Exception in Hessian Serialization

I have a strange problem with Hessian.
I am transferring files - the object being transferred through Hessian
contains a File field.
I have one object for which this works perfectly. I have another object
which fails inelegantly. Both objects use the same code to get the file
into the system (JFileChooser etc etc). Even using the same file when
testing , the result is the same. Object 1 works, Object 2 fails.

I am using Windows XP, Eclipse 3 and JDK1.4.2_05

I found a similar issue on the Sun Java Forums, which states that this
is probably a bug in Hessian:
http://forum.java.sun.com/thread.jsp?forum=62&thread=520000&tstart=135&trange=15

Any help would be appreciated.

Stack Trace:

java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown
Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at
com.caucho.hessian.io.JavaDeserializer.instantiate(JavaDeserializer.java:168)
    at
com.caucho.hessian.io.JavaDeserializer.readMap(JavaDeserializer.java:103)
    at com.caucho.hessian.io.HessianInput.readObject(HessianInput.java:995)
    at
com.caucho.hessian.io.JavaDeserializer.readMap(JavaDeserializer.java:128)
    at
com.caucho.hessian.io.JavaDeserializer.readMap(JavaDeserializer.java:105)
    at
com.caucho.hessian.io.SerializerFactory.readMap(SerializerFactory.java:222)
    at com.caucho.hessian.io.HessianInput.readObject(HessianInput.java:1120)
    at
com.caucho.hessian.io.CollectionDeserializer.readList(CollectionDeserializer.java:106)
    at com.caucho.hessian.io.HessianInput.readObject(HessianInput.java:1015)
    at
com.caucho.hessian.io.JavaDeserializer.readMap(JavaDeserializer.java:128)
    at
com.caucho.hessian.io.JavaDeserializer.readMap(JavaDeserializer.java:105)
    at
com.caucho.hessian.io.SerializerFactory.readMap(SerializerFactory.java:222)
    at com.caucho.hessian.io.HessianInput.readObject(HessianInput.java:1120)
    at
com.caucho.hessian.io.CollectionDeserializer.readList(CollectionDeserializer.java:106)
    at com.caucho.hessian.io.HessianInput.readObject(HessianInput.java:1015)
    at
com.caucho.hessian.io.JavaDeserializer.readMap(JavaDeserializer.java:128)
    at
com.caucho.hessian.io.JavaDeserializer.readMap(JavaDeserializer.java:105)
    at com.caucho.hessian.io.HessianInput.readObject(HessianInput.java:999)
    at
com.caucho.hessian.io.JavaDeserializer.readMap(JavaDeserializer.java:128)
    at
com.caucho.hessian.io.JavaDeserializer.readMap(JavaDeserializer.java:105)
    at com.caucho.hessian.io.HessianInput.readObject(HessianInput.java:999)
    at
com.caucho.hessian.server.HessianSkeleton.invoke(HessianSkeleton.java:134)
    at
com.caucho.hessian.server.HessianServlet.service(HessianServlet.java:293)
    at
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:237)
    at
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
    at
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:214)
    at
org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
    at
org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
    at
org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:198)
    at
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:152)
    at
org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
    at
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:462)
    at
org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:102)
    at
org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
    at
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:137)
    at
org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
    at
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:118)
    at
org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:102)
    at
org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
    at
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
    at
org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
    at
org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
    at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:929)
    at
org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:160)
    at
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:799)
    at
org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:705)
    at
org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:577)
    at
org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:683)
    at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NullPointerException
    at sun.awt.shell.Win32ShellFolder2.<init>(Unknown Source)
    ... 53 more

-- 
Toby Hede
Software Engineer
Web Alive Technologies Pty Ltd
The OSSI Group Pty Ltd
Level 1, Innovation Building
Digital Harbour, 1010 La Trobe Street
Melbourne VIC 3000
P: +61 3 9934 0888
F: +61 3 9934 0899
E: toby.hede@xxx.biz
W: www.webalive.biz
 
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