java 大文件上传代码

以下是一个基本的Java大文件上传代码示例：

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;

public class FileUploader {

    private static final String UPLOAD_URL = "http://example.com/upload";
    private static final String FILE_PATH = "/path/to/file";

    public static void main(String[] args) {
        File file = new File(FILE_PATH);
        try {
            URL url = new URL(UPLOAD_URL);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setDoOutput(true);
            connection.setRequestMethod("POST");
            connection.setRequestProperty("Content-Type", "application/octet-stream");
            connection.setRequestProperty("Content-Length", String.valueOf(file.length()));
            OutputStream outputStream = connection.getOutputStream();
            FileInputStream inputStream = new FileInputStream(file);
            byte[] buffer = new byte[4096];
            int bytesRead = -1;
            while ((bytesRead = inputStream.read(buffer)) != -1) {
                outputStream.write(buffer, 0, bytesRead);
            }
            inputStream.close();
            outputStream.close();
            int responseCode = connection.getResponseCode();
            System.out.println("Response code: " + responseCode);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

该代码使用Java的URL和HttpURLConnection类将文件上传到指定的URL。它将文件读入字节数组中，然后将其写入输出流中。在发送请求后，代码将打印响应代码以指示上传是否成功。请注意，该代码仅适用于较小的文件（几百MB或更少）。对于大型文件，您可能需要使用分段上传或其他高级技术来确保稳定性和性能。