js请求json文件上传

// HTML部分
<input type="file" id="jsonFileInput" accept=".json" />

// JavaScript部分
document.getElementById('jsonFileInput').addEventListener('change', function(event) {
    const file = event.target.files[0];
    if (file) {
        const formData = new FormData();
        formData.append('file', file);

        fetch('/upload', {
            method: 'POST',
            body: formData
        })
        .then(response => response.json())
        .then(data => {
            console.log('Success:', data);
        })
        .catch((error) => {
            console.error('Error:', error);
        });
    }
});

const express = require('express');
const multer = require('multer');
const app = express();
const upload = multer({ dest: 'uploads/' });

app.post('/upload', upload.single('file'), (req, res) => {
    const file = req.file;
    if (!file) {
        return res.status(400).send('No file uploaded.');
    }

    const fs = require('fs');
    const path = require('path');
    const filePath = path.join(__dirname, file.path);

    fs.readFile(filePath, 'utf8', (err, data) => {
        if (err) {
            return res.status(500).send('Error reading file.');
        }

        try {
            const jsonData = JSON.parse(data);
            console.log('Parsed JSON:', jsonData);
            res.status(200).send('File uploaded and parsed successfully.');
        } catch (parseError) {
            res.status(400).send('Invalid JSON file.');
        }
    });
});

app.listen(3000, () => {
    console.log('Server is running on port 3000');
});