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;