如何通过http包上传多张图片到mysql flutter

import 'dart:io';
import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;
import 'package:image_picker/image_picker.dart';

class ImageUploadPage extends StatefulWidget {
  @override
  _ImageUploadPageState createState() => _ImageUploadPageState();
}

class _ImageUploadPageState extends State<ImageUploadPage> {
  List<File> _images = [];

  Future<void> _selectImages() async {
    final pickedFiles = await ImagePicker().pickMultiImage();
    if (pickedFiles != null) {
      setState(() {
        _images = pickedFiles.map((file) => File(file.path)).toList();
      });
    }
  }

  Future<void> _uploadImages() async {
    final url = 'YOUR_API_ENDPOINT'; // 替换为后端API接口的URL
    final request = http.MultipartRequest('POST', Uri.parse(url));

    for (var image in _images) {
      final file = await http.MultipartFile.fromPath('images', image.path);
      request.files.add(file);
    }

    final response = await request.send();
    if (response.statusCode == 200) {
      print('Images uploaded successfully!');
    } else {
      print('Failed to upload images. Error code: ${response.statusCode}');
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Image Upload'),
      ),
      body: Column(
        children: [
          ElevatedButton(
            onPressed: _selectImages,
            child: Text('Select Images'),
          ),
          ElevatedButton(
            onPressed: _uploadImages,
            child: Text('Upload Images'),
          ),
          Expanded(
            child: ListView.builder(
              itemCount: _images.length,
              itemBuilder: (context, index) {
                return Image.file(_images[index]);
              },
            ),
          ),
        ],
      ),
    );
  }
}

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

const app = express();

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

const connection = mysql.createConnection({
  host: 'YOUR_MYSQL_HOST',
  user: 'YOUR_MYSQL_USER',
  password: 'YOUR_MYSQL_PASSWORD',
  database: 'YOUR_MYSQL_DATABASE',
});

app.post('/upload', upload.array('images'), (req, res) => {
  const files = req.files;

  for (const file of files) {
    // 将文件插入到MySQL数据库中
    connection.query('INSERT INTO images (file_path) VALUES (?)', [file.path], (error, results, fields) => {
      if (error) {
        console.error('Failed to insert image into database:', error);
      } else {
        console.log('Image inserted successfully!');
      }
    });
  }

  res.sendStatus(200);
});

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