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
from django.db import models
# Create your models here.
# 附件表
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')
class Meta:
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 admin
from django.urls import path
from django.conf.urls import 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
import logging
logger = 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 == '': # 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
while tail:
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 = ''
while tail:
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
except Exception as e:
logger.error('批量创建目录出错：%s' % e)
return False
class AttachmentAPIView(APIView):
# 上传附件
def post(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
return Response(result, status.HTTP_400_BAD_REQUEST)
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
return Response(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()
except Exception as e:
result['msg'] = '上传失败：%s' % e
result['success'] = False
return Response(result, status.HTTP_400_BAD_REQUEST)
result['msg'] = '上传成功'
result['success'] = True
result['data'] = result_data
return Response(result, status.HTTP_200_OK)
except Exception as e:
result['msg'] = '%s' % e
result['success'] = False
return 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
let form = 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()
if obj:
file_absoulte_path = settings.MEDIA_ROOT + '/'+ obj.file_path
if 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'] = True
return Response(result, status.HTTP_200_OK)
except Exception as e:
result['msg'] = '%s' % e
result['success'] = False
return Response(result, status.HTTP_500_INTERNAL_SERVER_ERROR)
# 下载附件
def get(self, request, format=None):
result = {}
try:
data = request.GET
attachment_id = data.get('attachmentId')
obj = Attachment.objects.filter(id=attachment_id).first()
if obj:
file_absoulte_path = settings.MEDIA_ROOT + obj.file_path
if 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_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
return Response(result, status.HTTP_200_OK)
except Exception as e:
result['msg'] = '%s' % e
result['success'] = False
return 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：
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.urls import 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