Express + MongoDB 实现文件上传

使用 `multer` 中间件来处理文件上传，同时将文件的元数据存储到 MongoDB 中。

一、安装依赖

npm install multer

二、核心代码

// 定义文件模型const fileSchema = new mongoose.Schema({originalname: String,mimetype: String,size: Number,path: String,});const File = mongoose.model("File", fileSchema);// 配置 multerconst storage = multer.diskStorage({destination: function (req, file, cb) {cb(null, "uploads/");},filename: function (req, file, cb) {cb(null, Date.now() + path.extname(file.originalname));},});const upload = multer({ storage: storage });// 创建上传目录const fs = require("fs");if (!fs.existsSync("uploads")) {fs.mkdirSync("uploads");}// 处理文件上传app.post("/upload", upload.single("file"), async (req, res) => {try {const { originalname, mimetype, size, path } = req.file;const newFile = new File({originalname,mimetype,size,path,});await newFile.save();res.status(200).json({ message: "文件上传成功", file: newFile });} catch (error) {res.status(500).json({ message: "文件上传失败", error: error.message });}});