I have an application running in apache-tomcat-6.0.20. Is it possible to redirect the following url "http://localhost:8080/someapp/login.jsp" to another url "http://localhost:8090/someapp/login.jsp" since 8080 port is already in use. My requirement is if anyone try to access the url with 8080 port it should automatically redirect to url with 8090 port.
You say there's another unrelated server already listening at port 8080? Then that server is going to get all the requests sent to port 8080. That's how it works.
I suppose you could try playing around with your network routers to do this sort of port mapping, but then the unrelated server wouldn't get any requests. In which case you might just as well shut it down and have your server run at port 8080, which is what you wanted anyway. So just shut down the other server and run yours at port 8080.