希望这可以帮助！
exports.getFileById = function(req, res){var role = req.session.user.role;var conn = mongoose.connection;var gfs = Grid(conn.db, mongoose.mongo);gfs.findOne({ _id: req.params.ID, root: 'resume' }, function (err, file) { if (err) { return res.status(400).send(err); } else if (!file) { return res.status(404).send('Error on the database looking for the file.'); } res.set('Content-Type', file.contentType); res.set('Content-Disposition', 'attachment; filename="' + file.filename + '"'); var readstream = gfs.createReadStream({ _id: req.params.ID, root: 'resume' }); readstream.on("error", function(err) { res.end(); }); readstream.pipe(res); });};
