Generate ZIP with PDFs inside

Question

I need to return a HttpServletResponse to download a ZIP file with PDFs inside using iText. This is my code:

           String fileName = "Acreditaciones.zip";

           ByteArrayOutputStream baos = new ByteArrayOutputStream();
           ZipOutputStream zos = new ZipOutputStream(baos);

           for(int i = 0; i < numAcre; i++){
               zos.putNextEntry(new ZipEntry("Acreditaciones" +  String.valueOf(i+1) + ".pdf"));

               Document document = new Document();
               PdfWriter.getInstance(document, baos);

               //Abrimos el documento para insertarle contenido
               document.open();

               //TODO: Coger la URL de los parametros de la BD y cifrar el id del perceptor o la columna que lo identifique
               //Creamos imagen con codigo QR
               BarcodeQRCode barcodeQRCode2 = new BarcodeQRCode(URL + UtilsSeguridad.cifrar("80004244D"), 1000, 1000, null);
               Image codeQrImage2 = barcodeQRCode2.getImage();
               codeQrImage2.setAlignment(Image.RIGHT);
               codeQrImage2.scaleAbsolute(70, 70);
               document.add(codeQrImage2);

               document.close();
               zos.closeEntry();
           }

           zos.finish();
           zos.close();

           response.setHeader("Content-Disposition", "attachment; filename=\""+ fileName + "\";");
           // Indicamos que es un PDF
           response.setContentType("application/zip");
           // El tamaño del contenido es igual al del ByteArrayOutputStream
           response.setContentLength(baos.size());
           // Inyectamos el ByteArrayOutputStream al ServletOutputStream
           ServletOutputStream os = response.getOutputStream();
           baos.writeTo(os);
           os.flush();
           os.close();
           FacesContext.getCurrentInstance().responseComplete();

When I download the ZIP file, this come with all the PDFs corrupts and without size... I don't know what I'm doing wrong, but seems that the documents are not being instantiated.

Answer 1

Replace the following line:

PdfWriter.getInstance(document, baos);

with these two lines:

PdfWriter writer = PdfWriter.getInstance(document, zos);
writer.setCloseStream(false);

Don't forget to tell the writer instance not to close the underlying stream, otherwise closing the document instance will also close the ZipOutputStream , and you won't be able to add new entries.