You can do this with several libraries. My favorite is the ssh library inside MindTerm package,
http://linuxmafia.com/pub/java/ISNetworks-MindTerm-1.2.1-SCP3.tar.gz
You can open a tunneled connection like this,
SSHSocketFactory fact = new SSHSocketFactory(sshHost, sshPort, new SSHPasswordAuthenticator(sshUser, sshPassword));
sock = fact.createSocket(host, port);