如何使用nodejs / express上传和读取文件
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how to upload and read a file with nodejs / express
提问by Simply Seth
there are all kinds of posts about this, but I'm still not getting it. I want to upload a *.csv and read and process its contents.
有各种各样的帖子关于这个，但我仍然没有得到它。我想上传 *.csv 并阅读和处理其内容。
my jade file is this
我的玉文件是这个
//views/import.jade
extends layout
block content
h1= title
form(action="/import", method="post", enctype="multipart/form-data")
input(type="file", name="ufile")
input(type="submit", name="Upload")
--
——
I changed the code, but req.files is undefined
我更改了代码，但 req.files 未定义
//routes/index.js
/* import page. */
router.get('/blah', function(req, res, next) {
res.render('import', { title: 'Import Data' });
});
router.post('/import', function(req, res) {
console.log(req.files);
});
module.exports = router;
采纳答案by Simply Seth
The below tutorial gets me super close to where I need to be.
下面的教程让我非常接近我需要去的地方。
NOTE: In the form, it should be:
注意：在表格中，它应该是：
action="/uploads/upload"
I can finally upload and read *.csv files.
我终于可以上传和读取 *.csv 文件了。
http://blog.e-zest.com/how-to-handle-file-upload-with-node-and-express-4-0/
http://blog.e-zest.com/how-to-handle-file-upload-with-node-and-express-4-0/
Here is one of the secret ingredients for reading form data:
这是读取表单数据的秘诀之一：
https://github.com/expressjs/multer
https://github.com/expressjs/multer
I hope this may be of use to someone else who was stuck like me (for 3 days!).
我希望这对像我一样被卡住的其他人有用（3 天！）。
回答by Vino
Convert the uploaded file in to string, using
将上传的文件转换为字符串，使用
toString('utf8')
toString('utf8')
you can than make any operation on string like convert it to json using csvtojsonpackage
您可以对字符串进行任何操作，例如使用csvtojson包将其转换为 json
Here is the sample code for uploading csv and than convert to json-
这是上传csv然后转换为json的示例代码-
/* csv to json */
const express = require("express"),
app = express(),
upload = require("express-fileupload"),
csvtojson = require("csvtojson");
let csvData = "test";
app.use(upload());
app.get("/", (req, res, next) => {
res.sendFile(__dirname + "/index.html");
});
app.post("/file", (req, res) => {
/** convert req buffer into csv string ,
* "csvfile" is the name of my file given at name attribute in input tag */
csvData = req.files.csvfile.data.toString('utf8');
return csvtojson().fromString(csvData).then(json =>
{return res.status(201).json({csv:csvData, json:json})})
});
app.listen(process.env.PORT || 4000, function(){
console.log('Your node js server is running');
});
working example- csvjsonapi
工作示例 - csvjsonapi
回答by Despertaweb
Hope this solves your question, this is my method to multiple upload file:
希望这能解决您的问题，这是我的多个上传文件的方法：
Nodejs :
节点：
router.post('/upload', function(req , res) {
var multiparty = require('multiparty');
var form = new multiparty.Form();
var fs = require('fs');
form.parse(req, function(err, fields, files) {
var imgArray = files.imatges;
for (var i = 0; i < imgArray.length; i++) {
var newPath = './public/uploads/'+fields.imgName+'/';
var singleImg = imgArray[i];
newPath+= singleImg.originalFilename;
readAndWriteFile(singleImg, newPath);
}
res.send("File uploaded to: " + newPath);
});
function readAndWriteFile(singleImg, newPath) {
fs.readFile(singleImg.path , function(err,data) {
fs.writeFile(newPath,data, function(err) {
if (err) console.log('ERRRRRR!! :'+err);
console.log('Fitxer: '+singleImg.originalFilename +' - '+ newPath);
})
})
}
})
Make sure your form has enctype="multipart/form-data"
确保您的表单具有 enctype="multipart/form-data"
I hope this gives you a hand ;)
我希望这能帮到你 ;)
