处理我必须接受上传文件的路径:不确定错误快递
在app.js
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var upload = require('./routes/upload');
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app.use('/upload', upload);
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/* Need to start the application with NODE_ENV=production */
app.use(function (err, req, res, next){
if (res.headersSent) {
return next(err)
}
res.status(500)
res.render('An error occured while trying to serve your request. Please send us an email if the error recurs.')
});
app.listen(3000);
而且在路线/ upload.js,我接受文件前检查文件类型和在数据库中创建一个条目。我还检查文件写入错误时,我试图通过调用next(ERR)内handleFileUpload传递到app.js错误处理程序,如下图所示:
var express = require('express');
var router = express.Router();
var path = require('path');
var mysql = require('mysql');
var multer = require('multer');
var fs = require('fs');
var db = require('../database');
var MAGIC_NUMBERS = {
jpg: 'ffd8ffe0',
jpg1: 'ffd8ffe1',
png: '89504e47'
}
/* Adapted from https://evdokimovm.github.io/javascript/nodejs/expressjs/multer/2016/11/03/Upload-files-to-server-using-NodeJS-and-Multer-package-filter-upload-files-by-extension.html */
function checkMagicNumbers(magic) {
if (magic == MAGIC_NUMBERS.jpg || magic == MAGIC_NUMBERS.jpg1 || magic == MAGIC_NUMBERS.png)
return true;
}
function handleFileUpload(req, res, next){
var upload = multer({
storage: multer.memoryStorage(),
}).single('fileUpload');
upload(req, res, function(err) {
var buffer = req.file.buffer;
var magic = buffer.toString('hex', 0, 4);
var filename = req.file.fieldname + '-' + req.file.originalname.replace(/\s+/g,'') + '-' + Date.now() + path.extname(req.file.originalname);
if (checkMagicNumbers(magic)) {
fs.writeFile('/uploads/' + filename, buffer, 'binary', function(err) {
if (err){
console.log(err);
return next(err);
}
else{
req.savedfilename = filename;
next();
}
})
} else {
res.end('File is not of the following accepted types: jpeg, jpg, png.');
}
});
}
function handleDatabaseInsert(req, res, next)
{
db.insertRecord(req.body.name, req.body.email, req.body.message,
req.body.country, req.savedfilename, function(err, results){
if(err)
next(err);
});
res.end("Thank you for your participation! Please look forward to our email with updates.");
}
/* POST to Upload */
router.post('/', handleFileUpload, handleDatabaseInsert)
module.exports = router;
的问题是,当我试图赶上尝试写入文件并将其传递到app.js中的错误处理程序时,可能会发生错误,该错误处理程序在handleFileUpload内部,将调用下一个中间件handleDatabaseInsert,而不是使应用程序在app.js结束前使用的错误处理程序我让应用程序听。
这是预期的行为?我认为具有4个形式参数的函数将被调用来处理错误?
注:我故意用一个不存在的文件路径模拟写入错误,在这种情况下/上载/而不是./uploads/
谢谢!
我下面这个页面描述的错误处理机制:[错误在快速处理(HTTP:/ /expressjs.com/en/guide/error-handling.html)。因为它说调用next()以外的任何参数都会将该请求视为错误,并调用错误处理路由。我在app.js中有一个全局错误处理路线,并希望路线能够处理它。但我想我现在要通过使用res.end()来解决这个问题。 – mod0