java hijack socket possible?

Question

I suddenly find myself wondering this question, is it possible in java to hijack a socket?

say a server is listening on port 5000, would it be possible to write a java p

Answer 1

Or maybe you want to capture the traffic and inject your packets in communication ? If so, then try jpcap

Answer 2

Network sockets are managed by the operating system, and the OS will not let you bind to a socket that is already in use. So yes, you would need to do some trickery on the network driver level.

Answer 3

Sounds like you are being naughty. As Thilo said, you can't typically hijack a port. You could proxy for the port, so have clients connect to port 5001, and your program listens on 5001, then forwards to 5000. You could also do the same at the host level - replace host X with host y. Host y runs your program on port 5000 and forwards to host X on port 5000.