通过nodejs将文件上传到mongodb

//fileserver.js 


 var http = require("http"), 

     url = require("url"), 

     mongo = require('mongodb'), 

     path = require("path"), 

     ObjectID = require('mongodb').ObjectID, 

     Grid = require('gridfs-stream'), 

     gridform = require('gridform'), 

     fs = require("fs"), 

     GridStore = require('mongodb').GridStore; 



 function FileServer(db) { 

     if (!(this instanceof FileServer)) return new FileServer(db); 

     this.db = db; 

 } 


 FileServer.prototype.start = function start(listenport) { 

     var me = this; 

     me.db.open(function(err) { 

         if (err) { 

             console.log(err); 

             return; 

         } 

         app.listen(listenport, "127.0.0.1"); 

         console.log("Server running at http://127.0.0.1:" + listenport); 


     }); 


     var app = http.createServer(function(req, res) { 


         var pathname = url.parse(req.url).pathname; 

         //upload 

         if (pathname.indexOf('/upload') >= 0 && 'POST' == req.method) { 

             gridform.db = me.db; 

             gridform.mongo = mongo; 

             var outObj; 

             var form = gridform(); 

             form.parse(req, function(err, fields, files) { 

                 if (err) { 

                     outObj = { 

                         "status": 0, 

                         "message": err 

                     } 


                 } else { 

                     for (var obj in files) { 

                         outObj = { 

                             status: 1, 

                             data: { 

                                 name: files[obj].name, 

                                 id: files[obj].id.toString(), 

                                 url: 'http://' + req.headers.host + '/id/' + files[obj].id.toString() 

                             } 

                         }; 

                     } 


                 } 

                 console.log('received upload..'); 

                 me.responMsg(res, 200, JSON.stringify(outObj)); 

             }); 


         } else if (pathname != '/') { //download/// 

             var filename, fileId, delPos, idPos, strId; 


             delPos = pathname.indexOf('/delete/'); 

             idPos = pathname.indexOf('/id/'); 

             //通过ID匹配文件 

             if (idPos >= 0) { 

                 strId = pathname.substr(idPos + 4, pathname.length - idPos + 1); 

                 filename = { 

                     _id: strId 

                 }; 

                 fileId = ObjectID(strId); 

             } else { 

                 filename = pathname.replace('/', ''); 

             } 

             console.log('get file:' + filename); 

             //优先查找磁盘中的文件 

             var realPath = "files" + pathname; 



             path.exists(realPath, function(exists) { 

                 if (exists) { 

                     fs.readFile(realPath, "binary", function(err, file) { 

                         if (err) { 

                             me.responMsg(res, 500, err); 

                         } else { 

                             var ext = path.extname(realPath); 

                             ext = ext ? ext.slice(1) : 'unknown'; 

                             var contentType = mime[ext] || "text/plain"; 

                             res.writeHead(200, { 

                                 'Content-Type': contentType 

                             }); 

                             res.write(file, "binary"); 

                             res.end(); 

                         } 

                     }); 

                 } else { 

                     // Verify that the file exists 

                     me.exist(me.db, fileId || filename, function(err, result, item) { 

                         if (!result) { 

                             me.responMsg(res, 404, "文件不存在"); 

                             return; 

                         } 

                         if (delPos >= 0) { 

                             GridStore.unlink(me.db, item._id, function(err) { 

                                 me.responMsg(res, 200, 'success') 

                             }); 

                         } else { 

                             var gfs = Grid(me.db, mongo); 

                             var readstream = gfs.createReadStream(filename); 

                             var ext = item.filename.split('.'); 

                             ext = ext ? ext[ext.length-1] : 'unknown'; 

                             var contentType = mime[ext] || "text/plain"; 


                             res.setHeader("Content-Type", contentType); 

                             readstream.pipe(res); 

                         } 

                     }); 

                 } 

             }); 


         } else { 

             res.setHeader("Content-Type", "text/html"); 

             res.end( 

                 '<form method="post" action="/upload" enctype="multipart/form-data">' + '<input type="file" name="text">' + '<input type="submit" value="upload">' + '</form>'); 

         } 


          

     }); 

 } 


 FileServer.prototype.responMsg = function responMsg(response, status, msg) { 

     response.writeHead(status, { 

         'Content-Type': 'text/plain;charset=utf-8' 

     }); 


     response.end(msg); 

 } 


 //覆盖了驱动里原始的exist方法，将找到的item也返回来 

 FileServer.prototype.exist = function exist(db, fileIdObject, rootCollection, callback) { 

     var args = Array.prototype.slice.call(arguments, 2); 

     callback = args.pop(); 

     rootCollection = args.length ? args.shift() : null; 


     // Fetch collection 

     var rootCollectionFinal = rootCollection != null ? rootCollection : GridStore.DEFAULT_ROOT_COLLECTION; 

     db.collection(rootCollectionFinal + ".files", function(err, collection) { 

         // Build query 

         var query = (typeof fileIdObject == 'string' || Object.prototype.toString.call(fileIdObject) == '[object RegExp]') ? { 

             'filename': fileIdObject 

         } : { 

             '_id': fileIdObject 

         }; // Attempt to locate file 

         collection.find(query, function(err, cursor) { 

             cursor.nextObject(function(err, item) { 

                 callback(null, item == null ? false : true, item); 

             }); 

         }); 

     }); 

 }; 


 var mime = { 


     "css": "text/css", 

     "gif": "image/gif", 

     "html": "text/html", 

     "ico": "image/x-icon", 

     "jpeg": "image/jpeg", 

     "jpg": "image/jpeg", 

     "js": "text/javascript", 

     "json": "application/json", 

     "pdf": "application/pdf", 

     "png": "image/png", 

     "svg": "image/svg+xml", 

     "swf": "application/x-shockwave-flash", 

     "tiff": "image/tiff", 

     "txt": "text/plain", 

     "wav": "audio/x-wav", 

     "wma": "audio/x-ms-wma", 

     "wmv": "video/x-ms-wmv", 

     "xml": "text/xml", 

     "doc": "application/msword", 

     "docx": "application/vnd.openxmlformats-officedocument.wordprocessingml.document", 

     "xls": "application/vnd.ms-excel", 

     "xlsx": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet" 


 }; 


 module.exports = exports = FileServer;