Bug 141951 Export data throw NPE when target document doesn't exist
Description: Export data doesn't work when deploy birt in WebSphere6 Steps to reproduce: 1. Deploy birt in WebSphere6 2. Preview report and click Export Data Result: java.lang.NullPointerException Stack Trace: org.apache.axis.AxisFault.makeFault(AxisFault.java:101) org.eclipse.birt.report.soapengine.processor.AbstractBaseComponentProcessor.process(Unknown Source) org.eclipse.birt.report.soapengine.endpoint.BirtSoapBindingImpl.getUpdatedObjects(Unknown Source) sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) sun.reflect.NativeMethodAccessorImpl
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/service/BirtViewerReportService.java
}
	public Collection getParameterDefinitions(
			IViewerReportDesignHandle design, InputOptions runOptions,
			boolean includeGroups ) throws ReportServiceException
	{
		IGetParameterDefinitionTask task = getParameterDefinitionTask( design );
		return convertEngineParameters( task.getParameterDefns( true ), task,
				includeGroups );
	}
	public Map getParameterValues( String docName, InputOptions options )
			throws ReportServiceException
	{
		IReportDocument doc = ReportEngineService.getInstance( )
				.openReportDocument( getReportDesignName( options ), docName );
		Map paramValues = doc.getParameterValues( );
		doc.close( );
		return paramValues;
	}
	public Collection getSelectionListForCascadingGroup(
			IViewerReportDesignHandle design, String groupName,
			Object[] groupKeys, InputOptions options )
			throws ReportServiceException
	{
		IGetParameterDefinitionTask task = getParameterDefinitionTask( design );
		task.evaluateQuery( groupName );
		Collection selectionList = task.getSelectionListForCascadingGroup(
				groupName, groupKeys );
		return convertEngineParameterSelectionChoice( selectionList );
	}
	public Collection getParameterSelectionList(