Bug 138552 [Smoke][Regression]The web viewer can not work
Description: The web viewer can not work Steps to reproduce: 1. new a report 2. new a label and input something in the label 3. save and preview with the web viewer Actual result: Nothing is displayed.
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/context/ViewerAttributeBean.java
{
			if ( reportDesignDocFile.lastModified( ) > reportDocFile
					.lastModified( )
					|| ParameterAccessor.isOverwrite( request ) )
			{
				reportDocFile.delete( );
			}
		}
	}
	/**
	 * Get report service instance.
	 */
	protected IViewerReportService getReportService( )
	{
		return BirtReportServiceFactory.getReportService( );
	}
	/**
	 * Clear our resources.
	 * 
	 * @exception Throwable
	 * @return
	 */
	protected void __finalize( ) throws Throwable
	{
	}
	protected Object getParamValueObject( HttpServletRequest request,
			IScalarParameterDefn parameterObj ) throws ReportServiceException
	{
		String paramName = parameterObj.getName( );
		String format = parameterObj.getDisplayFormat( );