Django 实现文件上传下载API

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开发环境

Win 10

Python 3.5.4

Django-2.0.13.tar.gz

官方下载地址：

https://www.djangoproject.com/download/2.0.13/tarball/

vue 2.5.2

djangorestframework-3.9.4

下载地址：

https://github.com/encode/django-rest-framework

附件表设计

fromdjango.dbimport models

# Create your models here.

# 附件表

classAttachment(models.Model):

    id = models.AutoField(primary_key=True, verbose_name='自增id')

    name = models.CharField(max_length=200, verbose_name='附件名称')

file_path = models.CharField(max_length=200, verbose_name='附件相对路径')

create_time =  models.DateTimeField(verbose_name='上传时间')

classMeta:

db_table = 'tb_attachment'

verbose_name = '附件表'

verbose_name_plural = verbose_name

项目urls.py配置

修改项目根目录下的urls.py，添加以下带背景色部分的代码内容

#!/usr/bin/env python

# -*- coding:utf-8 -*-

__author__ = '授客'

fromdjango.contribimport admin

fromdjango.urlsimport path

fromdjango.conf.urlsimport include

urlpatterns = [

path('admin/', admin.site.urls),

path('', include('mywebsite.urls'))

]

项目settings.py配置

在文件末尾添加以下配置，用于存放附件

MEDIA_URL = '/media/'

MEDIA_ROOT = os.path.join(BASE_DIR, 'media').replace('\\', '/')

应用view视图编写

例中直接在views.py视图编写视图，代码如下

#!/usr/bin/env python

# -*- coding:utf-8 -*-

__author__ = '授客'

from rest_framework.views import APIView

from rest_framework.response import Response

from rest_framework import status

from .models import Attachment

from django.http import FileResponse

from django.utils import timezone

from django.conf import settings

import os

import uuid

importlogging

logger = logging.getLogger('mylogger')

# 批量创建目录

defmkdirs_in_batch(path):

try:

        path = os.path.normpath(path)  # 去掉路径最右侧的 \\ 、/

path = path.replace('\\', '/') # 将所有的\\转为/，避免出现转义字符串

head, tail = os.path.split(path)

if not os.path.isdir(path) and os.path.isfile(path):  # 如果path指向的是文件，则分解文件所在目录

head, tail = os.path.split(head)

if tail == '': # head为根目录，形如 / 、D:

return True

new_dir_path = ''  # 存放反转后的目录路径

root = ''  # 存放根目录

whiletail:

new_dir_path = new_dir_path + tail + '/'

head, tail = os.path.split(head)

root = head

else:

new_dir_path = root + new_dir_path

# 批量创建目录

new_dir_path = os.path.normpath(new_dir_path)

head, tail = os.path.split(new_dir_path)

temp = ''

whiletail:

temp = temp + '/' + tail

dir_path = root + temp

if not os.path.isdir(dir_path):

os.mkdir(dir_path)

head, tail = os.path.split(head)

return True

exceptException as e:

logger.error('批量创建目录出错：%s' % e)

return False

classAttachmentAPIView(APIView):

# 上传附件

defpost(self, request, format=None):

result = {}

try:

files = request.FILES

file = files.get('file')

if not file:

                result['msg'] =  '上传失败，未获取到文件'

result['success'] =  False

returnResponse(result, status.HTTP_400_BAD_REQUEST)

   # data = request.POST #获取前端发送的，file之外的其它参数

# extra = data.get('extr')

file_name = file.name

attachment_name = file_name

creater = request.user.username

create_time = timezone.now()

time_str = create_time.strftime('%Y%m%d')

name, suffix = os.path.splitext(file_name)

file_name = str(uuid.uuid1()).replace('-', '') + time_str + suffix

file_relative_path = '/myapp/attachments/'+ time_str

file_absolute_path = settings.MEDIA_ROOT + file_relative_path

if not os.path.exists(file_absolute_path):# 路径不存在

if not utils.mkdirs_in_batch(file_absolute_path):

                    result['msg'] =  '批量创建路径(%s)对应的目录失败' % file_absolute_path

result['success'] =  False

returnResponse(result, status.HTTP_500_INTERNAL_SERVER_ERROR)

file_relative_path += '/' + file_name

data['file_path'] = file_relative_path

file_absolute_path = file_absolute_path + '/' + file_name

file_handler = open(file_absolute_path, 'wb')    # 打开特定的文件进行二进制的写操作

try:

for chunk in file.chunks():      # 分块写入文件

file_handler.write(chunk)

finally:

file_handler.close()

# 记录到数据库

try:

obj = Attachment(file_path=file_path, name=attachment_name, create_time=create_time, creater=creater)

obj.save()

exceptException as e:

                result['msg'] =  '上传失败：%s' % e

result['success'] =  False

returnResponse(result, status.HTTP_400_BAD_REQUEST)

result['msg'] =  '上传成功'

result['success'] =  True

result['data'] =  result_data

returnResponse(result, status.HTTP_200_OK)

exceptException as e:

result['msg'] =  '%s' % e

result['success'] =  False

returnResponse(result, status.HTTP_500_INTERNAL_SERVER_ERROR)

注意：这里采用UploadedFile.chunks()分块写入，而不是直接使用UploadedFile.read()一次性读取整个文件，是因为如果文件比较大，一次性读取过多内容，会占用系统过多的内存，进而让系统变得更低效。默认的chunks分块默认值为2.5M

file = files.get('file')# 注意：这里的字典key'file'要和前端提交form表单请求时，文件对象对应的表单key保持一致，前端代码如下

letform = newFormData();

form.append("file", file);

# 删除附件

def delete(self, request, format=None):

result = {}

try:

data = request.data

attachment_id = data.get('attachment_id')

obj = Attachment.objects.filter(id=attachment_id).first()

ifobj:

file_absoulte_path = settings.MEDIA_ROOT + '/'+ obj.file_path

ifos.path.exists(file_absoulte_path) and os.path.isfile(file_absoulte_path):

os.remove(file_absoulte_path)

obj.delete()

result['msg'] =  '删除成功'

result['success'] =  True

returnResponse(result, status.HTTP_200_OK)

exceptException as e:

result['msg'] =  '%s' % e

result['success'] =  False

returnResponse(result, status.HTTP_500_INTERNAL_SERVER_ERROR)

# 下载附件

defget(self, request, format=None):

result = {}

try:

data = request.GET

attachment_id = data.get('attachmentId')

obj = Attachment.objects.filter(id=attachment_id).first()

ifobj:

file_absoulte_path = settings.MEDIA_ROOT+  obj.file_path

ifos.path.exists(file_absoulte_path) and os.path.isfile(file_absoulte_path):

file = open(file_absoulte_path, 'rb')

file_response = FileResponse(file)

file_response['Content-Type']='application/octet-stream'

file_response["Access-Control-Expose-Headers"] = 'Content-Disposition' # 设置可以作为响应的一部分暴露给外部的请求头，如果缺少这行代码，会导致前端请求响应中看不到该请求头

file_response['Content-Disposition']='attachment;filename={}'.format(urlquote(obj.name)) # 这里使用urlquote函数主要为针对文件名为中文时，对文件名进行编码，编码后，前端获取的文件名称形如“%E5%AF%BC%E5%87%BA%E6%B5%8B%E8%AF%95%E7%94%A8%E4%BE%8B”

returnfile_response

else:

result['msg'] =  '请求失败,资源不存在'

result['success'] =  False

else:

result['msg'] =  '请求失败,资源不存在'

result['success'] =  False

returnResponse(result, status.HTTP_200_OK)

exceptException as e:

result['msg'] =  '%s' % e

result['success'] =  False

returnResponse(result, status.HTTP_500_INTERNAL_SERVER_ERROR)

说明：

file_response = FileResponse(file)，可以在引入StreamingHttpResponse之后（from django.http import StreamingHttpResponse）,替换为

file_response = StreamingHttpResponse(file)

前端获取响应头中文件名方法如下：

let disposition = res.headers["content-disposition"];

let filename = decodeURI(disposition.replace("attachment;filename=", "") );

# do something,比如下载：

link.setAttribute("download", filename);

应用urls.py配置

新建urls.py，文件内容如下：

#!/usr/bin/env python

# -*- coding:utf-8 -*-

__author__ = '授客'

from django.urlsimport re_path

from.views import AttachmentAPIView

urlpatterns = [

...

re_path('^api/v1/testcase/\d+/attachment$', testcase_attachment_views.TestcaseAttachmentAPIView.as_view()), # 给测试用例添加附件

re_path('^api/v1/testcase/\d+/attachment/\d+$', testcase_attachment_views.TestcaseAttachmentAPIView.as_view()), # 删除、下载测试用例关联的附件

]

前端实现

略

参考链接

https://docs.djangoproject.com/zh-hans/2.1/topics/http/file-uploads/

https://docs.djangoproject.com/zh-hans/2.0/ref/files/uploads/