Why can't I log onto my Bukkit Server?

Today, I created a bukkit server on minecraft so that my friends and I can play on it. I logged onto the server the first time with no problems. I exited out of the server.command as well as the game and when I opened it back up "Perhaps a server is already running on that port?" showed up when the server.command was loading, and when I tried to log into the server on my minecraft application "Failed to Connect to Server, Timed Out." showed up on my screen. I have not the slightest bit of explanation for this, and how do I get back on my server to play with my friends. ( I'm on a mac if that helps)

Oh! Okay so what you do is first, you go into the mac's task manager, find a process called Javaw and end it, this should reset all Java things and your server should run again!

Also not to advertise or anything, but would you mind coming on mine sometime? 37.187.134.194:25928

Happens to me when I reset the server too much. But I usually just restart my computer and it's fine.

You just need to restart your computer and next time you wanna close the server just write( stop ) in the server command