我使用axios的基本http请求,如GET和POST,它工作得很好。现在我需要能够下载Excel文件。这在axios中可行吗?如果是,谁有一些示例代码?如果不是,我还可以在React应用程序中使用什么来做同样的事情?


当前回答

这对我很管用。我在reactJS中实现了这个解决方案

const requestOptions = {`enter code here`
method: 'GET',
headers: { 'Content-Type': 'application/json' }
};

fetch(`${url}`, requestOptions)
.then((res) => {
    return res.blob();
})
.then((blob) => {
    const href = window.URL.createObjectURL(blob);
    const link = document.createElement('a');
    link.href = href;
    link.setAttribute('download', 'config.json'); //or any other extension
    document.body.appendChild(link);
    link.click();
})
.catch((err) => {
    return Promise.reject({ Error: 'Something Went Wrong', err });
})

其他回答

我有一个问题,我从axios const axiosResponse = await axios.get(pdf.url)传输到谷歌驱动器googleDrive.files。create({media: {body: axiosResponse.)data, mimeType}, requestBody: {name: fileName, parents: [parentFolder], mimeType}, auth: jwtClient})上传一个损坏的文件。

文件损坏的原因是axios转换了axiosResponse。数据转换为字符串。为了解决这个问题,我必须要求axios返回一个axios.get流。url, {responseType: 'stream'})。

使用URL.CreateObject()的答案对我来说工作得很好。 我仍然想指出使用HTTP报头的选项。

使用HttpHeaders有以下优点:

广泛的浏览器支持 不需要在浏览器的内存中创建一个blob对象 在显示给用户反馈之前,不需要等待服务器的完整响应吗 无尺寸限制

使用HttpHeaders需要你访问下载文件的后端服务器(这似乎是OP的Excel文件的情况)

HttpHeaders解决方案:

前端:

//... 
// the download link
<a href="download/destination?parameter1=foo&param2=bar"> 
click me to download!
</a>

后端

(本例中是c#,但也可以是任何语言。根据需要进行调整)

...
var fs = new FileStream(filepath, FileMode.OpenOrCreate, FileAccess.Read);
Response.Headers["Content-Disposition"] = "attachment; filename=someName.txt";
return File(fs, "application/octet-stream");
...

此解决方案假定您可以控制响应的后端服务器。

https://github.com/eligrey/FileSaver.js/wiki/Saving-a-remote-file#using-http-header

        axios.get(
            '/app/export'
        ).then(response => {    
            const url = window.URL.createObjectURL(new Blob([response]));
            const link = document.createElement('a');
            link.href = url;
            const fileName = `${+ new Date()}.csv`// whatever your file name .
            link.setAttribute('download', fileName);
            document.body.appendChild(link);
            link.click();
            link.remove();// you need to remove that elelment which is created before.
})

有几个关键点大部分答案都被忽略了。

我将在这里进行更深入的解释。

TLDR;

如果您正在创建一个标记链接并通过浏览器请求启动下载,那么

总是调用window.URL.revokeObjectURL(url);。否则就会有 不必要的内存尖峰。 不需要使用document.body. appendchild (link);将创建的链接附加到文档主体,从而避免以后不必要地删除子链接。


有关组件代码和更深入的分析,请进一步阅读

首先要弄清楚试图从中下载数据的API端点是公共的还是私有的。你能控制服务器吗?


如果服务器响应

Content-Disposition: attachment; filename=dummy.pdf
Content-Type: application/pdf

浏览器总是会尝试下载名称为'dummy.pdf'的文件


如果服务器响应

Content-Disposition: inline; filename=dummy.pdf
Content-Type: application/pdf

浏览器将首先尝试打开一个本地文件阅读器,如果名称为'dummy.pdf',否则它将开始下载文件。


如果服务器没有响应以上两个头

如果没有设置下载属性,浏览器(至少chrome)将尝试打开该文件。如果设置,它将下载文件。在url不是blob的情况下,文件名将是最后一个路径参数的值。


除此之外,请记住使用transfer - encoding:从服务器传输大量数据。这将确保客户端知道在缺少Content-Length报头的情况下何时停止读取当前请求

私人档案

import { useState, useEffect } from "react";
import axios from "axios";

export default function DownloadPrivateFile(props) {
  const [download, setDownload] = useState(false);

  useEffect(() => {
    async function downloadApi() {
      try {
        // It doesn't matter whether this api responds with the Content-Disposition header or not
        const response = await axios.get(
          "http://localhost:9000/api/v1/service/email/attachment/1mbdoc.docx",
          {
            responseType: "blob", // this is important!
            headers: { Authorization: "sometoken" },
          }
        );
        const url = window.URL.createObjectURL(new Blob([response.data])); // you can mention a type if you wish
        const link = document.createElement("a");
        link.href = url;
        link.setAttribute("download", "dummy.docx"); //this is the name with which the file will be downloaded
        link.click();
        // no need to append link as child to body.
        setTimeout(() => window.URL.revokeObjectURL(url), 0); // this is important too, otherwise we will be unnecessarily spiking memory!
        setDownload(false);
      } catch (e) {} //error handling }
    }

    if (download) {
      downloadApi();
    }
  }, [download]);

  return <button onClick={() => setDownload(true)}>Download Private</button>;
}


公共档案

import { useState, useEffect } from "react";
export default function DownloadPublicFile(props) {
  const [download, setDownload] = useState(false);

  useEffect(() => {
    if (download) {
      const link = document.createElement("a");
      link.href =
        "http://localhost:9000/api/v1/service/email/attachment/dummy.pdf";
      link.setAttribute("download", "dummy.pdf");
      link.click();
      setDownload(false);
    }
  }, [download]);

  return <button onClick={() => setDownload(true)}>Download Public</button>;
}

很高兴知道:

Always control file downloads from server. Axios in the browser uses XHR under the hood, in which streaming of responses is not supported. Use onDownloadProgress method from Axios to implement progress bar. Chunked responses from server do not ( cannot ) indicate Content-Length. Hence you need some way of knowing the response size if you are using them while building a progress bar. <a> tag links can only make GET HTTP requests without any ability to send headers or cookies to the server (ideal for downloading from public endpoints) Brower request is slightly different from XHR request made in code.

参考:AJAX请求和常规浏览器请求之间的区别

你需要返回File({file_to_download}, "application/vnd.ms-excel")从后端到前端,在你的js文件中,你需要更新下面写的代码:

function exportToExcel() {
        
        axios.post({path to call your controller}, null,
            {
                headers:
                {
                    'Content-Disposition': "attachment; filename=XYZ.xlsx",
                    'Content-Type': 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet'
                },
                responseType: 'arraybuffer',
            }
        ).then((r) => {
            const path= window.URL.createObjectURL(new Blob([r.data]));
            const link = document.createElement('a');
            link.href = path;
            link.setAttribute('download', 'XYZ.xlsx');
            document.body.appendChild(link);
            link.click();
        }).catch((error) => console.log(error));
    }