Connect to FTP site with Apache commons net FTP client through Proxy

[Jon Mena]

Hello,

I am trying to run this simple code to connect to FTP site through a proxy.

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

public class MyTest {

public static void main(String[] args) {
String ftpHostName = "ftp.xxx.com";
int ftpPort = 21;
String ftpUserName = "myUserName";
String ftpPassword = "myPassword";

System.setProperty("socksProxyHost" ,"10.148.0.131");
System.setProperty("socksProxyPort", "1080");

FTPClient ftpClient = new FTPClient();

try {
System.out.println("connecting");
ftpClient.connect(ftpHostName, ftpPort);
System.out.println("connected");
System.out.println("loging in");
boolean successLogin = ftpClient.login(ftpUserName, ftpPassword);

if(successLogin)
System.out.println("success login");
else
System.out.println("fail login");
}
catch (Exception e) {
e.printStackTrace();
}
finally {
try {
System.out.println("loging out");
ftpClient.logout();
System.out.println("disconecting");
ftpClient.disconnect();
}
catch (Exception e) {
e.printStackTrace();
}
}
}
}

I am getting the following error:
C:\temp\ftp\test>java.exe -cp ./commons-net-ftp-2.0.jar;. MyTest connecting
java.net.SocketException: Malformed reply from SOCKS server
at java.net.SocksSocketImpl.readSocksReply(SocksSocketImpl.java:87)
at java.net.SocksSocketImpl.connectV4(SocksSocketImpl.java:265)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:437)
at java.net.Socket.connect(Socket.java:519)
at org.apache.commons.net.SocketClient.connect(SocketClient.java:176)
at MyTest.main(MyTest.java:23)
loging out
java.lang.NullPointerException
at org.apache.commons.net.ftp.FTP.sendCommand(FTP.java:471<ftp://FTP.java:471>)
at org.apache.commons.net.ftp.FTP.sendCommand(FTP.java:534<ftp://FTP.java:534>)
at org.apache.commons.net.ftp.FTP.sendCommand(FTP.java:583<ftp://FTP.java:583>)
at org.apache.commons.net.ftp.FTP.quit(FTP.java:794<ftp://FTP.java:794>)
at org.apache.commons.net.ftp.FTPClient.logout(FTPClient.java:697)
at MyTest.main(MyTest.java:39)

I am able to do this using a different FTP client library, ftp4j-1.5.1, using the following code:

import it.sauronsoftware.ftp4j.FTPClient;
import it.sauronsoftware.ftp4j.connectors.SOCKS4Connector;

public class MyTestFtp4J {

public static void main(String[] args) {
String ftpHostName = "ftp.xxx.com";
int ftpPort = 21;
String ftpUserName = "myUserName";
String ftpPassword = "myPassword";

FTPClient ftpClient = new FTPClient();
ftpClient.setConnector(new SOCKS4Connector("10.148.0.131", 1080));

try {
System.out.println("connecting");
ftpClient.connect(ftpHostName, ftpPort);
System.out.println("connected");
System.out.println("loging in");
ftpClient.login(ftpUserName, ftpPassword);
System.out.println("success login");
}
catch (Exception e) {
e.printStackTrace();
}
finally {
try {
System.out.println("disconecting");
ftpClient.disconnect(true);
}
catch (Exception e) {
e.printStackTrace();
}
}
}
}

So I know the proxy settings are correct.
The java version I used to compile and run my apps is 1.6.0_06 Does anyone can help figure out what is wrong when I use the Apache commons net FTP client?

Thank you

Jon

[Martijn Verburg]

Hi Jon and welcome to Javaranch!

Is that the recommended way to set a proxy using commons-net? Also, download the source code and have a look as to why it could be throwing the NPE at that line. Oh and are you using version 2.0?

[Jon Mena]

Based on what I read on the FAQ for the library, this is the way to connect to FTP through proxy. The version is 2.0. I was not able to make it work and used a different library eventually, ftp4j, which worked fine for my need.

Thank you for your reply

Jon

[Karthik Ng]

Hi,
I'm facing the same issue( Exception - Malformed reply from SOCKS server), can any one suggest solution?

Thanks,
Karthik

[Dhamodharan Ramalingam]

I am also facing this kind of issue, any help is greatly appreciated.

Thanks,
Dhamu