Node层模拟实现multipart表单的文件上传示例

/** * 上传文件 * @param files  经过formidable处理过的文件 * @param req  httpRequest对象 * @param postData 额外提交的数据 */function uploadFile(files, req, postData) { var boundaryKey = Math.random().toString(16); var endData = '/r/n----' + boundaryKey + '--'; var filesLength = 0, content; // 初始数据，把post过来的数据都携带上去 content = (function (obj) {  var rslt = [];  Object.keys(obj).forEach(function (key) {   arr = ['/r/n----' + boundaryKey + '/r/n'];   arr.push('Content-Disposition: form-data; name="' + key + '"/r/n/r/n');   arr.push(obj[key]);   rslt.push(arr.join(''));  });  return rslt.join(''); })(postData); // 组装数据 Object.keys(files).forEach(function (key) {  if (!files.hasOwnProperty(key)) {   delete files.key;   return;  }  content += '/r/n----' + boundaryKey + '/r/n' +   'Content-Type: application/octet-stream/r/n' +   'Content-Disposition: form-data; name="' + key + '"; ' +   'filename="' + files[key].name + '"; /r/n' +   'Content-Transfer-Encoding: binary/r/n/r/n';  files[key].contentBinary = new Buffer(content, 'utf-8');  filesLength += files[key].contentBinary.length + fs.statSync(files[key].path).size; }); req.setHeader('Content-Type', 'multipart/form-data; boundary=--' + boundaryKey); req.setHeader('Content-Length', filesLength + Buffer.byteLength(endData)); // 执行上传 var allFiles = Object.keys(files); var fileNum = allFiles.length; var uploadedCount = 0; allFiles.forEach(function (key) {  req.write(files[key].contentBinary);  var fileStream = fs.createReadStream(files[key].path, {bufferSize: 4 * 1024});  fileStream.on('end', function () {   // 上传成功一个文件之后，把临时文件删了   fs.unlink(files[key].path);   uploadedCount++;   if (uploadedCount == fileNum) {    // 如果已经是最后一个文件，那就正常结束    req.end(endData);   }  });  fileStream.pipe(req, {end: false}); });}

var result = [];response.on('data', function (chunk) { result.push(chunk);});// 处理responsevar _dealResponse = function (data) { var buffer = data; try {  data = data.toString('utf8');  data = data ? (JSON.parse(data) || data) : false; } catch (err) {  // 接口返回数据格式异常，解析失败  console.log(err); } self.res.writeHead(response.statusCode, 'OK', {  'content-type': 'text/plain; charset=utf-8',  'content-length': buffer.length }); self.res.write(buffer); self.res.end();};response.on('end', function () { result = Buffer.concat(result); // gzip 的数据，需要zlib解码 if (response.headers['content-encoding'] == 'gzip') {  zlib.gunzip(result, function (err, dezipped) {   var data = err ? new Buffer('{}') : dezipped;   _dealResponse(data);  }); } else {  _dealResponse(result); }});