问我试图写一个上传文件接口的node.js案列，结果得到了一个错误：？

提问于 2023-08-04 02:06:35

回答 1关注 0查看 215

得到这个错误：

TypeError [ERR_INVALID_ARG_TYPE]: The "data" argument must be of type string or an instance of Buffer, TypedArray, or DataView. Received undefined

这是我的html代码：

<!DOCTYPE html>
<html>

<head>
    <title>文件上传</title>
</head>

<body>
    <input type="file" id="fileInput">
    <button onclick="uploadFile()">上传</button>
    <script src="https://cdn.jsdelivr.net/npm/axios/dist/axios.min.js"></script>
    <script>
        function uploadFile() {
            const fileInput = document.getElementById('fileInput');
            const file = fileInput.files[0]; 
            const formData = new FormData();
            formData.append('file', file); 
            axios.post('http://localhost:8801/upload', 
            formData, {
                headers: {
                    'Content-Type': 'multipart/form-data'
                }
            }).then(response => {
                    console.log(response.data);
                })
                .catch(error => {
                    console.error(error);
                });
        }
    </script>
</body>

</html>

下面是node.js代码：

const cors = require("cors")
const express = require('express');
const multer = require('multer');
const path = require('path');
const fs = require('fs');
const { log } = require("console");
const app = express();
app.use(cors())
const upload = multer({ dest: 'uploads/' });
app.post('/upload', upload.single('file'), (req, res) => {
  const file = req.file;
  //获取原始文件名
  const originFile = file.originalname;
  console.log(originFile);
  //将原始文件名进行分割获取文件名的后缀
  const fileExt = originFile.split(".")[1];
  console.log(fileExt)
  //拼接新的文件名 用时间戳的方式
  const newFileNmae = Date.now() + "." + fileExt;
  console.log(newFileNmae)
  const filePath = path.join(__dirname, 'uploads', newFileNmae);
  // 检查路径是否存在，如果不存在则创建路径
  const directory = path.dirname(filePath);
  if (!fs.existsSync(directory)) {
    fs.mkdirSync(directory, { recursive: true });
  }  // 将上传的文件写入指定路径
  fs.writeFile(filePath, file.buffer, (err) => {
    if (err) {
      console.error(err);
      res.status(500).send('文件上传失败');
    } else {
      res.send('文件上传成功');
    }
  });
});
app.listen(8801, () => {
  console.log('服务端已启动，监听端口 8801');
});

我使用的node.js版本：v18.17.0

用了cors express multer path fs等模块

node.js