可以尝试使用FTPClient进行文件传输，以下为示例代码：

import org.apache.commons.net.ftp.FTP;
import org.apache.commons.net.ftp.FTPClient;

import java.io.FileInputStream;
import java.io.IOException;

public class FtpUtil {
    private static FTPClient ftp = new FTPClient();
    private static String username = "username";
    private static String password = "password";
    private static String ftpHost = "ftp.example.com";
    private static int ftpPort = 21;

    /**
     * 上传文件至FTP服务器
     *
     * @param localFilePath  本地文件路径
     * @param remoteFilePath 远程文件路径
     * @throws IOException
     */
    public static void uploadFile(String localFilePath, String remoteFilePath) throws IOException {
        FileInputStream localFileInputStream = new FileInputStream(localFilePath);
        ftp.setControlEncoding("UTF-8");
        ftp.connect(ftpHost, ftpPort);
        ftp.login(username, password);
        // 设置成主动模式，否则由于路由器防火墙等原因会上传失败
        ftp.enterLocalPassiveMode();  
        ftp.setFileType(FTP.BINARY_FILE_TYPE);
        boolean isSuccess = ftp.storeFile(remoteFilePath, localFileInputStream);
        if (isSuccess) {
            System.out.println("文件上传成功！本地路径：" + localFilePath + "，远程路径：" + remoteFilePath);
        } else {
            System.out.println("文件上传失败！本地路径：" + localFilePath + "，远程路径：" + remoteFilePath);
        }
        localFileInputStream.close();
        ftp.logout();
    }
}