在Node.js中使用HTTP上传文件的方法

// The required modules  var express = require('express');  var formidable = require('formidable');  var fs = require('fs-extra');  var path = require('path'); var crypto = require('crypto');

// Serve up the Default.html page app.use(express.static(__dirname, { index: 'Default.html' }));   // Startup the express.js application app.listen(process.env.PORT || 1337);   // Path to save the files var uploadpath = 'C:/Uploads/CelerFT/';

// Use the post method for express.js to respond to posts to the uploadchunk urls and // save each file chunk as a separate file app.post('*/api/CelerFTFileUpload/UploadChunk*', function(request,response) {    if (request.method === 'POST') {    // Check Content-Type    if (!(request.is('multipart/form-data'))){     response.status(415).send('Unsupported media type');     return;    }     // Check that we have not exceeded the maximum chunk upload size   var maxuploadsize =51 * 1024 * 1024;     if (request.headers['content-length']> maxuploadsize){     response.status(413).send('Maximum upload chunk size exceeded');     return;    }

// Get the extension from the file name var extension =path.extname(request.param('filename'));   // Get the base file name var baseFilename =path.basename(request.param('filename'), extension);   // Create the temporary file name for the chunk var tempfilename =baseFilename + '.'+  request.param('chunkNumber').toString().padLeft('0', 16) + extension + ".tmp";    // Create the temporary directory to store the file chunk // The temporary directory will be based on the file name var tempdir =uploadpath + request.param('directoryname')+ '/' + baseFilename;   // The path to save the file chunk var localfilepath =tempdir + '/'+ tempfilename;   if (fs.ensureDirSync(tempdir)) {   console.log('Created directory ' +tempdir); }

// Check if we have uploaded a hand crafted multipart/form-data request // If we have done so then the data is sent as a base64 string // and we need to extract the base64 string and save it if (request.headers['celerft-encoded']=== 'base64') {    var fileSlice = newBuffer(+request.headers['content-length']);   var bufferOffset = 0;    // Get the data from the request  request.on('data', function (chunk) {    chunk.copy(fileSlice , bufferOffset);    bufferOffset += chunk.length;   }).on('end', function() {    // Convert the data from base64 string to binary   // base64 data in 4th index of the array   var base64data = fileSlice.toString().split('/r/n');    var fileData = newBuffer(base64data[4].toString(), 'base64');     fs.outputFileSync(localfilepath,fileData);    console.log('Saved file to ' +localfilepath);     // Send back a sucessful response with the file name   response.status(200).send(localfilepath);    response.end();   }); }

else {   // The data is uploaded as binary data.   // We will use formidable to extract the data and save it   var form = new formidable.IncomingForm();   form.keepExtensions = true;   form.uploadDir = tempdir;    // Parse the form and save the file chunks to the   // default location   form.parse(request, function (err, fields, files) {    if (err){     response.status(500).send(err);     return;    }    //console.log({ fields: fields, files: files });   });    // Use the filebegin event to save the file with the naming convention   /*form.on('fileBegin', function (name, file) {  file.path = localfilepath; });*/   form.on('error', function (err) {    if (err){     response.status(500).send(err);     return;    }   });    // After the files have been saved to the temporary name   // move them to the to teh correct file name   form.on('end', function (fields,files) {    // Temporary location of our uploaded file      var temp_path = this.openedFiles[0].path;     fs.move(temp_path , localfilepath,function (err){      if (err) {      response.status(500).send(err);      return;     }     else {      // Send back a sucessful response with the file name      response.status(200).send(localfilepath);      response.end();     }    });   });   // Send back a sucessful response with the file name  //response.status(200).send(localfilepath);  //response.end();  } }

// Request to merge all of the file chunks into one file app.get('*/api/CelerFTFileUpload/MergeAll*', function(request,response) {    if (request.method === 'GET') {     // Get the extension from the file name   var extension =path.extname(request.param('filename'));     // Get the base file name   var baseFilename =path.basename(request.param('filename'), extension);     var localFilePath =uploadpath + request.param('directoryname')+ '/' + baseFilename;     // Check if all of the file chunks have be uploaded   // Note we only wnat the files with a *.tmp extension   var files =getfilesWithExtensionName(localFilePath, 'tmp')    /*if (err) {    response.status(500).send(err);    return;   }*/    if (files.length !=request.param('numberOfChunks')){     response.status(400).send('Number of file chunks less than total count');     return;    }     var filename =localFilePath + '/'+ baseFilename +extension;    var outputFile =fs.createWriteStream(filename);     // Done writing the file   // Move it to top level directory   // and create MD5 hash   outputFile.on('finish', function (){     console.log('file has been written');     // New name for the file    var newfilename = uploadpath +request.param('directoryname')+ '/' + baseFilename    + extension;      // Check if file exists at top level if it does delete it    //if (fs.ensureFileSync(newfilename)) {    fs.removeSync(newfilename);     //}     // Move the file    fs.move(filename, newfilename ,function (err) {      if (err) {       response.status(500).send(err);       return;      }      else {       // Delete the temporary directory      fs.removeSync(localFilePath);       varhash = crypto.createHash('md5'),        hashstream = fs.createReadStream(newfilename);        hashstream.on('data', function (data) {        hash.update(data)       });        hashstream.on('end', function (){        var md5results =hash.digest('hex');        // Send back a sucessful response with the file name       response.status(200).send('Sucessfully merged file ' + filename + ", "        + md5results.toUpperCase());        response.end();       });      }     });    });     // Loop through the file chunks and write them to the file   // files[index] retunrs the name of the file.   // we need to add put in the full path to the file   for (var index infiles) {     console.log(files[index]);     var data = fs.readFileSync(localFilePath +'/' +files[index]);     outputFile.write(data);     fs.removeSync(localFilePath + '/' + files[index]);    }    outputFile.end();   }  }) ;

// String padding left code taken from // http://www.lm-tech.it/Blog/post/2012/12/01/String-Padding-in-Javascript.aspx String.prototype.padLeft = function (paddingChar, length) {   var s = new String(this);   if ((this.length< length)&& (paddingChar.toString().length > 0)) {    for (var i = 0; i < (length - this.length) ; i++) {     s = paddingChar.toString().charAt(0).concat(s);    }   }   return s; } ;

<defaultDocument>  <files>   <add value="server.js" />  </files>  </defaultDocument>   <handlers>  <!-- indicates that the server.js file is a node.js application to be handled by the   iisnode module -->   <add name="iisnode" path="*.js" verb="*" modules="iisnode" />  </handlers>   <rewrite>  <rules>   <rule name="CelerFTJS">   <match url="/*" />   <action type="Rewrite" url="server.js" />   </rule>    <!-- Don't interfere with requests for node-inspector debugging -->    <rule name="NodeInspector" patternSyntax="ECMAScript" stopProcessing="true">   <match url="^server.js//debug[//]?" />   </rule>  </rules>  </rewrite>

// 使用跨域资源共享 // Taken from http://bannockburn.io/2013/09/cross-origin-resource-sharing-cors-with-a-node-js-express-js-and-sencha-touch-app/ var enableCORS = function(request,response, next){   response.header('Access-Control-Allow-Origin', '*');   response.header('Access-Control-Allow-Methods', 'GET,POST,OPTIONS');   response.header('Access-Control-Allow-Headers', 'Content-Type, Authorization, Content-      Length, X-Requested-With' ) ;    // 拦截OPTIONS方法 if ('OPTIONS' ==request.method){    response.send(204);   }   else {    next();   }  } ;   // 在表达式中使用跨域资源共享app. use ( enableCORS ) ;

// We are going to upload to a backend that supports parallel uploads. // Parallel uploads is supported by publishng the web site on different ports // The backen must implement CORS for this to work else if(workerdata.chunk!= null&& workerdata.paralleluploads ==true){   if (urlnumber >= 6) {    urlnumber = 0;   }    if (urlcount >= 6) {    urlcount = 0;   }    if (urlcount == 0) {    uploadurl = workerdata.currentlocation +webapiUrl + urlnumber;   }   else {    // Increment the port numbers, e.g 8000, 8001, 8002, 8003, 8004, 8005   uploadurl = workerdata.currentlocation.slice(0, -1) + urlcount +webapiUrl +    urlnumber;   }    upload(workerdata.chunk,workerdata.filename,workerdata.chunkCount, uploadurl,   workerdata.asyncstate);   urlcount++;   urlnumber++;  }