On eclipse, when you execute a Maven RUN with: tomcat7:run on your project, if you change some classes, you don't need to re-run your application in order to check the changes. I think is "hot-code swap" or something like that.
Is it possible to do that on IntelliJ?
yeah you have 4 options:
First press Ctrl + F10
you will see:
The second is the answer. More info here:
http://www.jetbrains.com/idea/webhelp/updating-applications-running-on-application-servers.html
EDIT 2018: IntelliJ IDEA 2017.3.3