使用spring boot和itext将java HTML呈现为可下载的PDF

Question

我正在做一个项目，我需要使用一个HTML模板来填充一些参数，将其呈现为PDF格式，最后将其作为下载返回到响应中

此时，正如您将在我的服务上看到的，我可以生成要呈现的最终HTML。它完全起作用了

//bla bla Service code
@Override
    public String buildHtmlFromTemplate(String voucherUUid, Date created, String employerDenomination, String employerEmail) {
        ClassLoaderTemplateResolver templateResolver = new ClassLoaderTemplateResolver();
        templateResolver.setSuffix(".html");
        templateResolver.setTemplateMode("HTML");
        templateResolver.setCacheable(false);

        TemplateEngine templateEngine = new TemplateEngine();
        templateEngine.setTemplateResolver(templateResolver);

        Context context = new Context();
        context.setVariable("voucherUuid", voucherUUid);
        context.setVariable("voucherCreated", created);
        context.setVariable("employerDenomination", employerDenomination);
        context.setVariable("employerEmail", employerEmail);

        // Get the plain HTML with the resolved ${name} variable!
        return templateEngine.process("pdf_templates/voucher", context);

    }
//bla bla Service code

阅读文档，显然在Stacky的帮助下，可以创建以下两种方法：

第一个渲染html并在服务器内生成一个文件。我还是无法下载

//bla bla service code
    @Override
    public void generateVoucher(String html) throws IOException, DocumentException {
        OutputStream outputStream = new FileOutputStream("message.pdf");
        ITextRenderer renderer = new ITextRenderer();
        renderer.setDocumentFromString(html);
        renderer.layout();
        renderer.createPDF(outputStream);
        outputStream.close();

    }
//bla bla Service code

使用第二个，我可以下载PDF文件，但显然，它没有呈现。因此，我收到了PDF中的计划HTML

//bla bla Service code
    @Override
    public ByteArrayOutputStream generateVoucherDocument(String html) throws IOException, DocumentException {
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        Document document = new Document(PageSize.A4);
        PdfWriter.getInstance(document, bos);
        document.open();
        document.addAuthor("Me");
        document.add(new Paragraph(html));
        document.close();

        return bos;

    }
//bla bla Service code

Itext渲染器不支持BAO

这是我的控制器代码：

@GetMapping("/download")
    public void download(HttpServletResponse response) throws IOException, DocumentException {
        //TODO implementar logica para obtener los datos del voucher
        String htmlInvoice = voucherService.buildHtmlFromTemplate(UUID.randomUUID().toString(), new Date(), "Empleador", "encargado@empleador.com");


        ByteArrayOutputStream bos = voucherService.generateVoucherDocument(htmlInvoice);
        byte[] pdfReport = bos.toByteArray();

        String mimeType =  "application/pdf";
        response.setContentType(mimeType);
        response.setHeader("Content-Disposition", String.format("attachment; filename=\"%s\"", "voucherLiquidacion.pdf"));

        response.setContentLength(pdfReport.length);

        ByteArrayInputStream inStream = new ByteArrayInputStream( pdfReport);

        FileCopyUtils.copy(inStream, response.getOutputStream());
    }

我真的很困惑如何在PDF中呈现html并将其放置在下载位置。 知道吗