Generally speaking, there is no reliable way to determine that the connection has been re-established. A connection failure indicates the server has failed (either due to network problem, software or hardware failure, etc.). Depending on which transport being used (i.e. socket invoker), would be possible to re-connect once the server came back up, but only way to do this would be to continue to try sending invocations (if does not fail, then server back up).
Probably the best way to approach this is to use remoting detection (see http://labs.jboss.com/portal/jbossremoting/docs/guide/ch05.html#d0e853). This will allow you to receive a notification when the server comes back online and then know is safe to use that server again.