Error java.lang.NoClassDefFoundError: Could not initialize class com.sun.xml.internal.ws.api.streaming.XMLStreamReaderFactory

I am working on Jira SDK 6.1.6 to develop a plugin connecting to MicroSoft Web services, in Eclipse with java (1.6) everything goes fine to connect to the MS Web Services.
Did debug the web service call to see if the request is able to find the com.sun.xml.internal.ws.api.streaming.XMLStreamReaderFactory in Eclipse, and yes was able find from "rt.jar" (in JRE/lib folder, Java default implementation).

When tried to deploy the same plugin (developed) into Jira instance downloaded from the URL (http://www.atlassian.com/software/jira/download) 64 bit windows instance.
(Jira instances 6.1.5, 6.2.3 and 6.2.4 versions, Same error on all the 3 versions).
After deploying the plugin get the Initial error:
javax.xml.stream.FactoryFinder$ConfigurationError: Provider com.ctc.wstx.stax.WstxInputFactory not found
at javax.xml.stream.FactoryFinder.newInstance(Unknown Source)
at javax.xml.stream.FactoryFinder.findJarServiceProvider(Unknown Source)
at javax.xml.stream.FactoryFinder.find(Unknown Source)
at javax.xml.stream.FactoryFinder.find(Unknown Source)
at javax.xml.stream.XMLInputFactory.newInstance(Unknown Source)
at com.sun.xml.internal.ws.policy.sourcemodel.XmlPolicyModelUnmarshaller.createXMLEventReader(Unknown Source)
.
.
.

And after refresh the browser get the error:
java.lang.NoClassDefFoundError: Could not initialize class com.sun.xml.internal.ws.api.streaming.XMLStreamReaderFactory
at com.sun.xml.internal.ws.wsdl.parser.RuntimeWSDLParser.createReader(Unknown Source)
at com.sun.xml.internal.ws.wsdl.parser.RuntimeWSDLParser.resolveWSDL(Unknown Source)
at com.sun.xml.internal.ws.wsdl.parser.RuntimeWSDLParser.parse(Unknown Source)
at com.sun.xml.internal.ws.wsdl.parser.RuntimeWSDLParser.parse(Unknown Source)
at com.sun.xml.internal.ws.client.WSServiceDelegate.parseWSDL(Unknown Source)
at com.sun.xml.internal.ws.client.WSServiceDelegate.<init>(Unknown Source)
.
.
.

Attached are the files with complete stack trace.

Extracted the rt.jar from Jira installation path (<installation_folder>\Atlassian\JIRA\jre\lib\rt.jar) Even though the JRE/lib contains the com.sun.xml.internal.ws.api.streaming.XMLStreamReaderFactory class, but not available at run time.

Had a look on
https://jira.atlassian.com/browse/JRA-26214
https://jira.atlassian.com/browse/CONF-27669
and tried to read the documentation how to use the workaround as in URL (https://bitbucket.org/fakraemer/confluence-smithereens/src/aa131c174b24/src/main/java/com/atlassian/confluence/plugins/smithereens/DefaultXmlFactoryFacade.java?at=refactoring#cl-27) which does not exist!

Help would be greatly appreciated for any workaround or fix to deploy the plugin into Jira instance.

--Thanks
Manjunath