使用gridfs-stream将文件直接存储在mongodb中

Question

I need save some files like: images,video,pdf... into mongodb, so i use gridfs-stream and express.js

var file = req.files.file; 
req.pipe(gfs.createWriteStream({
    filename:file.originalname,
    mode:"w",
    chunkSize:1024*4,
    content_type:file.mimetype,
    root:"fs"
})
res.send(200);

for testing i use postman and set an POST request this way:

 POST /fs/upload HTTP/1.1
 Host: localhost:5000
 Cache-Control: no-cache

 ----WebKitFormBoundaryE19zNvXGzXaLvS5C
 Content-Disposition: form-data; name="file"; filename="epic.png"
 Content-Type: image/png


  ----WebKitFormBoundaryE19zNvXGzXaLvS5C

the problem is that this way just store the data of the file:

{
    "_id" : ObjectId("54d14ec5b102fe401519a3c1"),
    "filename" : "epic.png",
    "contentType" : "image/png",
    "length" : 0,
    "chunkSize" : 4096,
    "uploadDate" : ISODate("2015-02-03T22:42:14.730Z"),
    "aliases" : null,
    "metadata" : null,
    "md5" : "993fb9ce262a96a81c79a38106147e95"
}

but not the content i mean de binary data for it, into mongodb is store for it the propety length is equal to 0, bacause has not any chunks in fs.chucks.

Answer 1

Reading in blogs found the answer to streaming data directly at database with express.js,gridfs-stream.js and multer middleware that way:

var multer = require('multer');

app.post('/fs/upload', multer({
    upload: null,// take uploading process 

    onFileUploadStart: function (file) {
        //set upload with WritableStream        
        this.upload = gfs.createWriteStream({
            filename: file.originalname,
            mode: "w",
            chunkSize: 1024*4,
            content_type: file.mimetype,
            root: "fs"
        });
     },

     onFileUploadData: function (file, data) {
        //put the chucks into db 
        this.upload.write(data);
     },

     onFileUploadComplete: function (file) {
        //end process 
        this.upload.on('drain', function () {
            this.upload.end();
        });
     }
}), function (req, res) {
   res.sendStatus(200);
});

For testing this:

app.route('/fs/download/:file').get(function (req, res) {
   var readstream = gfs.createReadStream({_id: req.params.file});
   readstream.pipe(res);
});