帮我设计一套java大文件上传代码

当你需要上传大文件时，最好的方式是通过分片上传。这意味着将大文件分成小块，逐个上传，这样即使在网络不稳定的情况下，也可以保证上传的可靠性。以下是一个简单的Java代码示例，用于实现大文件分片上传：

import java.io.*;
import java.net.*;
import java.util.UUID;

public class UploadLargeFile {

    private final static int CHUNK_SIZE = 1024 * 1024; // 每个分片的大小

    public static void main(String[] args) {
        String fileToUpload = "/path/to/large/file"; // 待上传的大文件路径
        String uploadURL = "http://example.com/upload"; // 上传接口URL
        String boundary = UUID.randomUUID().toString(); // 分界符

        try {
            File file = new File(fileToUpload);
            long fileSize = file.length();
            int chunks = (int) Math.ceil((double) fileSize / CHUNK_SIZE);

            HttpURLConnection httpConn = (HttpURLConnection) new URL(uploadURL).openConnection();
            httpConn.setDoOutput(true);
            httpConn.setRequestMethod("POST");
            httpConn.setRequestProperty("Content-Type", "multipart/form-data; boundary=" + boundary);

            OutputStream outputStream = httpConn.getOutputStream();
            PrintWriter writer = new PrintWriter(new OutputStreamWriter(outputStream, "UTF-8"), true);

            // 循环上传每个分片
            for (int i = 0; i < chunks; i++) {
                writer.append("--").append(boundary).append("\r\n");
                writer.append("Content-Disposition: form-data; name=\"file\"; filename=\"").append(file.getName()).append(".").append(i).append("\"\r\n");
                writer.append("Content-Type: ").append(URLConnection.guessContentTypeFromName(file.getName())).append("\r\n");
                writer.append("\r\n");

                FileInputStream inputStream = new FileInputStream(file);
                inputStream.skip(i * CHUNK_SIZE);
                byte[] buffer = new byte[CHUNK_SIZE];
                int bytesRead = 0;
                while ((bytesRead = inputStream.read(buffer)) != -1) {
                    outputStream.write(buffer, 0, bytesRead);
                }
                outputStream.flush();
                inputStream.close();

                writer.append("\r\n");
            }

            // 结束分界符
            writer.append("--").append(boundary).append("--").append("\r\n");
            writer.flush();
            writer.close();

            // 获取HTTP响应码
            int responseCode = httpConn.getResponseCode();
            if (responseCode == HttpURLConnection.HTTP_OK) {
                System.out.println("文件上传成功！");
            } else {
                System.out.println("文件上传失败。HTTP响应码：" + responseCode);
            }
            httpConn.disconnect();
        } catch (IOException ex) {
            ex.printStackTrace();
        }
    }
}

你需要将`fileToUpload`变量替换为你要上传的大文件的本地路径，将`uploadURL`变量替换为你的上传接口URL。执行以上代码后，程序会自动将大文件分成小块逐个上传，上传成功后会在控制台输出相应信息。注意，以上代码仅供参考，具体实现应根据实际情况进行调整。