Converter for Throwable that retains stack trace

Looking at the source to Throwable, it appears that the JVM does some special 'magic' to set the stack trace.

— from Brian Oxley —

> I had trouble getting a simple unit test to pass for serializing exceptions in XStream 1.0. The stack trace didn't make it.
>
> I checked the issue tracker and did not see anything about this, and my Google searches of lists.codehaus.org and searching the full archive weren't fruitful.
>
> Looking into the Throwable from JDK 1.4.2_02, I see (code at bottom) which makes me expect it to "just work". However the XML for serializing a Throwable is:
>
> <java.lang.Throwable>
> <cause>
> <cause reference=".."/>
> <detailMessage>some message</detailMessage>
> </cause>
> <detailMessage>some other message</detailMessage>
> </java.lang.Throwable>
>
> For whatever reason, the JDK uses a cause of "this" when a Throwable has no cause, and XStream is serializing the field's reference rather than what getCause() returns (which is "null" when cause is "this").
>
> What's the best way for me to maintainably code serialization of exceptions with XStream?
>
>
> Cheers,
> --binkley
>
>
> Code:
>
> /**
> * Native code saves some indication of the stack backtrace in this slot.
> */
> private transient Object backtrace;
>
> /**
> * Specific details about the Throwable. For example, for
> * <tt>FileNotFoundException</tt>, this contains the name of
> * the file that could not be found.
> *
> * @serial
> */
> private String detailMessage;
>
> /**
> * The throwable that caused this throwable to get thrown, or null if this
> * throwable was not caused by another throwable, or if the causative
> * throwable is unknown. If this field is equal to this throwable itself,
> * it indicates that the cause of this throwable has not yet been
> * initialized.
> *
> * @serial
> * @since 1.4
> */
> private Throwable cause = this;
>
> /**
> * The stack trace, as returned by

.
> *
> * @serial
> * @since 1.4
> */
> private StackTraceElement[] stackTrace;
> /*
> * This field is lazily initialized on first use or serialization and
> * nulled out when fillInStackTrace is called.
> */