节点js multer文件上传不起作用。 req.file和req.files总是未定义的 [英] node js multer file upload not working. req.file and req.files always undefined

问题描述

我正在尝试将文件上传到我的服务器，但是 req.file 和 req.files 总是在我的POST REST端点上未定义。

I am trying to upload a file to my server, but req.file and req.files is always undefined on my POST REST endpoint.

我试图上传的内容是一个.dat文件，我期待一个json响应。

The content I'm trying to upload is a ".dat" file, and I am expecting a json response.

这是我的代码：

服务器端：

var express = require('express');
var multer  = require('multer')
var upload = multer({ dest: 'uploads/' })

var app = express()

app.post('/creoUpload', upload.single('uploadFileField'), function(req, res, next) {
  console.log("req.file = ",JSON.stringify(req.file)); //is undefined
  console.log("req.files = ",JSON.stringify(req.files)); //also undefined
});

客户端：

<form id="creoUploadForm" action="/creoUpload" enctype="multipart/form-data" method="post">
    <input type='file' name='uploadFileField'><br><br>
    <input type='submit' value='Upload'/>
</form>

JS：

$( "#creoUploadForm" ).submit(function( event ) {
    event.preventDefault();
    var formData = new FormData($(this)[0]);
    $.ajax({
          url: '/creoUpload',
          type: 'POST',
          data: formData,
          async: true,
          cache: false,
          contentType: false,
          processData: false,
          success: function (returndata) {
              console.log("RETURN DATA IS: ",returndata);
          },
          error: function (err) {
              console.log("ERROR: ",err);
          }
    });
});

我一直在玩这些字段，但它不起作用..有人看到我做错了什么在这里？

I keep playing around with the fields but it's not working.. anyone see what I'm doing wrong here?

我正在关注中的示例https://www.npmjs.com/package/multer

版本：

Versions:

• 快递版本：4.12.0


• 节点版本：6.5.0


• JQuery：1.12.1

谢谢！

推荐答案

您正在使用multer作为中间件，因此在进入您的功能并打印之前，它已将图像上传到存储并从 req.files 中删除记录。

You are using multer as a middleware, So before entering into your function and printing it has uploaded images to storage and removes record from req.files.

有两种方法可以访问req.files。

There are two ways you can access req.files.

1. 使用multer作为 finw3 所述的函数。

另一个解决方案是：

//代码开始

var storage = multer.diskStorage({

  destination: function (req, file, cb) {

    cb(null, '/filepath')
  },


  filename: function (req, file, cb) {

    let filename = 'filenametogive';
     req.body.file = filename

    cb(null, filename)
  }
})

var upload = multer({ storage: storage })

//代码结束

现在您可以访问req.body.file

Now you can access files in req.body.file

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