Selenium: Invalid “already running” error when starting server

Question

I am trying to get the Selenium server up and running. However, when I type:

java -jar selenium-server-standalone-2.0b3.jar

I get an Exception

Answer 1

This worked for me:

http://localhost:4444/selenium-server/driver/?cmd=shutDownSeleniumServer

If selenium server is already running on port 4444 then it will shut down the server and says OKOK if selenium is not running on this port 4444 then by hitting above url will give you "Unable to connect"