlElementRef( name="picture20", type=Picture.class ),
@XmlElementRef( name="picture21", type=Picture.class ),
@XmlElementRef( name="picture22", type=Picture.class ),
@XmlElementRef( name="picture23", type=Picture.class ),
@XmlElementRef( name="picture24", type=Picture.class ),
@XmlElementRef( name="picture25", type=Picture.class ),
@XmlElementRef( name="picture26", type=Picture.class ),
@XmlElementRef( name="picture27", type=Picture.class ),
@XmlElementRef( name="picture28", type=Picture.class ),
@XmlElementRef( name="picture29", type=Picture.class ),
@XmlElementRef( name="picture30", type=Picture.class )
})
public List<Picture> getPictures() {
return this.pictures;
}
public void setPictures( List<Pictures> pictures ) {
this.pictures = pictures;
}
...
}
@XmlElementWrapper
public class Picture {
...
}
这会导致getPictures始终返回null。
此外，我尝试将Picture类的注释更改为@XmlElementWrapper( name="picture1" )，这导致我从getPictures（）返回一个列表，但只包含<picture1/>元素，而不是其余元素。
我知道我可以求助于获取JAXBElement对象列表，但如果可以避免它，我宁愿不这样做。我有什么想法可以映射这个吗？
答案 0 :(得分：5)
有几种方法可以处理这个用例：
选项＃1
您可以通过利用@XmlElements：
package forum10109418;
import java.util.List;
import javax.xml.bind.annotation.*;
@XmlRootElement
public class Details {
private List<Picture> pictures;
@XmlElementWrapper
@XmlElements({
@XmlElement( name="picture1", type=Picture.class ),
@XmlElement( name="picture2", type=Picture.class ),
@XmlElement( name="picture3", type=Picture.class ),
@XmlElement( name="picture4", type=Picture.class ),
@XmlElement( name="picture5", type=Picture.class ),
@XmlElement( name="picture6", type=Picture.class ),
@XmlElement( name="picture7", type=Picture.class ),
@XmlElement( name="picture8", type=Picture.class ),
@XmlElement( name="picture9", type=Picture.class ),
@XmlElement( name="picture10", type=Picture.class ),
@XmlElement( name="picture11", type=Picture.class ),
@XmlElement( name="picture12", type=Picture.class ),
@XmlElement( name="picture13", type=Picture.class ),
@XmlElement( name="picture14", type=Picture.class ),
@XmlElement( name="picture15", type=Picture.class ),
@XmlElement( name="picture16", type=Picture.class ),
@XmlElement( name="picture17", type=Picture.class ),
@XmlElement( name="picture18", type=Picture.class ),
@XmlElement( name="picture19", type=Picture.class ),
@XmlElement( name="picture20", type=Picture.class ),
@XmlElement( name="picture21", type=Picture.class ),
@XmlElement( name="picture22", type=Picture.class ),
@XmlElement( name="picture23", type=Picture.class ),
@XmlElement( name="picture24", type=Picture.class ),
@XmlElement( name="picture25", type=Picture.class ),
@XmlElement( name="picture26", type=Picture.class ),
@XmlElement( name="picture27", type=Picture.class ),
@XmlElement( name="picture28", type=Picture.class ),
@XmlElement( name="picture29", type=Picture.class ),
@XmlElement( name="picture30", type=Picture.class )
})
public List<Picture> getPictures() {
return this.pictures;
}
public void setPictures( List<Picture> pictures ) {
this.pictures = pictures;
}
}
选项＃2
您可以按如下方式映射Details课程：
package forum10109418;
import java.util.List;
import javax.xml.bind.annotation.*;
@XmlRootElement
public class Details {
private List<Picture> pictures;
@XmlElementWrapper
@XmlElement(name="picture")
public List<Picture> getPictures() {
return this.pictures;
}
public void setPictures( List<Picture> pictures ) {
this.pictures = pictures;
}
}
然后使用StreamReaderDelegate来删除数字后缀：
package forum10109418;
import java.io.FileInputStream;
import javax.xml.bind.*;
import javax.xml.stream.*;
import javax.xml.stream.util.StreamReaderDelegate;
public class Demo {
public static void main(String[] args) throws Exception {
JAXBContext jc = JAXBContext.newInstance(Details.class);
XMLInputFactory xif = XMLInputFactory.newFactory();
XMLStreamReader xsr = xif.createXMLStreamReader(new FileInputStream("src/forum10109418/input.xml"));
xsr = new StreamReaderDelegate(xsr) {
@Override
public String getLocalName() {
String localName = super.getLocalName();
if(localName.startsWith("picture") && !localName.equals("pictures")) {
return "picture";
}
return localName;
}
};
Unmarshaller unmarshaller = jc.createUnmarshaller();
Details details = (Details) unmarshaller.unmarshal(xsr);
System.out.println(details.getPictures().size());
}
}
选项＃3
如果您使用EclipseLink MOXy作为JAXB (JSR-222)提供商，则可以使用我们添加的@XmlVariableNode扩展程序：