Django

Question

我的静态文件中有一个 pdf，我需要给它添加一些文本并让用户下载它，但是下载部分给我带来了一些问题，这是我的部分代码：

views.py

import io
from werkzeug.wsgi import FileWrapper
from pathlib import Path
from PyPDF2 import PdfFileWriter, PdfFileReader
from reportlab.pdfgen import canvas
from reportlab.lib.pagesizes import letter
from django.http import HttpResponse, FileResponse

def downloadpdf(request):
    pdf_path = (Path.home()/"bot"/"mysite"/"static"/"images"/"tesseragenerica.pdf")

    # 1
    pdf_reader = PdfFileReader(str(pdf_path))
    packet = io.BytesIO()

    # create a new PDF with Reportlab
    can = canvas.Canvas(packet, pagesize=letter)
    testo = "text to add" #in future "text to add" will be the username
    can.drawString(5, 5, testo)
    can.save()

    #move to the beginning of the StringIO buffer
    packet.seek(0)

    new_pdf = PdfFileReader(packet)

    # read your existing PDF
    existing_pdf = PdfFileReader(open("/home/myusername/bot/mysite/static/images/tesseragenerica.pdf", "rb"))

    output = PdfFileWriter()

    # add the "watermark" (which is the new pdf) on the existing page
    page = existing_pdf.getPage(0)
    page.mergePage(new_pdf.getPage(0))
    output.addPage(page)

    # finally, write "output" to a real file
    outputStream = open("destination3.pdf", "wb")
    output.write(outputStream)
    outputStream.close()
    return FileResponse(FileWrapper(packet), as_attachment=True, filename='hello.pdf')

将文本添加到 pdf 的代码是正确的，因为在本地它可以工作，所以我认为问题是我将其作为 FileResponse 的第一个参数，如果我将 FileWrapper(packet) 作为示例而不是让我下载我在浏览器上看到的文件：

%PDF-1.3 %���� ReportLab Generated PDF document http://www.reportlab.com 1 0 obj << /F1 2 0 R >> endobj 2 0 obj << /BaseFont /Helvetica /Encoding /WinAnsiEncoding /Name /F1 /Subtype /Type1 /Type /Font >> endobj 3 0 obj << /Contents 7 0 R /MediaBox [ 0 0 612 792 ] /Parent 6 0 R /Resources << /Font 1 0 R /ProcSet [ /PDF /Text /ImageB /ImageC /ImageI ] >> /Rotate 0 /Trans << >> /Type /Page >> endobj 4 0 obj << /PageMode /UseNone /Pages 6 0 R /Type /Catalog >> endobj 5 0 obj << /Author (anonymous) /CreationDate (D:20210718122806+00'00') /Creator (ReportLab PDF Library - www.reportlab.com) /Keywords () /ModDate (D:20210718122806+00'00') /Producer (ReportLab PDF Library - www.reportlab.com) /Subject (unspecified) /Title (untitled) /Trapped /False >> endobj 6 0 obj << /Count 1 /Kids [ 3 0 R ] /Type /Pages >> endobj 7 0 obj << /Filter [ /ASCII85Decode /FlateDecode ] /Length 97 >> stream GapQh0E=F,0U\H3T\pNYT^QKk?tc>IP,;W#U1^23ihPEM_?CW4KISh__N8"+NKVeK&quKrKuB2i9neZ[Kb,ht63StAffBaV~>endstream endobj xref 0 8 0000000000 65535 f 0000000073 00000 n 0000000104 00000 n 0000000211 00000 n 0000000404 00000 n 0000000472 00000 n 0000000768 00000 n 0000000827 00000 n trailer << /ID [<75dce57879667ca53ee6edf7352f4f98><75dce57879667ca53ee6edf7352f4f98>] % ReportLab generated PDF document -- digest (http://www.reportlab.com) /Info 5 0 R /Root 4 0 R /Size 8 >> startxref 1013 %%EOF

我认为这是一个 pdf 文件，但不明白为什么浏览器显示它而不是下载它。我认为（并希望）我接近解决方案，但我不知道我做错了什么。我该怎么做才能使 pdf 可下载？谢谢

Answer 1

如果文件响应是浏览器可识别的格式，则浏览器会显示文件响应。正如浏览器所识别的那样，浏览器会显示预览。如果想强制用户下载，有两种方法。

首先，如果您要 link 下载 url，请将下载属性添加到来自 html 的 link。 <a href="download/example.pdf" download>download me pls</a>

如果您想从 python 开始，或者必须在 python 中完成，那么您可以 return HttpResponse 对象，但带有强制下载的 content_type 。示例：

def download(request, path):
    file_path = os.path.join(settings.MEDIA_ROOT, path)
    if os.path.exists(file_path):
        with open(file_path, 'rb') as fh:
            response = HttpResponse(fh.read(), content_type="application/force-download")
            response['Content-Disposition'] = 'inline; filename=' + os.path.basename(file_path)
            return response
    raise Http404

资源：Having Django serve downloadable files

Answer 2

您可以用更少的代码来完成。如果你的文件路径是静态的而不是动态的，你可以用 file_path = "/static/your_file_path/"

来改变

def download_file_from_server(request):
    file_path = request.GET["file_path"]
    file = open(os.path.join(settings.BASE_DIR, file_path), 'rb')
    response = FileResponse(file)
    return response

Django - 无法下载文件（改为显示为文本）

Django - can't download file (showed as text instead)

python

pdf

download

bytesio