node.js - 错误 ReferenceError : ObjectID is not defined

Question

我想用 GridJS 上传图片。我正在使用 https://www.npmjs.org/package/gridfs-stream为了这。它给我 error ReferenceError: ObjectID is not defined。

我是初学者，所以不知道发生了什么。

如何解决这个错误？

var Grid = require('gridfs-stream');
    var conn = mongoose.createConnection('localhost', 'Test', 27017);
    var gfs = Grid(conn.db, mongoose);

    var fileId = new ObjectID(uniqId);
    var fileType = req.header('X-File-Type');
    var fileName = req.header('X-File-Name');
    var uniqId = req.param('uniqId', '112211112111');

    console.log('upload start');
    // streaming to gridfs
    var writestream = gfs.createWriteStream(fileId, [{ "content_type": fileType, "metadata": { "fileName": fileName, "uploaded_at": (new Date()).toString() } }]);
    fs.createReadStream('/some/path').pipe(writestream);

    // streaming from gridfs
    var readstream = gfs.createReadStream(fileId, [{ "content_type": fileType, "metadata": { "fileName": fileName, "uploaded_at": (new Date()).toString() } }]);

    //error handling, e.g. file does not exist
    readstream.on('error', function (err) {
        console.log('An error occurred!', err);
        throw err;
    });

    readstream.pipe(response);
    console.log('upload done');

Answer 1

ObjectID 不是全局变量，它由 mongoose 定义(参见 documentation ):

var fileId = mongoose.Types.ObjectId();