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社区首页 >问答首页 >将POST请求的数据流存储在GridFS、express、mongoDB、node.js中

将POST请求的数据流存储在GridFS、express、mongoDB、node.js中
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Stack Overflow用户
提问于 2014-01-01 00:08:39
回答 4查看 16.9K关注 0票数 18

我正在尝试弄清楚如何将图像直接发布到GridFS,而不必先将其作为临时文件存储在服务器上的任何位置。

我正在使用Postman (chrome ext.)为了发布一个文件,我设法将这篇文章存储为一个文件,使用:

req.pipe(fs.createWriteStream('./test.png'));

当从服务器上的文件创建readStream时,我还可以直接从readStream存储到GridFS。(参见代码)

我有以下文件,saveFromReq.js监听POST,基本上只是将其传递给savePic.js

saveFromReq.js:

var express = require('express');
var app = express();
var savePic = require('./savePic');
var fs = require('fs');
var GridStore = require('mongodb').GridStore;
var pic = './square.png';
var picID;



//When the following

 //var pic = fs.createReadStream('./square.png', {autoClose: true});

//is not commented out, and 'req' is replaced with 'pic' in the savePic function,
//the file square.png is stored correctly to GridFS

app.post('/picture', function(req, res){

    savePic(req, function(id){});
    res.writeHead(200, {'Content-Type': 'text' });
    res.end("Sucsess!\n");

});

app.listen(process.env.PORT || 3413);

savePic.js:

var savePic = function(req, callback){


var Db = require('mongodb').Db,
    MongoClient = require('mongodb').MongoClient,
    Server = require('mongodb').Server,
    ReplSetServers = require('mongodb').ReplSetServers,
    ObjectID = require('mongodb').ObjectID,
    Binary = require('mongodb').Binary,
    GridStore = require('mongodb').GridStore,
    Grid = require('mongodb').Grid,
    Code = require('mongodb').Code,
    BSON = require('mongodb').pure().BSON,
    assert = require('assert');
    fs = require('fs');

    //When the following 

      //req.pipe(fs.createWriteStream('./test.png'));

    //is not commented out, the correct image is stored to test.png, and 
    //the sequence after req.on("data"... starts
    //(That sequence does not start at all when this is commented out..)

var fileId = new ObjectID();
var db = new Db('testDB', new Server('localhost', 27017));
// Establish connection to db
db.open(function(err, db) {


  var gridStore = new GridStore(db, 'test', 'w');

  //open 
  gridStore.open(function(err, gridStore) {
    console.log("opened");


    req.on("data", function (data) {
        console.log("data recieved");
            gridStore.write(data, function (err, gridStore) {
                if (err) {
                    console.log("error writing file");
                }
            });
        });
     req.on("end", function () {
            gridStore.close(function (err, gridStore) {
                if (!err) {
                    console.log("The file has been stored to database.");
                    db.close();
                }
            });
        });
           req.pipe(gridStore);


      });




});
callback(fileId);
};
module.exports = savePic;

任何帮助都将不胜感激!

EN

回答 4

Stack Overflow用户

回答已采纳

发布于 2014-01-01 01:41:09

gridfs-stream让这一切变得非常简单:

// `gfs` is a gridfs-stream instance
app.post('/picture', function(req, res) {
  req.pipe(gfs.createWriteStream({
    filename: 'test'
  }));
  res.send("Success!");
});
票数 18
EN

Stack Overflow用户

发布于 2015-12-12 19:43:33

虽然@robertklep的答案是正确的,但我想对他的答案补充一些东西。这段代码展示了如何发回存储文件的元数据。

app.post('/picture', function(req, res) {
  req.pipe(gfs.createWriteStream({
    filename: 'test'
  }).on('close', function(savedFile){
    console.log('file saved', savedFile);
    return res.json({file: savedFile});
  }));
})  
票数 2
EN

Stack Overflow用户

发布于 2017-01-07 23:57:58

在nodejs.This中使用gridfs在mongodb中插入to文件的完整代码运行良好`

var mongoose=require("mongoose");
var gridfsstream=require("gridfs-stream");
var fs=require("fs");
mongoose.connect("mongodb://localhost:27017/testimage");
var conn=mongoose.connection;
gridfsstream.mongo=mongoose.mongo;
conn.once("open",function()
{
    console.log("database connected successfully");
    var gfs=gridfsstream(conn.db);
    var writestream=gfs.createWriteStream({
        filename:"danger.txt"
    });
    fs.createReadStream("sivakasi.txt").pipe(writestream);
    writestream.on("close",function(file)
    {
        console.log(file.filename +"stored successfully into mongodb using gridfs");
    });
    writestream.on("error",function(file)
    {
        console.log(file.filename +"not stored into mongodb using gridfs");
    });
});
conn.on("error",function()
{
    console.log("database not connected try again!!!");
});

`

票数 0
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页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接:

https://stackoverflow.com/questions/20860005

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