我编写了一个独立的程序来将文件上传到 FTP 服务器。代码运行良好,但我在 FTP 上找不到文件。这是代码
import java.io.FileInputStream;
import java.io.IOException;
import java.net.SocketException;
import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.net.ftp.FTPReply;
public class FTPDemo {
    public static void main(String[] args) {
        FTPClient ftp = new FTPClient();
        int reply;
        try {
            ftp.connect("ip address");
            ftp.login("username","password");
            reply = ftp.getReplyCode();
            if(FTPReply.isPositiveCompletion(reply)){
                System.out.println("Connected Success");
            }else {
                System.out.println("Connection Failed");
                ftp.disconnect();
            }
            FileInputStream fis = null;
            String filename = "demo.txt";
            fis = new FileInputStream("C:\\demo.txt");
            System.out.println("Is file stored: "+ftp.storeFile(filename,fis));
            fis.close();
            ftp.disconnect();
        } catch (SocketException ex) {
            ex.printStackTrace();
        } catch (IOException ex) {
            ex.printStackTrace();
        }
    }
}
是否存储文件返回 false。可能是什么问题呢 ?