使用fetch、multer、express将blob数据发送到节点

Question

尝试发送blob对象到我的节点服务器。在客户端，我正在使用MediaRecorder录制一些音频，然后我想将文件发送到服务器进行处理。

      saveButton.onclick = function(e, audio) {
        var blobData = localStorage.getItem('recording');
        console.log(blobData);
        var fd = new FormData();
        fd.append('upl', blobData, 'blobby.raw');
        fetch('/api/test',
          {
            method: 'post',
            body: fd
          })
        .then(function(response) {
          console.log('done');
          return response;
        })
        .catch(function(err){ 
          console.log(err);
        });
      }

这是我的快车路线，它使用multer:

  var upload = multer({ dest: __dirname + '/../public/uploads/' });
  var type = upload.single('upl');
  app.post('/api/test', type, function (req, res) {
    console.log(req.body);
    console.log(req.file);
    // do stuff with file
  });

但是我的日志没有返回任何东西:

{ upl: '' }
undefined

花了很长时间在这个所以任何帮助感激!

Answer 1

我只能运行你上面例子的最小配置，它对我来说工作得很好。

服务器:

var express = require('express');
var multer  = require('multer');
var app = express();
app.use(express.static('public')); // for serving the HTML file
var upload = multer({ dest: __dirname + '/public/uploads/' });
var type = upload.single('upl');
app.post('/api/test', type, function (req, res) {
   console.log(req.body);
   console.log(req.file);
   // do stuff with file
});
app.listen(3000);

HTML文件在public:

<script>
var myBlob = new Blob(["This is my blob content"], {type : "text/plain"});
console.log(myBlob);
// here unnecessary - just for testing if it can be read from local storage
localStorage.myfile = myBlob;
var fd = new FormData();
fd.append('upl', localStorage.myfile, 'blobby.txt');
fetch('/api/test',
{
    method: 'post',
    body: fd
}); 
</script>

前端的console.log(myBlob);正在打印Blob {size: 23, type: "text/plain"}。后端打印:

{}
{ fieldname: 'upl',
  originalname: 'blobby.txt',
  encoding: '7bit',
  mimetype: 'text/plain',
  destination: '/var/www/test/public/uploads/',
  filename: 'dc56f94d7ae90853021ab7d2931ad636',
  path: '/var/www/test/public/uploads/dc56f94d7ae90853021ab7d2931ad636',
  size: 23 }

也可以尝试使用硬编码的Blob，如本例中用于调试目的。

Answer 2

不需要使用multer。在app.post()中使用express.raw()

var express = require('express');
var app = express();
app.use(express.static('public')); // for serving the HTML file
app.post('/api/test', express.raw({type: "*/*"}), function (req, res) {
   console.log(req.body);
   // do stuff with file
});
app.listen(3000);