How can I find out which ports are open?

Hi all -
I apologise if this has been covered already, but I did a quick search and couldn't find an answer.
I'm trying to find a way of finding out what ports/sockets are open on a machine at any point in time - so I'm after some method to return a list of open ports.
Ideally I was hoping there'd be a method in java.net that returned an enumeration of open ServerSockets that I could traverse, but couldn't find anything.

Has anyone done this or have any ideas? There's plenty of examples showing how to open a ServerSocket and then connect to that known socket - but what if you don't know the port number?
Cheers-
Den

hi Den,
all the info regarding active ports on Windows platforms is given by netstat command. if u r looking to see this info thru some java program then u'll have to use Runtime class to execute this in command prompt.
Regards,
Nitin

Thanks for the tip - I didn't think of running a host machine tool to find it out. :roll:
I was just hoping to do it all in the code and not have to call an external tool, but I guess I can invoke netstat. How I'll parse the output from it, I have no idea.

Thanks again,
Den