将图像上传到 Node.js使用 multer 不起作用

Upload images to Node.js using multer doesn't work

本文关键字：js 使用 multer 不起作用 Node 图像      更新时间：2023-09-26

我正在尝试将图像上传到节点.js快递

  1. bodyParser 需要一个中间件来处理图像文件，否则它会回复

令牌取消定义

  1. 我使用 Multer 作为中间件，正如所说，req.file 应该打孔一个信息数组，比我可以使用 req.file.image.path 来获取文件路径和其他信息，而不是我可以将其保存为文件。

这就是问题所在，我从邮递员上传了一张图片，我只写console.log(req.file)它显示了undefined.

如果我尝试编写req.file.image.path来获取文件路径，错误是image undefined，似乎我没有很好地使用multer，所以req.file没有保存数据信息，我应该创建一些临时文件夹来multer还是...？

应用.js

var  express = require('express')
    ,bodyParser = require('body-parser')
    ,app = express()
    ,multer  =  require('multer')
    ,binary = require('binary')
    ,fs = require('fs')
    ,util= require('util')
    ,http = require('http')
    ,multer = require('multer')
    ,upload = multer({ dest: '/Node/file-upload/uploads/' });
app.use(bodyParser.urlencoded({ extended: true })); // support encoded bodies.
app.use(bodyParser.json({limit: '5mb'}));

songs = require('./routes/route');
app.listen(3000, function () {
      console.log('Example app listening on port 3000!');
                          });
app.post('/upload',songs.upload);

路线.js

var mongoose = require('mongoose');
var uri = "mongodb://1111:1111@ds061365.mongolab.com:61365/aweitest";
mongoose.connect(uri);
// we're connected!
var db = mongoose.connection.db;
var BSON = require('bson').BSONPure;
var binary = require('binary');
var body = require('body-parser');
var fs = require('fs');
var multer = require('multer');
var storage =   multer.diskStorage({
      destination: function (req, file, callback) {
                   callback(null, '/Node/file-upload/uploads/');
                    },
      filename: function (req, file, callback) {
                   callback(null, file.fieldname + '-' + Date.now());
                   }
             });
 var upload = multer({ storage : storage}).single('image');

db.on('error', console.error.bind(console, 'connection errrrrrrrror:'));
db.once('open', function() {
      console.log("mongodb is connected!!");
      });
exports.upload = function(req, res) {
        upload(req,res,function(err) {
               console.log(req.file);
                 fs.readFile(req.file.image.path, function (err, data){
                      var dirname = "/Node/file-upload/uploads/";
                      var newPath = dirname + req.body.filename;
                 fs.writeFile(newPath, data, function (err) {
                     if(err) {
                         return res.end("Error uploading file.");
                            }
                                 res.end("File is uploaded");
                   });
             });
       });
  };

错误

 TypeError: Cannot read property 'image' of undefined
at c:'Users'awei'WebstormProjects'untitled'routes'girlshanlder.js:107:28

您需要在邮递员中发送图像之前设置文件名，如下所示

干杯。

用于在MySQL数据库和文件夹中上传图像的完整代码。

只需定义模块并安装 multer 和 path 并保存即可。

var multer = require('multer'); 
var path   = require('path');
var storage = multer.diskStorage({
    destination: function(req, file, callback) {
        callback(null, './uploadimages')
    },
    filename: function(req, file, callback) {
        callback(null, file.fieldname + '-' + Date.now() + path.extname(file.originalname))
    }
})
app.post('/imginsert',multer({
    storage: storage,
    fileFilter: function(req, file, callback) {
        var ext = path.extname(file.originalname)
        if (ext !== '.png' && ext !== '.jpg' && ext !== '.gif' && ext !== '.jpeg') 
                    {
            return callback(res.end('Only images are allowed'), null)
        }
        callback(null, true)
    }
}).single('img'), function(req, res) {
 /*img is the name that you define in the html input type="file" name="img" */       
        var data = {
            table_column_name(your database table column field name) :req.file
        };
        var query = connection.query("Insert into tablename set ?" ,data,function(err, rows)      
        {                                                      
          if (err)
             throw err;
         res.redirect('/blog');
        });
        console.log(query.sql);
        console.log(req.file);
    });
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