java.net.SocketTimeoutException：在 FTPClient.listFiles 读取超时

Question

我正在尝试使用 Apache Commons Net FTPSClient 和下面的代码在 FTP 服务器上列出 CurrentWorkingDirectory 中的文件。 我能够使用 WinSCP 成功连接和下载文件。

        FTPSClient client = new FTPSClient(true);
        client.setDefaultTimeout(defaultTimeout);
        client.setConnectTimeout(connectTimeout);
        client.setDataTimeout(dataTimeout);
        
        client.connect(server, 990);
        int replyCode = client.getReplyCode();
        if (!FTPReply.isPositiveCompletion(replyCode)){
            LOG.error("Unable to connect to server. Error Text=" + client.getReplyString());
        }
        
        if (localActive) {
            setLocalActiveMode();
        } else {
            setLocalPassiveMode();
        }
        
        boolean status = client.login(user, password);
        if (!status) {
            replyCode = client.getReplyCode();
            LOG.error("Login failed. Error Text=" + client.getReplyString());
        }
        setBinaryMode(binaryMode);
        client.changeWorkingDirectory(path);
        
        FTPFile[] files = client.listFiles();
        for (FTPFile file : files) {

引发的异常：

java.net.SocketTimeoutException: Read timed out
   at java.net.SocketInputStream.socketRead0(Native Method)
   at java.net.SocketInputStream.socketRead(SocketInputStream.java:116)
   at java.net.SocketInputStream.read(SocketInputStream.java:171)
   at java.net.SocketInputStream.read(SocketInputStream.java:141)
   at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:284)
   at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:326)
   at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:178)
   at java.io.InputStreamReader.read(InputStreamReader.java:184)
   at java.io.BufferedReader.fill(BufferedReader.java:161)
   at java.io.BufferedReader.readLine(BufferedReader.java:324)
   at java.io.BufferedReader.readLine(BufferedReader.java:389)
   at org.apache.commons.net.ftp.FTPFileEntryParserImpl.readNextEntry(FTPFileEntryParserImpl.java:53)
   at org.apache.commons.net.ftp.FTPListParseEngine.readStream(FTPListParseEngine.java:128)
   at org.apache.commons.net.ftp.FTPListParseEngine.readServerList(FTPListParseEngine.java:104)
   at org.apache.commons.net.ftp.FTPClient.initiateListParsing(FTPClient.java:3302)
   at org.apache.commons.net.ftp.FTPClient.initiateListParsing(FTPClient.java:3271)
   at org.apache.commons.net.ftp.FTPClient.listFiles(FTPClient.java:2930)
   at org.apache.commons.net.ftp.FTPClient.listFiles(FTPClient.java:2977)

WinSCP 会话日志

WinSCP 会话日志续..

WinSCP 会话日志续..

Apache Commons Net 日志文件

Answer 1

我将保护缓冲区大小设置为 0 并使用了私有数据连接（下面的代码并有效） client.execPBSZ(0); client.execPROT("P");