Multer

Question

我在将图像文件上传到我的服务器时遇到问题，我在 YouTube 上观看了一些关于 multer 的教程，我做了与教程中完全相同的事情，但出于某种原因，我收到了一个错误：("无法读取属性 'buffer' of undefined"), req.file 也是未定义的。我用谷歌搜索了这个错误，发现有些人有同样的问题，我试着像他们一样解决它，但它对我不起作用。

组件数据应用程序

newPostByUser(token, formData) {
    return (async () =>
      await call(`${this.url}/lost`, {
        method: "POST",
        headers: {
          Authorization: `Bearer ${token}`,
          "Content-Type": "multipart/form-data",
        },
        body: formData,
        timeout: this.timeout,
      }))();
  },

组件图像解析

const path = require("path");
const multer = require("multer");
const storage = multer.memoryStorage();
const limits = { fileSize: 2000000 };
const upload = multer({
  storage,
  limits,
  fileFilter(req, file, cb) {
    var filetypes = /jpeg|jpg|png|gif/;
    const mimetype = filetypes.test(file.mimetype);
    const extname = filetypes.test(
      path.extname(file.originalname).toLocaleLowerCase()
    );
    if (mimetype && extname) {
      return cb(null, true);
    }
    cb(
      "Error: File upload only supports the following filetypes - " + filetypes
    );
  },
}).single("image");

function imageParse(req, res, next) {
  upload(req, res, function (err) {
    if (err) {
      return res.status(422).json({ error: err.message });
    }
    next();
  });
}

module.exports = imageParse;

组件路线

require("dotenv").config();
const express = require("express");
const logic = require("../logic");
const auth = require("./auth");
const imageParse = require("../utils/imageParse");
const literals = require("../i18n/literals");

const router = express.Router();

const { research_newPost_messageConfirm } = literals;

router.post("/lost", auth, imageParse, (req, res) => {
  console.log(req.buffer);
  const {
    file: { buffer },
    body: { userId, category, name, age, city, description, lang },
  } = req;
(async () => {
    try {
      const user = await logic.newResearch(
        buffer,
        userId,
        category,
        name,
        age,
        city,
        description,
        lang
      );
      res.status(201).json({ message: research_newPost_messageConfirm[lang] });
    } catch ({ message }) {
      res.status(400).json({ error: message });
    }
  })();
});

module.exports = router;

组件逻辑api

const streamifier = require("streamifier");
const cloudinary = require("cloudinary").v2;
const { Research } = require("../models");
const {
  CLOUDINARY_API_KEY,
  CLOUDINARY_SECRET_KEY,
  CLOUDINARY_NAME,
} = require("../utils/config");
const { logic_newPost_messageError} = require("../i18n/literals");

const logic = {
newResearch(buffer, userId, category, name, age, city, description, lang) {
    try {
      return (async () => {
        cloudinary.config({
          cloud_name: CLOUDINARY_NAME,
          api_key: CLOUDINARY_API_KEY,
          api_secret: CLOUDINARY_SECRET_KEY,
        });

        const image = await new Promise((resolve, reject) => {
          const uploadStream = cloudinary.uploader.upload_stream(
            (err, image) => {
              if (err) throw new LogicError("Image could not be uploaded");
              resolve(image);
            }
          );
          streamifier.createReadStream(buffer).pipe(uploadStream);
        });
        const newPost = await Research.create({
          owner: userId,
          category,
          name,
          age,
          city,
          description,
          image: image.secure_url,
        });

        if (!newPost) throw new Error(`${logic_newPost_messageError[lang]}`);
        console.log("api", newPost);
        return newPost;
      })();
    } catch (error) {
      console.log(error);
    }
  },
};

module.exports = logic;

Answer 1

不是req.buffer

是req.file.buffer

Answer 2

您需要使用 memoryStorage，它允许您将文件作为 Buffer 对象存储在内存中。

制作类似的东西：

import multer, { memoryStorage } from 'multer';

const upload = multer({
  storage: memoryStorage(),
  dest: './tmp'
});

categoriesRoutes.post(
  '/import',
  upload.single('file'),
  (req, res) => {
    console.log(req.file.buffer)
  }
);

Multer - 无法读取未定义的属性 'buffer'

Multer - Cannot read property 'buffer' of undefined

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Multer - 无法读取未定义的 属性 'buffer'

Multer - Cannot read property 'buffer' of undefined

javascript

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multer

cloudinary

Multer - 无法读取未定义的属性 'buffer'