爱站程序员基地Django实现文件上传下载API
by:授客 QQ：1033553122 欢迎加入全国软件测试交流QQ群7156436
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
from django.db import models# Create your models here.# 上传文件表class Attachment(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\'from django.contrib import adminfrom django.urls import pathfrom django.conf.urls import includeurlpatterns = [path(\'admin/\', admin.site.urls),path(\'\', include(\'mywebsite.urls\')) #添加API路由配置（这里根据项目实际情况配置）]
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 APIViewfrom rest_framework.response import Responsefrom rest_framework import statusfrom .models import Attachmentfrom django.http import FileResponsefrom django.utils import timezonefrom django.conf import settingsimport osimport uuidimport logginglogger = logging.getLogger(\'mylogger\')# 批量创建目录def mkdirs_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 == \'\': # hea15a8d为根目录，形如 / 、D:return Truenew_dir_path = \'\' # 存放反转后的目录路径root = \'\' # 存放根目录while tail:new_dir_path = new_dir_path + tail + \'/\'head, tail = os.path.split(head)root = headelse: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 = \'\'while tail:temp = temp + \'/\' + taildir_path = root + tempif not os.path.isdir(dir_path):os.mkdir(dir_path)head, tail = os.path.split(head)return Trueexcept Exception as e:logger.error(\'批量创建目录出错：%s\' % e)return Falseclass AttachmentAPIView(APIView):# 上传附件def post(self, request, format=None):result = {}try:files = request.FILESfile = files.get(\'file\')if not file:result[\'msg\'] = \'上传失败，未获取到文件\'result[\'success\'] = Falsereturn Response(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(\'extra\')file_name = file.nameattachment_name = file_namecreater = request.user.usernamecreate_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 + suffixfile_relative_path = \'/myapp/attachments/\'+ time_strfile_absolute_path = settings.MEDIA_ROOT + file_relative_pathif 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_pathresult[\'success\'] = Falsereturn Response(result, status.HTTP_500_INTERNAL_SERVER_ERROR)file_relative_path += \'/\' + file_namedata[\'file_path\'] = file_relative_pathfile_absolute_path = file_absolute_path + \'/\' + file_namefile_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()except Exception as e:result[\'msg\'] = \'上传失败：%s\' % eresult[\'success\'] = Falsereturn Response(result, status.HTTP_400_BAD_REQUEST)result[\'msg\'] = \'上传成功\'result[\'success\'] = Trueresult[\'data\'] = result_datareturn Response(result, status.HTTP_200_OK)except Exception as e:result[\'msg\'] = \'%s\' % eresult[\'success\'] = Falsereturn Response(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.dataattachment_id = data.get(\'attachment_id\')obj = Attachment.objects.filter(id=attachment_id).first()if obj:file_absoulte_path = settings.MEDIA_ROOT + \'/\'+ obj.file_pathif os.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\'] = Truereturn Response(result, status.HTTP_200_OK)except Exception as e:result[\'msg\'] = \'%s\' % eresult[\'success\'] = Falsereturn Response(result, status.HTTP_500_INTERNAL_SERVER_ERROR)
# 下载附件def get(self, request, format=None):result = {}2088try:data = request.GETattachment_id = data.get(\'attachmentId\')obj = Attachment.objects.filter(id=attachment_id).first()if obj:file_absoulte_path = settings.MEDIA_ROOT+ obj.file_pathif os.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”return file_responseelse:result[\'msg\'] = \'请求失败,资源不存在\'result[\'success\'] = Falseelse:result[\'msg\'] = \'请求失败,资源不存在\'result[\'success\'] = Falsereturn Response(result, status.HTTP_200_OK)except Exception as e:result[\'msg\'] = \'%s\' % eresult[\'success\'] = Falsereturn Response(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：
letdisposition= res.headers[\”content-disposition\”];
letfilename=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.urls import re_pathfrom .views import AttachmentAPIViewurlpatterns = [#...略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
参考文档“ElementUI Upload上传(利用http-request自定义上传)&下载&删除附件”
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/
