Question

我尝试向请求中带有图片的API发送POST请求。我正在使用请求模块执行此操作，但我尝试的所有内容都无法正常工作。我目前的代码：

const options = {
    method: "POST",
    url: "https://api.LINK.com/file",
    port: 443,
    headers: {
        "Authorization": "Basic " + auth,
        "Content-Type": "multipart/form-data"
    },
    form : {
        "image" : fs.readFileSync("./images/scr1.png")
    }
};

request(options, function (err, res, body) {
    if(err) console.log(err);
    console.log(body);
});

但请求因某些原因使用Content-Type: application/x-www-form-urlencoded ...我该如何解决这个问题？

Answer 1

正如documentation表单multipart/form-data中所述，请求正在使用form-data库。因此，您需要提供formData选项，而不是form选项。

const options = {
    method: "POST",
    url: "https://api.LINK.com/file",
    port: 443,
    headers: {
        "Authorization": "Basic " + auth,
        "Content-Type": "multipart/form-data"
    },
    formData : {
        "image" : fs.createReadStream("./images/scr1.png")
    }
};

request(options, function (err, res, body) {
    if(err) console.log(err);
    console.log(body);
});

Answer 2

对于request模块deprecated，请考虑使用form-data和核心http(s)模块。

有点冗长，但是您会获得较小的生产版本，这总是很好的，在无服务器环境中更是如此，因为它可以减少冷启动时间。

// abstract and promisify actual network request
async function makeRequest(formData, options) {
  return new Promise((resolve, reject) => {
    const req = formData.submit(options, (err, res) => {
      if (err) {
        return reject(new Error(err.message))
      }

      if (res.statusCode < 200 || res.statusCode > 299) {
        return reject(new Error(`HTTP status code ${res.statusCode}`))
      }

      const body = []
      res.on('data', (chunk) => body.push(chunk))
      res.on('end', () => {
        const resString = Buffer.concat(body).toString()
        resolve(resString)
      })
    })
  })
}

const formData = new FormData()

formData.append('comment', 'Some note attached to the submitted file')
formData.append('image', fs.createReadStream('./images/logo.png'))

const options = {
  host: 'postman-echo.com',
  path: '/post',
  method: 'POST',
  protocol: 'https:', // note : in the end
  headers: {
    Authorization: `Basic some-token-here`,
  },
}

const res = await makeRequest(formData, options)

Answer 3

恼火的是，针对该问题的几乎所有示例解决方案都包含第三方模块。我知道，简单地包括一个模块并复制/粘贴一个代码示例通常会更容易，但是对于这样的基本HTTP概念，实际上并不需要一个。添加模块可以快速增加您在AWS lambda等云环境中的占用空间，其中总解决方案文件大小会严重影响运行时性能。我在这里找到了这个有用的例子，

https://tanaikech.github.io/2017/07/27/multipart-post-request-using-node.js/

var fs = require('fs');
var request = require('request');
var upfile = 'sample.zip';
fs.readFile(upfile, function(err, content){
    if(err){
        console.error(err);
    }
    var metadata = {
        token: "### access token ###",
        channels: "sample",
        filename: "samplefilename",
        title: "sampletitle",
    };
    var url = "https://slack.com/api/files.upload";
    var boundary = "xxxxxxxxxx";
    var data = "";
    for(var i in metadata) {
        if ({}.hasOwnProperty.call(metadata, i)) {
            data += "--" + boundary + "\r\n";
            data += "Content-Disposition: form-data; name=\"" + i + "\"; \r\n\r\n" + metadata[i] + "\r\n";
        }
    };
    data += "--" + boundary + "\r\n";
    data += "Content-Disposition: form-data; name=\"file\"; filename=\"" + upfile + "\"\r\n";
    data += "Content-Type:application/octet-stream\r\n\r\n";
    var payload = Buffer.concat([
            Buffer.from(data, "utf8"),
            new Buffer(content, 'binary'),
            Buffer.from("\r\n--" + boundary + "--\r\n", "utf8"),
    ]);
    var options = {
        method: 'post',
        url: url,
        headers: {"Content-Type": "multipart/form-data; boundary=" + boundary},
        body: payload,
    };
    request(options, function(error, response, body) {
        console.log(body);
    });
});

希望对其他人有帮助！

NodeJS请求如何发送multipart / form-data POST请求

3 个答案: