js base64 上传

<input type="file" id="fileInput" />
<button id="uploadButton">上传</button>

document.getElementById('uploadButton').addEventListener('click', function() {
    const fileInput = document.getElementById('fileInput');
    const file = fileInput.files[0];
    if (file) {
        const reader = new FileReader();
        reader.onload = function(event) {
            const base64String = event.target.result.split(',')[1]; // 去掉前缀
            uploadBase64(base64String);
        };
        reader.readAsDataURL(file);
    }
});

function uploadBase64(base64String) {
    fetch('/upload', {
        method: 'POST',
        headers: {
            'Content-Type': 'application/json'
        },
        body: JSON.stringify({ data: base64String })
    })
    .then(response => response.json())
    .then(data => {
        console.log('上传成功:', data);
    })
    .catch((error) => {
        console.error('上传失败:', error);
    });
}

const express = require('express');
const app = express();
const bodyParser = require('body-parser');
const fs = require('fs');

app.use(bodyParser.json({ limit: '50mb' }));

app.post('/upload', (req, res) => {
    const base64Data = req.body.data;
    const imgBuffer = Buffer.from(base64Data, 'base64');
    fs.writeFile('uploaded_image.png', imgBuffer, (err) => {
        if (err) {
            return res.status(500).send('文件保存失败');
        }
        res.send({ message: '文件上传成功' });
    });
});

app.listen(3000, () => {
    console.log('服务器运行在 http://localhost:3000');
});