一、概述
在项目中，点击下载按钮，就可以下载文件。
传统的下载链接一般是get方式，这种链接是公开的，可以任意下载。
在实际项目，某些下载链接，是私密的。必须使用post方式，传递正确的参数，才能下载。
二、django项目
本环境使用django 3.1.5，新建项目download_demo
安装模块
代码语言：javascript复制pip3 install djangorestframework django-cors-headers修改文件download_demo/settings.py
代码语言：javascript复制INSTALLED_APPS = [
'django.contrib.admin',
'django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.messages',
'django.contrib.staticfiles',
'api.apps.ApiConfig',
'corsheaders', # 注册应用cors
]注册中间件
代码语言：javascript复制MIDDLEWARE = [
'django.middleware.security.SecurityMiddleware',
'django.contrib.sessions.middleware.SessionMiddleware',
'django.middleware.common.CommonMiddleware',
'django.middleware.csrf.CsrfViewMiddleware',
'django.contrib.auth.middleware.AuthenticationMiddleware',
'django.contrib.messages.middleware.MessageMiddleware',
'django.middleware.clickjacking.XFrameOptionsMiddleware',
'corsheaders.middleware.CorsMiddleware', # 注册组件cors
]最后一行增加
代码语言：javascript复制# 跨域增加忽略
CORS_ALLOW_CREDENTIALS = True
CORS_ORIGIN_ALLOW_ALL = True
CORS_ALLOW_METHODS = (
'GET',
'OPTIONS',
'PATCH',
'POST',
'VIEW',
)
CORS_ALLOW_HEADERS = (
'XMLHttpRequest',
'X_FILENAME',
'accept-encoding',
'authorization',
'content-type',
'dnt',
'origin',
'user-agent',
'x-csrftoken',
'x-requested-with',
'Pragma',
)修改download_demo/urls.py
代码语言：javascript复制from django.contrib import admin
from django.urls import path
from api import views
urlpatterns = [
path('admin/', admin.site.urls),
path('download/excel/', views.ExcelFileDownload.as_view()),
]修改api/views.py
代码语言：javascript复制from django.shortcuts import render,HttpResponse
from download_demo import settings
from django.utils.encoding import escape_uri_path
from django.http import StreamingHttpResponse
from django.http import JsonResponse
from rest_framework.views import APIView
from rest_framework import status
import os
class ExcelFileDownload(APIView):
def post(self,request):
print(request.data)
# filename = "大江大河.xlsx"
filename = request.data.get("filename")
download_file_path = os.path.join(settings.BASE_DIR, "upload",filename)
print("download_file_path",download_file_path)
response = self.big_file_download(download_file_path, filename)
if response:
return response
return JsonResponse({'status': 'HttpResponse', 'msg': 'Excel下载失败'})
def file_iterator(self,file_path, chunk_size=512):
"""
文件生成器,防止文件过大，导致内存溢出
:param file_path: 文件绝对路径
:param chunk_size: 块大小
:return: 生成器
"""
with open(file_path, mode='rb') as f:
while True:
c = f.read(chunk_size)
if c:
yield c
else:
break
def big_file_download(self,download_file_path, filename):
try:
response = StreamingHttpResponse(self.file_iterator(download_file_path))
# 增加headers
response['Content-Type'] = 'application/octet-stream'
response['Access-Control-Expose-Headers'] = "Content-Disposition, Content-Type"
response['Content-Disposition'] = "attachment; filename={}".format(escape_uri_path(filename))
return response
except Exception:
return JsonResponse({'status': status.HTTP_400_BAD_REQUEST, 'msg': 'Excel下载失败'},
status=status.HTTP_400_BAD_REQUEST)在项目根目录创建upload文件
里面放一个excel文件，比如：大江大河.xlsx
三、vue项目
新建一个vue项目，安装ElementUI 模块即可。
新建test.vue
代码语言：javascript复制<template>
<div style="width: 70%;margin-left: 30px;margin-top: 30px;">
<el-button class="filter-item" type="success" icon="el-icon-download" @click="downFile()">下载</el-button>
</div>
</template>
<script>
import axios from 'axios'
export default {
data() {
return {
}
},
mounted: function() {
},
methods: {
downloadFile(url, options = {}){
return new Promise((resolve, reject) => {
// console.log(`${url} 请求数据，参数=>`, JSON.stringify(options))
// axios.defaults.headers['content-type'] = 'application/json;charset=UTF-8'
axios({
method: 'post',
url: url, // 请求地址
data: options, // 参数
responseType: 'blob' // 表明返回服务器返回的数据类型
}).then(
response => {
// console.log("下载响应",response)
resolve(response.data)
let blob = new Blob([response.data], {
type: 'application/vnd.ms-excel'
})
// console.log(blob)
// let fileName = Date.parse(new Date()) '.xlsx'
// 切割出文件名
let fileNameEncode = response.headers['content-disposition'].split("filename=")[1];
// 解码
let fileName = decodeURIComponent(fileNameEncode)
// console.log("fileName",fileName)
if (window.navigator.msSaveOrOpenBlob) {
// console.log(2)
navigator.msSaveBlob(blob, fileName)
} else {
// console.log(3)
var link = document.createElement('a')
link.href = window.URL.createObjectURL(blob)
link.download = fileName
link.click()
//释放内存
window.URL.revokeObjectURL(link.href)
}
},
err => {
reject(err)
}
)
})
},
// 下载文件
downFile(){
let postUrl= "http://127.0.0.1:8000/download/excel/"
let params = {
filename: "大江大河.xlsx",
}
// console.log("下载参数",params)
this.downloadFile(postUrl,params)
},
}
}
</script>
<style>
</style>注意：这里使用post请求，并将filename传输给api，用来下载指定的文件。
访问测试页面，点击下载按钮
就会自动下载
打开工具栏，查看响应信息
这里，就是django返回的文件名，浏览器下载保存的文件名，也是这个。
遇到中文，会进行URLcode编码。
所以在vue代码中，对Content-Disposition做了切割，得到了文件名。
