如何将gridStore替换为gridFSBucket？

Question

我有这个错误信息。

(node:11976) DeprecationWarning: GridStore is deprecated, and will be removed in a future version. Please use GridFSBucket instead

有时我无法查看图片，我想就是因为这样，由于文档不完善，我不知道如何将我的代码切换到GridFSBucket，就是这样。

conn.once("open", () => {
  // Init stream
  gfs = Grid(conn.db, mongoose.mongo);
  //gfs = new mongoose.mongo.GridFSBucket(conn.db);
  gfs.collection("user_images");
});


var storageImage = new GridFsStorage({
  url: dbURI,
  options: { useNewUrlParser: true, useUnifiedTopology: true },
  file: (req, file) => {
    return new Promise((resolve, reject) => {
      crypto.randomBytes(16, (err, buf) => {
        if (err) {
          return reject(err);
        }
        const filename = buf.toString("hex") + path.extname(file.originalname);
        const fileInfo = {
          filename: filename,
          bucketName: "user_images"
        };
        resolve(fileInfo);
      });
    });
  }
});
const uploadImage = multer({ storage: storageImage });

    const uploadImage = multer({ storage: storageImage });
router.get("/image/:filename", (req, res) => {
  gfs.files.findOne({ filename: req.params.filename }, (err, file) => {
    if (!file || file.length === 0) {
      return res.status(404).json({
        err: "No file exists"
      });
    }

    if (file.contentType === "image/jpeg" || file.contentType === "image/png") {
      const readstream = gfs.createReadStream(file.filename);
      //const readstream = gridFSBucket.openUploadStream(file.filename);
      readstream.pipe(res);
    } else {
      res.status(404).json({
        err: "Not an image"
      });
    }
  });
});

我真的很感激你的帮助，我需要改变什么才能使它与GridFsBucket一起工作，先谢谢你了!

Answer 1

我按照这个 教程 来创建这个食谱。教程是真棒，它解释了所有的步骤很好。完整的代码示例可以找到 此处.

Html表格示例。

<form action="http://localhost:4000/upload" method="post" enctype="multipart/form-data">
      <input type="file"  name='image' />
      <button type="submit" >Submit</button>
</form>

Controller配方上传图片到mongodb。

const path = require('path');
const crypto = require('crypto');
const mongoose = require('mongoose');
const multer = require('multer');
const GridFsStorage = require('multer-gridfs-storage');
const Grid = require('gridfs-stream');

const mongodbURL="mongodb+srv://<user>:<pass>@cluster.mongodb.net/<databaseName>"
const connection = mongoose.createConnection(mongoURI);

// Init gfs
let gfs;
const image_bucket_name = "user_images"

connection.once('open', () => {
    // Init stream
    gfs = Grid(connection.db, mongoose.mongo);
    gfs.collection(image_bucket_name);
})

// Create storage engine
const storage = new GridFsStorage({
    url: mongoURI,
    file: (req, file) => {
        return new Promise((resolve, reject) => {
            crypto.randomBytes(16, (error, buffer) => {
                if (error) {
                    return reject(error);
                }
                const filename = buffer.toString('hex') + path.extname(file.originalname);
                const fileinfo = {
                    filename: filename,
                    bucketName: image_bucket_name
                };
                resolve(fileinfo);
            })
        });
    }
});

const upload = multer({ storage });
app.post('/upload', upload.single('image'), async (req, res) => {
    console.log("uploaded image: "+req.file.
});