If there are some @XmlID annotated properties with equal value, even they are of different type, JAXB could not unmarshall objects successfully, however marshall is good.
Is it a bug?
Or else, how to support that feature?
codes:
package xml;
import java.io.File;
import java.io.FileNotFoundException;
import java.util.ArrayList;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;
import javax.xml.bind.Unmarshaller;
import javax.xml.bind.annotation.*;
import javax.xml.bind.annotation.adapters.XmlAdapter;
import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;
public class MultiID {
static public class LongXmlAdapter extends XmlAdapter<String, Long> {
@Override
public Long unmarshal(String s) {
return Long.parseLong(s);
}
@Override
public String marshal(Long number) {
if (number == null) return "";
return number.toString();
}
}
static public class Element {
private Long id;
@XmlID
@XmlAttribute(required=true)
@XmlJavaTypeAdapter(LongXmlAdapter.class)
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
}
static public class Component {
private Long id;
@XmlID
@XmlAttribute(required=true)
@XmlJavaTypeAdapter(LongXmlAdapter.class)
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
private Element elem;
@XmlIDREF
@XmlAttribute(required=true)
public Element getElem() {
return elem;
}
public void setElem(Element e) {
this.elem = e;
}
}
@XmlRootElement
static public class Container {
private List<Element> elemLst = new ArrayList<Element>();
private List<Component> lst = new ArrayList<Component>();
@XmlElementWrapper(name="elemList")
@XmlElement(name="elem")
public List<Element> getElemLst() {
return (elemLst != null)?elemLst:(elemLst = new ArrayList<Element>());
}
public void setElemLst(List<Element> elemLst) {
this.elemLst = elemLst;
}
@XmlElementWrapper(name="componentList")
@XmlElement(name="component")
public List<Component> getLst() {
return (lst != null)?lst:(lst = new ArrayList<Component>());
}
public void setLst(List<Component> lst) {
this.lst = lst;
}
}
static public class XmlSerialization {
public static Object read(String filepath, Class... classesToBeBound) throws FileNotFoundException {
Object entity = null;
try {
File file = new File(filepath);
if(!file.exists()) throw new FileNotFoundException(filepath);
JAXBContext context = JAXBContext.newInstance(classesToBeBound);
Unmarshaller um = context.createUnmarshaller();
entity = um.unmarshal(file);
} catch (JAXBException ex) {
Logger.getLogger(XmlSerialization.class.getName()).log(Level.SEVERE, null, ex);
}
return entity;
}
public static void write(String filePath, Object entity, Class... classesToBeBound) {
File file = new File(filePath);
try {
JAXBContext context = JAXBContext.newInstance(classesToBeBound);
Marshaller m = context.createMarshaller();
m.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
m.marshal(entity, file);
} catch (JAXBException ex) {
Logger.getLogger(XmlSerialization.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
public Container createContainer() {
Container container = new Container();
for(long i = 1 ; i < 5; ++i) {
Element elem = new Element();
elem.setId(i);
container.getElemLst().add(elem);
Component comp = new Component();
comp.setId(i);
comp.setElem(elem);
container.getLst().add(comp);
}
return container;
}
public void write(String filePath, Container container) {
XmlSerialization.write(filePath, container, Container.class, Component.class, Element.class);
}
public Container read(String filePath) {
Container container = null;
try {
container = (Container)XmlSerialization.read(filePath, Container.class, Component.class, Element.class);
} catch (FileNotFoundException ex) {
Logger.getLogger(MultiID.class.getName()).log(Level.SEVERE, null, ex);
}
return container;
}
public static void main(String[] args) {
MultiID test = new MultiID();
String filePath = "c:\\tmp.xml";
Container c1 = test.createContainer();
test.write(filePath, c1);
Container c2 = test.read(filePath);
filePath = "c:\\tmp2.xml";
test.write(filePath, c2);
}
}
The outputs:
[tmp.xml]
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<container>
<elemList>
<elem id="1"/>
<elem id="2"/>
<elem id="3"/>
<elem id="4"/>
</elemList>
<componentList>
<component id="1" elem="1"/>
<component id="2" elem="2"/>
<component id="3" elem="3"/>
<component id="4" elem="4"/>
</componentList>
</container>
[tmp2.xml]
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<container>
<elemList>
<elem id="1"/>
<elem id="2"/>
<elem id="3"/>
<elem id="4"/>
</elemList>
<componentList>
<component id="1"/>
<component id="2"/>
<component id="3"/>
<component id="4"/>
</componentList>
</container>
Every “Component” in tmp2.xml has no element reference.
That’s the problem.
If we change component id starting from 100, for example, it will work as expect.
How to resolve this issue?
Thanks a lot.
Your output is due to a bug in the implementation of JAXB (JSR-222) that you are using. Running your sample code with the JAXB impl included in JDK 1.7.0 for the Mac and EclipseLink JAXB (MOXy) I get the expected result for tmp2.xml.
tmp2.xml