用Java写一个上传文件的功能函数

好的，以下是使用 Java 上传文件的示例代码：

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Base64;
import java.util.Map;

public class FileUploader {
    private static final String LINE_FEED = "\r\n";

    /**
     * 使用 POST 方法上传文件
     *
     * @param requestURL 请求的 URL
     * @param fileFormName 文件表单字段的名称
     * @param file 文件对象
     * @param authHeader 认证的头信息（可选）
     * @param otherParams 其他参数（可选）
     * @return 服务器的响应信息
     * @throws Exception
     */
    public static String uploadFile(String requestURL, String fileFormName, File file,
                                    String authHeader, Map<String, String> otherParams) throws Exception {
        HttpURLConnection connection = null;
        OutputStream outputStream = null;
        BufferedReader reader = null;

        try {
            // 创建连接
            URL url = new URL(requestURL);
            connection = (HttpURLConnection) url.openConnection();
            connection.setRequestMethod("POST");
            connection.setDoInput(true);
            connection.setDoOutput(true);
            connection.setUseCaches(false);
            connection.setRequestProperty("Connection", "Keep-Alive");
            connection.setRequestProperty("Content-Type", "multipart/form-data;boundary=" + getBoundary());

            // 设置认证的头信息
            if (authHeader != null && !authHeader.isEmpty()) {
                connection.setRequestProperty("Authorization", authHeader);
            }

            // 获取输出流
            outputStream = connection.getOutputStream();

            // 写入文件数据
            outputStream.write(("--" + getBoundary() + LINE_FEED).getBytes());
            outputStream.write(("Content-Disposition: form-data; name=\"" + fileFormName + "\"; filename=\""
                    + file.getName() + "\"" + LINE_FEED).getBytes());
            outputStream.write(("Content-Type: " + URLConnection.guessContentTypeFromName(file.getName()) + LINE_FEED)
                    .getBytes());
            outputStream.write(("Content-Transfer-Encoding: binary" + LINE_FEED).getBytes());
            outputStream.write(LINE_FEED.getBytes());

            FileInputStream inputStream =