├── README.md
├── package-lock.json
└── node_modules
    └── ...
├── package.json
├── public
│   └── index.html
└── src
    ├── App.css
    ├── App.js
    ├── components
    │   └── UploadFiles.js
    ├── http-common.js
    ├── index.js
    └── services
        └── UploadFilesService.js

├── README.md
├── package.json
├── pnpm-lock.yaml
└── node_modules
    └── ...
└── src
    ├── config
    │   └── db.js
    ├── controllers
    │   └── flileUploadController.js
    ├── middleware
    │   └── upload.js
    ├── routes
    │   └── index.js
    └── server.js

npx create-react-app react-multiple-files-upload

pnpm install
pnpm install axios

npm install bootstrap

import React from "react";
import "./App.css";
import "bootstrap/dist/css/bootstrap.min.css";
function App() {
  return (
    <div className="container">
      ...
    </div>
  );
}
export default App;

import axios from "axios";
export default axios.create({
  baseURL: "http://localhost:8080",
  headers: {
    "Content-type": "application/json"
  }
});

import http from "../http-common";
const upload = (file, onUploadProgress) => {
  let formData = new FormData();
  formData.append("file", file);
  return http.post("/upload", formData, {
    headers: {
      "Content-Type": "multipart/form-data",
    },
    onUploadProgress,
  });
};
const getFiles = () => {
  return http.get("/files");
};
const FileUploadService = {
  upload,
  getFiles,
};
export default FileUploadService;

import React, { useState, useEffect, useRef } from "react";
import UploadService from "../services/UploadFilesService";
const UploadFiles = () => {
  return (
    
  );
};
export default UploadFiles;

const UploadFiles = () => {
    const [selectedFiles, setSelectedFiles] = useState(undefined);
    const [progressInfos, setProgressInfos] = useState({ val: [] });
    const [message, setMessage] = useState([]);
    const [fileInfos, setFileInfos] = useState([]);
    const progressInfosRef = useRef(null)
}

const UploadFiles = () => {
  ...
  const selectFiles = (event) => {
    setSelectedFiles(event.target.files);
    setProgressInfos({ val: [] });
  };
  ...
}

const UploadFiles = () => {
  ...
  const uploadFiles = () => {
    const files = Array.from(selectedFiles);
    let _progressInfos = files.map(file => ({ percentage: 0, fileName: file.name }));
    progressInfosRef.current = {
      val: _progressInfos,
    }
    const uploadPromises = files.map((file, i) => upload(i, file));
    Promise.all(uploadPromises)
      .then(() => UploadService.getFiles())
      .then((files) => {
        setFileInfos(files.data);
      });
    setMessage([]);
  };
  ...
}

const upload = (idx, file) => {
    let _progressInfos = [...progressInfosRef.current.val];
    return UploadService.upload(file, (event) => {
        _progressInfos[idx].percentage = Math.round(
            (100 * event.loaded) / event.total
        );
        setProgressInfos({ val: _progressInfos });
    })
        .then(() => {
            setMessage((prevMessage) => ([
                ...prevMessage,
                "文件上傳成功: " + file.name,
            ]));
        })
        .catch(() => {
            _progressInfos[idx].percentage = 0;
            setProgressInfos({ val: _progressInfos });
            setMessage((prevMessage) => ([
                ...prevMessage,
                "不能上傳文件: " + file.name,
            ]));
        });
};

const UploadFiles = () => {
  ...
  useEffect(() => {
    UploadService.getFiles().then((response) => {
      setFileInfos(response.data);
    });
  }, []);
  ...
}

const UploadFiles = () => {
  ...
  return (
    <div>
      {progressInfos && progressInfos.val.length > 0 &&
        progressInfos.val.map((progressInfo, index) => (
          <div className="mb-2" key={index}>
            <span>{progressInfo.fileName}</span>
            <div className="progress">
              <div
                className="progress-bar progress-bar-info"
                role="progressbar"
                aria-valuenow={progressInfo.percentage}
                aria-valuemin="0"
                aria-valuemax="100"
                style={{ width: progressInfo.percentage + "%" }}
              >
                {progressInfo.percentage}%
              </div>
            </div>
          </div>
        ))}
      <div className="row my-3">
        <div className="col-8">
          <label className="btn btn-default p-0">
            <input type="file" multiple onChange={selectFiles} />
          </label>
        </div>
        <div className="col-4">
          <button
            className="btn btn-success btn-sm"
            disabled={!selectedFiles}
            onClick={uploadFiles}
          >
            上傳
          </button>
        </div>
      </div>
      {message.length > 0 && (
        <div className="alert alert-secondary" role="alert">
          <ul>
            {message.map((item, i) => {
              return <li key={i}>{item}</li>;
            })}
          </ul>
        </div>
      )}
      <div className="card">
        <div className="card-header">List of Files</div>
        <ul className="list-group list-group-flush">
          {fileInfos &&
            fileInfos.map((file, index) => (
              <li className="list-group-item" key={index}>
                <a href={file.url}>{file.name}</a>
              </li>
            ))}
        </ul>
      </div>
    </div>
  );
};

const UploadFiles = () => {
  ...
}
export default UploadFiles;

import React from "react";
import "./App.css";
import "bootstrap/dist/css/bootstrap.min.css";
import UploadFiles from "./components/UploadFiles.js"

function App() {
  return (
    <div className="container">
      <h4> 使用 React 搭建文件上傳 Demo</h4>
      <div className="content">
        <UploadFiles />
      </div>
    </div>
  );
}

export default App;

PORT=8081

mkdir nodejs-mongodb-upload-files
cd nodejs-mongodb-upload-files

npm init --yes

npm install express cors multer multer-gridfs-storage mongodb

{
  "name": "nodejs-mongodb-upload-files",
  "version": "1.0.0",
  "description": "Node.js upload multiple files to MongoDB",
  "main": "src/server.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [
    "node",
    "upload",
    "multiple",
    "files",
    "mongodb"
  ],
  "license": "ISC",
  "dependencies": {
    "cors": "^2.8.5",
    "express": "^4.17.1",
    "mongodb": "^4.1.3",
    "multer": "^1.4.3",
    "multer-gridfs-storage": "^5.0.2"
  }
}

module.exports = {
  url: "mongodb://localhost:27017/",
  database: "files_db",
  filesBucket: "photos",
};

const util = require("util");
const multer = require("multer");
const { GridFsStorage } = require("multer-gridfs-storage");
const dbConfig = require("../config/db");

var storage = new GridFsStorage({
  url: dbConfig.url + dbConfig.database,
  options: { useNewUrlParser: true, useUnifiedTopology: true },
  file: (req, file) => {
    const match = ["image/png", "image/jpeg", "image/gif"];

    if (match.indexOf(file.mimetype) === -1) {
      const filename = `${Date.now()}-zhijianqiu-${file.originalname}`;
      return filename;
    }
    return {
      bucketName: dbConfig.filesBucket,
      filename: `${Date.now()}-zhijianqiu-${file.originalname}`
    };
  }
});
const maxSize = 2 * 1024 * 1024;
var uploadFiles = multer({ storage: storage, limits: { fileSize: maxSize } }).single("file");
var uploadFilesMiddleware = util.promisify(uploadFiles);
module.exports = uploadFilesMiddleware;

const upload = require("../middleware/upload");
const dbConfig = require("../config/db");
const MongoClient = require("mongodb").MongoClient;
const GridFSBucket = require("mongodb").GridFSBucket;

const url = dbConfig.url; 

const baseUrl = "http://localhost:8080/files/";

const mongoClient = new MongoClient(url);

const uploadFiles = async (req, res) => {
  try {
    await upload(req, res);
    if (req.file == undefined)  {
      return res.status(400).send({ message: "請選擇要上傳的文件" });
    }
    return res.status(200).send({
      message: "文件上傳成功" + req.file.originalname,
    });
  } catch (error) {
    console.log(error);
     if (error.code == "LIMIT_FILE_SIZE") {
      return res.status(500).send({
        message: "文件大小不能超過 2MB",
      });
    }
    return res.status(500).send({
      message: `無法上傳文件:, ${error}`
    });
  }
};

const getListFiles = async (req, res) => {
  try {
    await mongoClient.connect();

    const database = mongoClient.db(dbConfig.database); 
    const files = database.collection(dbConfig.filesBucket + ".files");
    let fileInfos = [];

    if ((await files.estimatedDocumentCount()) === 0) {
        fileInfos = []
    }

    let cursor = files.find({})
    await cursor.forEach((doc) => {
      fileInfos.push({
        name: doc.filename,
        url: baseUrl + doc.filename,
      });
    });

    return res.status(200).send(fileInfos);
  } catch (error) {
    return res.status(500).send({
      message: error.message,
    });
  }
};

const download = async (req, res) => {
  try {
    await mongoClient.connect();
    const database = mongoClient.db(dbConfig.database);
    const bucket = new GridFSBucket(database, {
      bucketName: dbConfig.filesBucket,
    });

    let downloadStream = bucket.openDownloadStreamByName(req.params.name);
    downloadStream.on("data", function (data) {
      return res.status(200).write(data);
    });

    downloadStream.on("error", function (err) {
      return res.status(404).send({ message: "無法獲取文件" });
    });

    downloadStream.on("end", () => {
      return res.end();
    });
  } catch (error) {
    return res.status(500).send({
      message: error.message,
    });
  }
};

module.exports = {
  uploadFiles,
  getListFiles,
  download,
};

const express = require("express");
const router = express.Router();
const uploadController = require("../controllers/flileUploadController");
let routes = app => {
  router.post("/upload", uploadController.uploadFiles);
  router.get("/files", uploadController.getListFiles);
  router.get("/files/:name", uploadController.download);
  return app.use("/", router);
};
module.exports = routes;

const cors = require("cors");
const express = require("express");
const app = express();
global.__basedir = __dirname;
var corsOptions = {
  origin: "http://localhost:8081"
};
app.use(cors(corsOptions));
const initRoutes = require("./routes");
app.use(express.urlencoded({ extended: true }));
initRoutes(app);
let port = 8080;
app.listen(port, () => {
  console.log(`Running at localhost:${port}`);
});

Running at localhost:8080

node src/server.js

pnpm start