使用 servlet 和 itext 生成 zip 文件分组多个 pdf

Question

I'm trying to put multiple generated pdf into a zip from servlet using itext7, I've managed to put one pdf in a zip file but not more. 这是代码：

private void printMore(HttpServletRequest req, HttpServletResponse resp) throws SQLException {
        String masterPath = req.getServletContext().getRealPath("/assets/template/templateStatement.pdf");
        try (PdfReader reader = new PdfReader(masterPath);
             ZipOutputStream zipFile = new ZipOutputStream(resp.getOutputStream());
             PdfWriter writer = new PdfWriter(zipFile);
             PdfDocument pdf = new PdfDocument(reader, writer);
             Document doc = new Document(pdf)) {

            List<Student> studentList = getFactoryDAO().getStatementDAO().selectStudentHasBalance();
            for (Student student : studentList){

                // Generate PDF for the student

                PdfPage page = pdf.getPage(1);
                PdfCanvas canvas = new PdfCanvas(page);

                FontProgram fontProgram = FontProgramFactory.createFont();
                PdfFont font = PdfFontFactory.createFont(fontProgram, "utf-8", true);
                canvas.setFontAndSize(font, 10);

                canvas.beginText();

                canvas.setTextMatrix(178, 650); // student code
                canvas.showText(student.getS_Code());

                canvas.setTextMatrix(200, 610); // Date of Statement
                canvas.showText(new SimpleDateFormat("yyyy-MM-dd").format(new Date()));

                canvas.endText();

                float[] pointsWidth = {60f,120f,70f,70f};
                Table table = new Table(pointsWidth);
                table.setMarginTop(280);
                table.setMarginLeft(70);
                table.setFont(font);
                table.setFontSize(10);
                table.setTextAlignment(TextAlignment.CENTER);
                //Header Table
                table.addCell(new Cell().add("Date Inscription"));
                table.addCell(new Cell().add("Name"));
                table.addCell(new Cell().add("Fees"));
                table.addCell(new Cell().add("Observation"));
                //Detail Table
                table.addCell(new Cell().add(student.getTxnDate()));
                table.addCell(new Cell().add(student.getS_FullName));
                table.addCell(new Cell().add(student.getFees));
                table.addCell(new Cell().add(student.getObservation));
                

                doc.add(table);


                ZipEntry zipEntry = new ZipEntry(student.getS_Code() + "_" + student.getS_LName() + ".pdf");
                zipFile.putNextEntry(zipEntry);
                //zipFile.write(); Shall I use it?

            }
        } catch (IOException e) {
            e.printStackTrace();
        }

        resp.setHeader("Content-disposition","attachement; filename=test.zip");
        resp.setContentType("application/zip");
    }

我基于this post和this post ，但不起作用。 我已经检查了更多这样的帖子，但是 itext7 的版本没有提到的 PdfWriter.getInstance 。 我已经尝试了更多的东西，但无法进一步做到 go。

更新：

在 Enterman 建议后，我将其更新如下：

String masterPath = req.getServletContext().getRealPath("/assets/template/templateStatement.pdf");
        try (PdfReader reader = new PdfReader(masterPath);
             ZipOutputStream zipFile = new ZipOutputStream(resp.getOutputStream());
             PdfWriter writer = new PdfWriter(zipFile);
             PdfDocument pdf = new PdfDocument(reader, writer)
             ) {

            List<Student> studentList = getFactoryDAO().getStatementDAO().selectStudentHasBalance();
            for (Student student : studentList){

                try (Document doc = new Document(pdf)){
                       // Generate PDF for the student

                PdfPage page = pdf.getPage(1);
                PdfCanvas canvas = new PdfCanvas(page);

                FontProgram fontProgram = FontProgramFactory.createFont();
                PdfFont font = PdfFontFactory.createFont(fontProgram, "utf-8", true);
                canvas.setFontAndSize(font, 10);

                canvas.beginText();

                canvas.setTextMatrix(178, 650); // student code
                canvas.showText(student.getS_Code());

                canvas.setTextMatrix(200, 610); // Date of Statement
                canvas.showText(new SimpleDateFormat("yyyy-MM-dd").format(new Date()));

                canvas.endText();

                float[] pointsWidth = {60f,120f,70f,70f};
                Table table = new Table(pointsWidth);
                table.setMarginTop(280);
                table.setMarginLeft(70);
                table.setFont(font);
                table.setFontSize(10);
                table.setTextAlignment(TextAlignment.CENTER);
                //Header Table
                table.addCell(new Cell().add("Date Inscription"));
                table.addCell(new Cell().add("Name"));
                table.addCell(new Cell().add("Fees"));
                table.addCell(new Cell().add("Observation"));
                //Detail Table
                table.addCell(new Cell().add(student.getTxnDate()));
                table.addCell(new Cell().add(student.getS_FullName));
                table.addCell(new Cell().add(student.getFees));
                table.addCell(new Cell().add(student.getObservation));
                

                doc.add(table);


                ZipEntry zipEntry = new ZipEntry(student.getS_Code() + "_" + student.getS_LName() + ".pdf");
                zipFile.putNextEntry(zipEntry);
                //zipFile.write(); Shall I use it?
                }

            }
        } catch (IOException e) {
            e.printStackTrace();
        }

        resp.setHeader("Content-disposition","attachement; filename=test.zip");
        resp.setContentType("application/zip");

但仍然没有运气。

欢迎您的帮助。

Answer 1

您应该尝试使用 FileInputStream，如下所示（我自己的代码，在生产中运行良好）

private File createZip(List<File> forZip, LocalDate date) {

    String zipName = Constants.ORDER_FILE_PATH + date.getYear() +"-" + date.getMonth().getValue() + "-" + date.getMonth().getDisplayName(TextStyle.FULL, Locale.FRENCH) + ".zip";

    FileOutputStream fos = null;
    try {
        fos = new FileOutputStream(zipName);
        ZipOutputStream zipOut = new ZipOutputStream(fos);
        for (File srcFile : forZip) {
            FileInputStream fis = new FileInputStream(srcFile);
            ZipEntry zipEntry = new ZipEntry(srcFile.getName());
            zipOut.putNextEntry(zipEntry);

            byte[] bytes = new byte[1024];
            int length;
            while((length = fis.read(bytes)) >= 0) {
                zipOut.write(bytes, 0, length);
            }
            fis.close();
            //srcFile.delete();
        }
        zipOut.close();
        fos.close();
    } catch (IOException e) {
        logger.error("createZip", e);
    }

    return new File(zipName);
}

Answer 2

特别感谢 BenjaminD、Enterman 和所有堆栈社区的支持。

我为那些和我遇到同样问题的人发布了这个答案。 （我被困了4天）。 “使用 itext 7 和 servlet 生成多个 PDF”

正如 Enterman 所说：“需要新的文档实例”。 另外还需要PdfDocument。 并作为 BenjaminD 指令：“先生成文件 PDF，然后将它们放入 zip 中”。

String masterPath = req.getServletContext().getRealPath("/assets/template/templateStatement.pdf");
        try (ZipOutputStream zipOut = new ZipOutputStream(resp.getOutputStream())) {

            Liste<File> listFile = new ArrayList<>();
            List<Student> studentList = getFactoryDAO().getStatementDAO().selectStudentHasBalance();
            for (Student student : studentList){
                
                File file = new File(student.getS_Code()+"_"+new SimpleDateFormat("yyyy-MM-dd").format(new Date())+".pdf");
                try (PdfDocument pdf = new PdfDocument(new PdfReader(masterPath), new PdfWriter(file.getName()))
                     Document doc = new Document(pdf)){
                       // Generate PDF for the student

                PdfPage page = pdf.getPage(1);
                PdfCanvas canvas = new PdfCanvas(page);

                FontProgram fontProgram = FontProgramFactory.createFont();
                PdfFont font = PdfFontFactory.createFont(fontProgram, "utf-8", true);
                canvas.setFontAndSize(font, 10);

                canvas.beginText();

                canvas.setTextMatrix(178, 650); // student code
                canvas.showText(student.getS_Code());

                canvas.setTextMatrix(200, 610); // Date of Statement
                canvas.showText(new SimpleDateFormat("yyyy-MM-dd").format(new Date()));

                canvas.endText();

                float[] pointsWidth = {60f,120f,70f,70f};
                Table table = new Table(pointsWidth);
                table.setMarginTop(280);
                table.setMarginLeft(70);
                table.setFont(font);
                table.setFontSize(10);
                table.setTextAlignment(TextAlignment.CENTER);
                //Header Table
                table.addCell(new Cell().add("Date Inscription"));
                table.addCell(new Cell().add("Name"));
                table.addCell(new Cell().add("Fees"));
                table.addCell(new Cell().add("Observation"));
                //Detail Table
                table.addCell(new Cell().add(student.getTxnDate()));
                table.addCell(new Cell().add(student.getS_FullName));
                table.addCell(new Cell().add(student.getFees));
                table.addCell(new Cell().add(student.getObservation));
                

                doc.add(table);


                listFile.add(file);
                }

            }
            
            File zipFile = createZip(listFile, 
            newSimpleDateFormat("yyyy-MM-dd").format(new Date())); //BenjaminD source in answer

            ZipEntry zipEntry = new ZipEntry(zipFile.getName);
            zipEntry.putNextEntry(zipEntry);
            fileInputStream fis = new FileInputStream(zipFile);
            byte[] bytes = new byte[1024];
            int length;
            while((length = fis.read(bytes)) >= 0) {
                zipOut.write(bytes, 0, length);
            }
            fis.close();

            resp.setHeader("Content-disposition","attachement; filename=" + zipFile);
            resp.setContentType("application/zip");

        } catch (IOException e) {
            e.printStackTrace();
        }     

它将 zip 放入 zip 中（可以直接使用 FileOutpuStream 以不再将其放入 zip 中）。

再次感谢你。