Java security Exception

[fabio]

Hi, I'm writing a program for PPC and I use IBM's Websphere Device
Developper PPRO1.0 java VM. This vm is much smaller and simple than standard
vm as it has to run on small devices as handhelds. And lot of java standard
base classes are not present. I needed package java.nio.* to run stax (a xml
utility) so I copied-pasted from rt.jar the package java.nio.* and imported
it in the classpath of my project. But when I ran my class I got this error:

Exception in thread "main" java.lang.SecurityException:
java.nio.charset.Charset - protected system package 'java.nio.charset'
at java.lang.ClassLoader.checkClassName(ClassLoader.j ava:167)
at java.lang.ClassLoader.defineClass(ClassLoader.java :208)
at java.security.SecureClassLoader.defineClass(Secure ClassLoader.java:109)
at java.net.URLClassLoader.findClassImpl(URLClassLoad er.java:1026)
at java.net.URLClassLoader$4.run(URLClassLoader.java: 557)
at java.security.AccessController.doPrivileged(Access Controller.java:167)
at java.net.URLClassLoader.findClass(URLClassLoader.j ava:555)
at
com.ibm.oti.vm.URLSystemClassLoader.findClass(URLS ystemClassLoader.java:32)
at java.lang.ClassLoader.loadClass(ClassLoader.java:6 02)
at
com.ibm.oti.vm.URLSystemClassLoader.loadClass(URLS ystemClassLoader.java:65)
at java.lang.ClassLoader.loadClass(ClassLoader.java:5 61)
at com.bea.xml.stream.XMLWriterBase.setWriter(XMLWrit erBase.java:54)
at com.bea.xml.stream.XMLWriterBase.<init>(XMLWriterB ase.java:46)
at
com.bea.xml.stream.XMLOutputFactoryBase.createXMLS treamWriter(XMLOutputFactoryBase.java:28)
at
com.bea.xml.stream.XMLOutputFactoryBase.createXMLS treamWriter(XMLOutputFactoryBase.java:37)
at unused.LoadXML.main(LoadXML.java:40)

How can I solve it? Is it concerned with java.policy and java.security
files?
Thanks
Faabio