Django 实现文件上传下载API

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.


# 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 admin
from django.urls import path
 
from django.conf.urls import include
 
 
urlpatterns = [
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 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)

        # 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.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

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() 
            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 = [
#...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/