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
ParameterGroupDefinition paramGroup = new ParameterGroupDefinition(
				engineParam.getName( ), engineParam.getDisplayName( ),
				engineParam.getPromptText( ), null, cascade );
		List contents = convertParametersInGroup( engineParam.getContents( ),
				paramGroup, task );
		paramGroup.setParameters( contents );
		return paramGroup;
	}
	private static ParameterDefinition convertScalarParameter(
			IScalarParameterDefn engineParam, ParameterGroupDefinition group,
			IGetParameterDefinitionTask task )
	{
		Object handle = engineParam.getHandle( );
		ScalarParameterHandle scalarParamHandle = null;
		if ( handle instanceof ScalarParameterHandle )
			scalarParamHandle = (ScalarParameterHandle) handle;
		String name = engineParam.getName( );
		String pattern = scalarParamHandle == null ? "" : scalarParamHandle
				.getPattern( );
		String displayFormat = engineParam.getDisplayFormat( );
		String displayName = engineParam.getDisplayName( );
		String helpText = engineParam.getHelpText( );
		String promptText = engineParam.getPromptText( );
		int dataType = engineParam.getDataType( );
		int controlType = engineParam.getControlType( );
		boolean hidden = engineParam.isHidden( );
		boolean allowNull = engineParam.allowNull( );
		boolean allowBlank = engineParam.allowBlank( );
		boolean mustMatch = scalarParamHandle == null
				? false