FTP client not working behind proxy

[Mathias Nilsson]

Hi!

I am using the jakarta net commons library for ftp client. It works fine when I'm not behind a proxy server. I found this information on the net library

Since the Net project uses java.net.Socket under the covers, you have to set
up the Socket settings. If the proxy you are using is a SOCKS4 or SOCKS5
proxy, you can set the following System Properties:

System.getProperties().put( "socksProxyPort", "1080");
System.getProperties().put( "socksProxyHost" ,"proxy.host.address");

When I check the proxy settings for the computer( Mac os x ) we are only using FTP proxy, HTTP proxy and HTTPS proxy. The Socks proxy is not set. How can I still use the jakarta net library? Is there a way to use the ftpProxyPort and ftpProxyHost in the library?

// Mathias

[Ulf Dittmer]

Have you tried the other settings mentioned in this discussion?
[ August 15, 2006: Message edited by: Ulf Dittmer ]

[Mathias Nilsson]

Yes! I've tried all of them.

http proxy , ftp proxy and socks proxy.

But our proxy server only has ftp and http. Is there any workaround?

[Mathias Nilsson]

If I use the java.net.Proxy class in java 1.5 then there is no Proxy.Type.FTP. Can I use Proxy.Type.HTTP and connect to an FTP proxy?

If I can't then is there anyway to use the apache commons FTPClient and connect thru a FTP proxy. No HTTP and Socks just FTP?

[Paul Clapham]

I use Commons FTP Client to connect via an FTP proxy. But the FTP proxy in question is an open-source Java product; I have to connect to it rather than the target FTP server, and pass it the address of the server in a different way than if I were connecting directly. It's not just a matter of changing a system property. However your FTP proxy may work differently.

[Mathias Nilsson]

I don't think setting any of the proxy properties will get me anywere.

I looked into the FTP client class in the jakarta net library and saw that the socket was created from the ServerSocket. Can a proxy be set in the serversocket and/or the socket class without using the java 1.5?

A lot of programmers out there must be in the same situation and solve this. There are not much information when I google around.

[Paul Clapham]

My proxy server didn't even claim to support FTP, so I got this FTP proxy software and installed it where it could connect to the outside world. Works just fine, except occasionally connections to it hang up. But then that happens for other FTP servers, too. But as I said, you do need to modify the connection code in your software to connect to the proxy instead of the target server.

[Mathias Nilsson]

I have tried connecting thru the java 1.5 Proxy class. Here is my code

InetSocketAddress proxyAddress = new InetSocketAddress( "our.ftp.proxy" , 1021 );
Proxy proxy = new Proxy( Proxy.Type.HTTP , proxyAddress );
 
InetSocketAddress ftpSite = new InetSocketAddress( "ftpSite" , 21 );
Socket socket = new Socket( proxy );
 
socket.connect( ftpSite );
 

I can't create the socket because an IllegalArgumentException is thrown! I don't get it. When i check the settings in the network it only uses Ftp proxy and http proxy no socks proxy.

The ftp proxy port is the same as I use in my java program but I can't connect. How can I connect to a ftp site on port 21 going thru port 1021 on our proxy?

[Mathias Nilsson]

I have still not solved this. All other FTP programs installed on my mac can by typing in the adress and port solv the problem. How come they work and not the jakarta FTP client?

[Aalok Pandit]

Hi Mathias

Not sure if this helps you, but I was facing a similar problem.

The error I was getting was :
"Host attempting data connection is not same as server" or something like that.

I have posted the solution in my topic
FTP connection to a Proxy

hope this solves your problem