上传后，使用ExpressJS将文件存储在Mongo的GridFS中 [英] Store file in Mongo's GridFS with ExpressJS after upload

问题描述

我已经开始使用expressJS构建REST api.我是Node的新手，请耐心等待.我希望能够让用户使用/upload路由中的帖子直接将文件上传到Mongo的GridFS.

I have started building a REST api using expressJS. I am new to node so please bear with me. I want to be able to let users upload a file directly to Mongo's GridFS using a post to the /upload route.

据我在expressJS文档中所了解的，req.files.image对象在上传后的路径中可用，其中还包括路径和文件名属性.但是，如何准确读取图像数据并将其存储到GridFS中呢?

From what I understand in expressJS documentation the req.files.image object is available in the route after uploading, which also includes a path and filename attribute. But how can I exactly read the image data and store it into GridFS?

我已经研究了 gridfs-stream ，但我无法将两端结合在一起.我是否首先需要读取文件，然后将该数据用于writestream管道?还是可以只使用express中的文件对象，然后使用这些属性来构造一个writestream?任何指针将不胜感激！

I have looked into gridfs-stream but I can't tie ends together. Do I first need to read the file and then use that data for the writestream pipe? Or can I just use the file object from express and use those attributes to construct a writestream? Any pointers would be appreciated!

推荐答案

这是一个简单的演示:

Here's a simple demo:

var express = require('express');
var fs      = require('fs');
var mongo   = require('mongodb');
var Grid    = require('gridfs-stream');
var db      = new mongo.Db('test', new mongo.Server("127.0.0.1", 27017), { safe : false });

db.open(function (err) {
  if (err) {
    throw err;
  }
  var gfs = Grid(db, mongo);
  var app = express();

  app.use(express.bodyParser());
  app.post('/upload', function(req, res) {
    var tempfile    = req.files.filename.path;
    var origname    = req.files.filename.name;
    var writestream = gfs.createWriteStream({ filename: origname });
    // open a stream to the temporary file created by Express...
    fs.createReadStream(tempfile)
      .on('end', function() {
        res.send('OK');
      })
      .on('error', function() {
        res.send('ERR');
      })
      // and pipe it to gfs
      .pipe(writestream);
  });

  app.get('/download', function(req, res) {
    // TODO: set proper mime type + filename, handle errors, etc...
    gfs
      // create a read stream from gfs...
      .createReadStream({ filename: req.param('filename') })
      // and pipe it to Express' response
      .pipe(res);
  });

  app.listen(3012);
});

我使用 httpie 上传文件:

http --form post localhost:3012/upload filename@~/Desktop/test.png

您可以检查数据库是否上传了文件

You can check your database if the file is uploaded:

$ mongofiles list -d test
connected to: 127.0.0.1
test.png    5520

您也可以再次下载:

http --download get localhost:3012/download?filename=test.png

这篇关于上传后，使用ExpressJS将文件存储在Mongo的GridFS中的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！