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  • Django 实现文件上传下载API

    Django 实现文件上传下载API

     

    by:授客 QQ1033553122 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.
     
     
    # 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 

     

     

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  • 原文地址:https://www.cnblogs.com/shouke/p/13586831.html
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