If it takes you 5s to start up your server, that's a lot of time you've added to each development iteration. Make a change, restart the server, wait 5s, see if it works/check debug output.
Now-a-days, starting a Tomcat or TomEE JVM in debug mode with Eclipse gives you the ability to hot swap probably 95% of your changes. It doesn't supporting adding completely new functions or changing declared fields. JRebel does support this though.
As a matter of fact, if you're in a stack frame and you pause the execution pointer with a breakpoint, you can completely change the code of the function and the JVM will discard the current stack frame and then restart the functional call. Essentially, you can rewrite your code, while it's executing, without losing your stack.
Make a change, restart the server, wait 5s, see if it works/check debug output.
Most of us aren't waiting 5 seconds before checking output. We just refresh the browser.
If even that's too much, there's JRebel which does full hot reloading of pretty much every piece of code you change.
I'm a ruby guy btw..
And don't get me started on the Azure Compute Emulator.