Django 实现文件上传下载API

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

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'))

]

# 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);

 

            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):