jasperreports: can see background image in pdf export but not in docx export

Question

Report generation:

The following code resides in a servlet and generates both a "letter.docx" word document to download and a "pika.pdf" file in C:

I am able to see the background image i defined in pika, but not in "letter".

        InputStream is = request.getServletContext().getResourceAsStream("/resources/reports/" +name);      
        JasperReport jr = JasperCompileManager.compileReport(is);                           
        JasperPrint jp = JasperFillManager.fillReport(jr, params, ds);      
        JRExporter exp = new JRDocxExporter();
        exp.setParameter(JRExporterParameter.JASPER_PRINT, jp);         
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        exp.setParameter(JRExporterParameter.OUTPUT_STREAM, bos);       
        exp.exportReport(); 

        JasperExportManager.exportReportToPdfFile(jp, "C:\\pika.pdf");

        byte[] bytes = bos.toByteArray();       

        response.reset();       
        response.setContentType("application/octet-stream");
        response.setHeader("Content-disposition", "attachment; filename=\"letter.docx\"");              
        response.getOutputStream().write(bytes);
        response.getOutputStream().flush();
        response.getOutputStream().close();     

Answer 1

JRDocxExporter is a grid exporter, it generates a table and then populates each cell of this table with the elements in the jasper template. If an element in the template overlaps another element, the further element does not display, because in a table a cell cannot overlap another cell.