java.net.SocketTimeoutException:读取FTPClient.listFiles超时

Question

我正试图使用Apache Commons Net FTPSClient列出FTP服务器上CurrentWorkingDirectory中的文件，代码如下。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&使用了私有数据连接(下面的代码有效(client.execPBSZ(0(；client.execPROT("P"(；