Details
Bug
Closed
Critical
Description
Code below:
import com.thoughtworks.xstream.*;
class MultRef
{
public Object s1 = new Object();
public Object s2 = s1;
}
public class Test2
{
public static void main(String[] args)
{ MultRef multRef1 = new MultRef(); if (multRef1.s1 == multRef1.s2) System.out.println("multRef1: References"); else System.out.println("multRef1: NOT References"); XStream xstream = new XStream(); String xml = xstream.toXML(multRef1); System.out.println(xml); MultRef multRef2 = (MultRef)xstream.fromXML(xml); if (multRef2.s1 == multRef2.s2) System.out.println("multRef2: References"); else System.out.println("multRef2: NOT References"); }}
Currently produces:
multRef1: References
<MultRef>
<s1/>
<s2 reference="../s1"/>
</MultRef>
multRef2: NOT References // WRONG!
Reported by Jim Gentilesco.
Activity
I was thinking that in the reference-by-id strategy, we could improve memory usage when unmarshalling by putting fewer id's on the elements when marshalling. But this would require an additional pass when marshalling to determine which id's are necessary.
(Alternately, we could do two passes when unmarshalling, which would work for both strategies.)
Also, the convertAnother(Object parent, Class type) methods could use some refactoring to remove the duplication in ReferenceByIdUnmarshaller and ReferenceByXPathUnmarshaller.
Brian Slesinsky
added a comment - I was thinking that in the reference-by-id strategy, we could improve memory usage when unmarshalling by putting fewer id's on the elements when marshalling. But this would require an additional pass when marshalling to determine which id's are necessary.
(Alternately, we could do two passes when unmarshalling, which would work for both strategies.)
Also, the convertAnother(Object parent, Class type) methods could use some refactoring to remove the duplication in ReferenceByIdUnmarshaller and ReferenceByXPathUnmarshaller. Thanks. I've incorporated your patch with a few modifications.
Joe Walnes
added a comment - Thanks. I've incorporated your patch with a few modifications. 
This patch should fix the problem. The idea is that we need to put a reference to every object into the map since we don't know which ones will have references to them later on in the file.