如何将多个映像从Android上传到NodeJS服务器

Question

我最近看到了一个从这里上传一些照片的教程[https://aguacatelang.wordpress.com/2012/08/19/android-multipart-upload-to-node-js/][1]

我刚刚学习了nodejs并且对编程语言的结构了解不足，我发现了这样的错误：

home/je/Documents/BE/UploadFoto/app.js:12
var db = new Db('photos', new dbServer('localhost', dbConnection.'27017', {}))
                                                                 ^^^^^^^
SyntaxError: Unexpected string
    at Module._compile (module.js:439:25)
    at Object.Module._extensions..js (module.js:474:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Function.Module.runMain (module.js:497:10)
    at startup (node.js:119:16)
    at node.js:935:3

这是原始源代码：

var express = require('express');

var app = express()

var fs = require('fs');
var im = require('imagemagick');

var Db = require('mongodb').Db;
var dbServer = require('mongodb').Server;
var dbConnection = require('mongodb').Connection;

var db = new Db('photos', new dbServer('localhost', dbConnection.'DEFAULT_PORT', {}));
db.open(function(err, db){});

app.use(express.bodyParser())

app.get('/', function(req, res){
    res.send(
        '<form action="/upload" method="post" enctype="multipart/form-data">'+
        '<input type="file" name="source">'+
        '<input type="submit" value="Upload">'+
        '</form>'
    );
});

app.post('/upload', function(req, res){
    console.log("Received file:\n" + JSON.stringify(req.files));

    var photoDir = __dirname+"/photos/";
    var thumbnailsDir = __dirname+"/photos/thumbnails/";
    var photoName = req.files.source.name;

    fs.rename(
        req.files.source.path,
        photoDir+photoName,
        function(err){
            if(err != null){
                console.log(err)
                res.send({error:"Server Writting No Good"});
            } else {
                im.resize(
                    {
                        srcData:fs.readFileSync(photoDir+photoName, 'binary'),
                        width:256
                    }, 
                    function(err, stdout, stderr){
                        if(err != null){
                            console.log('stdout : '+stdout)

                            res.send({error:"Resizeing No Good"});
                        } else {
                            //console.log('ELSE stdout : '+stdout)
                            fs.writeFileSync(thumbnailsDir+"thumb_"+photoName, stdout, 'binary');
                            res.send("Ok");
                        }
                    }
                );
            }
        }
    );
});

app.get('/info', function(req, res){
    console.log(__dirname);
    res.send("ok");
});

app.listen(8000);
console.log('connected to localhost....')

我将DEFAULT_PORT切换为27017，因为在我的PC中使用了mongodb的端口：localhost / 27017。愿有人帮帮我吗？谢谢