app.js 主文件中的 toString 未定义 - NodeJS

Question

我正在尝试获取上传文件的文件名，但在 nodejs 的主应用程序文件中进行如下所示的字符串操作时出现错误：

var fileName = file.split('path:')[1]
    .split('\',')[0]
    .split(dir)[1]
    .toString()
    .replace(/\/g, '')
    .replace(/\//g, '');

我在 .toString() 遇到错误，不知道为什么。

错误堆栈跟踪

TypeError: Cannot read property 'toString' of undefined
    at C:\Users\murli\NodeProjects\SpeechExpress\app.js:57:76
    at IncomingForm.<anonymous> (C:\Users\murli\NodeProjects\SpeechExpress\node_modules\formidable\lib\incoming_form.js:105:9)
    at emitNone (events.js:86:13)
    at IncomingForm.emit (events.js:185:7)
    at IncomingForm._maybeEnd (C:\Users\murli\NodeProjects\SpeechExpress\node_modules\formidable\lib\incoming_form.js:553:8)
    at C:\Users\murli\NodeProjects\SpeechExpress\node_modules\formidable\lib\incoming_form.js:230:12
    at WriteStream.<anonymous> (C:\Users\murli\NodeProjects\SpeechExpress\node_modules\formidable\lib\file.js:74:5)
    at WriteStream.g (events.js:291:16)
    at emitNone (events.js:91:20)
    at WriteStream.emit (events.js:185:7)

代码

app.use('/uploadFile', function(request, response){

     // parse a file upload
    var mime = require('mime');
    var formidable = require('formidable');
    var util = require('util');

    var form = new formidable.IncomingForm();

    var dir = !!process.platform.match(/^win/) ? '\public\uploads\' : '/public/uploads/';

    form.uploadDir = __dirname + dir;
    console.log("Test 99: " + form.uploadDir);
    form.keepExtensions = true;
    form.maxFieldsSize = 10 * 1024 * 1024;
    form.maxFields = 1000;
    form.multiples = false;
    console.log("Test 100: ");

    form.parse(request, function(err, fields, files) {

        var file = util.inspect(files);
        console.log("form parse file: "+file + "\n" + files);

        response.writeHead(200, getHeaders('Content-Type', 'application/json'));


        var fileName = file.split('path:')[1].split('\',')[0].split(dir)[1].toString().replace(/\/g, '').replace(/\//g, '');
        var fileURL = 'http://' + app.address + ':' + port + '/public/uploads/' + fileName;

        console.log('fileURL: ', fileURL);

        response.write(JSON.stringify({
            fileURL: fileURL
        }));

        response.end();
    });

});

文件内容

{ file:
   File {
     domain: null,
     _events: {},
     _eventsCount: 0,
     _maxListeners: undefined,
     size: 114898,
     path: 'C:\Users\username\NodeProjects\SpeechExpress\public\uploads\upload_3c927e85105d0fd5d873e84952821531.webm',
     name: '1234.webm',
     type: 'video/webm',
     hash: null,
     lastModifiedDate: 2017-09-19T22:18:03.330Z,
     _writeStream:
      WriteStream {
        _writableState: [Object],
        writable: false,
        domain: null,
        _events: {},
        _eventsCount: 0,
        _maxListeners: undefined,
        path: 'C:\Users\username\NodeProjects\SpeechExpress\public\uploads\upload_3c927e85105d0fd5d873e84952821531.webm',
        fd: null,
        flags: 'w',
        mode: 438,
        start: undefined,
        autoClose: true,
        pos: undefined,
        bytesWritten: 114898,
        closed: true } } }

我需要的就是这个

upload_3c927e85105d0fd5d873e84952821531.webm

由此

C:\Users\username\NodeProjects\SpeechExpress\public\uploads\upload_3c927e85105d0fd5d873e84952821531.webm

Answer 1

喜欢这样

var f = File.path.split('\');
var fileName = f[f.length-1];

Answer 2

用path.basename有什么不省心的呢？

From the docs:

var path = require('path');

path.basename('/foo/bar/baz/asdf/quux.html');
// Returns: 'quux.html'

path.basename('/foo/bar/baz/asdf/quux.html', '.html');
// Returns: 'quux'

Answer 3

All I need is this

upload_3c927e85105d0fd5d873e84952821531.webm

from this

C:\Users\username\NodeProjects\SpeechExpress\public\uploads\upload_3c927e85105d0fd5d873e84952821531.webm

然后简单地：

let path = 'C:\Users\username\NodeProjects\SpeechExpress\public\uploads\upload_3c927e85105d0fd5d873e84952821531.webm',
    filename = path.split('\').pop();

并用正确的引用替换 path

Answer 4

我建议你使用正则表达式来处理它。

E:G

let file = 'C:\Users\username\NodeProjects\SpeechExpress\public\uploads\upload_3c927e85105d0fd5d873e84952821531.webm'
let fileName = file.match(/upload_\w+.webm$/)[0];
let fileURL = 'http://' + app.address + ':' + port + '/public/uploads/' + fileName;

// ....The rest of the code.

Answer 5

你好像用的是node，所以我建议你使用官方的路径对象：

const path = require("path")

const myFileName = "C:\Users\username\NodeProjects\SpeechExpress\public\uploads\upload_3c927e85105d0fd5d873e84952821531.webm"
const unixFile = "/home/test/jhgfd.h"
const obj = path.parse(myFileName)
console.log(obj.name)
console.log(obj)

最好的是它也适用于 Linux。您想要的属性名为名称。

Answer 6

这个问题有 2 个问题。

首先是如何从完整的目录字符串中提取文件名。因为你使用 node.js，它带有一个方便的函数 path.basename(filename).

第二个问题，首先是如何获取路径。 Formidable 提供文件，这是一个包含所有文件的简单对象字面量。您的文件输入名称似乎被称为 file,.. 所以要访问路径，您只需执行 files.file.path.

所以在结合这两个之后我们有.. path.basename(files.file.path)，你应该得到你的文件名，在这种情况下是 -> upload_3c927e85105d0fd5d873e84952821531.webm

app.js 主文件中的 toString 未定义 - NodeJS

toString undefined in app.js main file - NodeJS

javascript

node.js

formidable

错误堆栈跟踪

代码

文件内容