文件上传程序给错误

http://planetcakephp.org/aggregator/items/3241-streaming-file-uploads-with-nodejs

var http = require('http'); 
var multipart = require('./multipart'); 
var sys = require('sys'); 

var server = http.createServer(function(req, res) { 
    console.log('in upload files'+req.url); 

    switch (req.url) { 
    case '/': 
     display_form(req, res); 
     break; 
    case '/upload': 
     upload_file(req, res); 
     break; 
    default: 
     show_404(req, res); 
     break; 
    } 
}); 
server.listen(8000); 

function display_form(req, res) { 
    res.writeHead(200, {'Content-Type': 'text/html'}); 
    res.end(
    '<form action="/upload" method="post" enctype="multipart/form-data">'+ 
    '<input type="file" name="upload-file">'+ 
    '<input type="submit" value="Upload">'+ 
    '</form>' 
); 

} 

function upload_file(req, res) { 
    console.log('in upload files'); 
    req.setEncoding('binary'); 

    var stream = new multipart.Stream(req); 
    stream.addListener('part', function(part) { 
    console.log('in upload files1'); 
    part.addListener('body', function(chunk) { 
     console.log('in upload files2'); 
     var progress = (stream.bytesReceived/stream.bytesTotal * 100).toFixed(2); 
     var mb = (stream.bytesTotal/1024/1024).toFixed(1); 

     sys.print("Uploading "+mb+"mb ("+progress+"%)\015"); 

     // chunk could be appended to a file if the uploaded file needs to be saved 
    }); 
    }); 
    stream.addListener('complete', function() { 
    res.writeHead(200, {'Content-Type': 'text/plain'}); 
    res.write('Thanks for playing!'); 
    res.end(); 
    sys.puts("\n=> Done"); 
    }); 
} 

function show_404(req, res) { 
    res.writeHead(404, {'Content-Type': 'text/plain'}); 
    res.write('You r doing it rong!'); 
    res.end(); 
}

错误给人是：

[email protected]:~/rahul$ node test.js 
in upload files/ 
in upload files/upload 
in upload files 

/home/reach121/rahul/test.js:37 
    var stream = new multipart.Stream(req); 
      ^
TypeError: undefined is not a function 
    at CALL_NON_FUNCTION_AS_CONSTRUCTOR (native) 
    at upload_file (/home/reach121/rahul/test.js:37:16) 
    at Server.<anonymous> (/home/reach121/rahul/test.js:13:7) 
    at Server.emit (events.js:67:17) 
    at HTTPParser.onIncoming (http.js:1108:12) 
    at HTTPParser.onHeadersComplete (http.js:108:31) 
    at Socket.ondata (http.js:1007:22) 
    at Socket._onReadable (net.js:678:27) 
    at IOWatcher.onReadable [as callback] (net.js:177:10)

请说明为什么这个错误即将到来。

来源

2011-04-26 XMen