使用Express在Nodejs中发送和接收文件

$ npm install express multer

const express = require('express');
const multer = require('multer');
const app = express();

const storage = multer.diskStorage({
  destination: function (req, file, cb) {
    cb(null, 'uploads/'); // 指定文件保存的目录
  },
  filename: function (req, file, cb) {
    cb(null, file.originalname); // 指定保存的文件名
  }
});

const upload = multer({ storage: storage });

app.post('/upload', upload.single('file'), function (req, res, next) {
  // 文件上传成功后的处理逻辑
  res.send('文件上传成功');
});

app.get('/download/:filename', function (req, res, next) {
  const filename = req.params.filename;
  const filePath = __dirname + '/uploads/' + filename;

  res.download(filePath, function (err) {
    if (err) {
      // 文件下载失败的处理逻辑
      res.status(404).send('文件不存在');
    }
  });
});

app.listen(3000, function () {
  console.log('应用程序已启动，监听端口3000');
});