小编sd2*_*018的帖子

我正在使用 Java Apache Commons Net 库从 FTP 服务器下载文件。作为起点，我试图重用来自https://www.codejava.net/java-se/networking/ftp/java-ftp-file-upload-tutorial-and-example 的代码。通常，代码执行时没有问题/异常，但是对于一个特定的 FTP 服务器 ( ftp://ftp.nasdaqtrader.com/symboldirectory/nasdaqlisted.txt ) 我收到以下错误：

org.apache.commons.net.MalformedServerReplyException：截断的服务器回复：'220'

我的代码如下：

String server = "ftp.nasdaqtrader.com";
int port = 21;
String user = "anonymous";
String pass = "pw";

FTPClient ftpClient = new FTPClient();
try {

    ftpClient.connect(server, port);
    ftpClient.login(user, pass);
    ftpClient.enterLocalPassiveMode();
    ftpClient.setFileType(FTP.BINARY_FILE_TYPE);

    // APPROACH #1: using retrieveFile(String, OutputStream)
    String remoteFile1 = "/symboldirectory/nasdaqlisted.txt";
    File downloadFile1 = new File("C:\\filedirectory\\nasdaqlisted.txt");
    OutputStream outputStream1 =
        new BufferedOutputStream(new FileOutputStream(downloadFile1));
    boolean success = ftpClient.retrieveFile(remoteFile1, outputStream1);
    outputStream1.close();

    if (success) {
        System.out.println("File #1 …