Exception in thread "main" java.net.BindException: Selenium is already running on port 4444. Or some other service is.

% java -jar selenium-server-standalone-2.45.0.jar -Dwebdriver.chrome.driver=chromedriver
13:28:31.897 INFO - Launching a standalone server
Setting system property webdriver.chrome.driver to chromedriver
13:28:31.980 INFO - Java: Oracle Corporation 24.55-b03
13:28:31.981 INFO - OS: Mac OS X 10.10.3 x86_64
13:28:32.005 INFO - v2.45.0, with Core v2.45.0. Built from revision 5017cb8
13:28:32.145 INFO - Default driver org.openqa.selenium.ie.InternetExplorerDriver registration is skipped: registration capabilities Capabilities [{platform=WINDOWS, ensureCleanSession=true, browserName=internet explorer, version=}] does not match with current platform: MAC
13:28:32.224 INFO - RemoteWebDriver instances should connect to: http://127.0.0.1:4444/wd/hub
13:28:32.225 INFO - Version Jetty/5.1.x
13:28:32.226 INFO - Started HttpContext[/selenium-server/driver,/selenium-server/driver]
13:28:32.227 INFO - Started HttpContext[/selenium-server,/selenium-server]
13:28:32.227 INFO - Started HttpContext[/,/]
13:28:32.282 INFO - Started org.openqa.jetty.jetty.servlet.ServletHandler@5523df1e
13:28:32.282 INFO - Started HttpContext[/wd,/wd]
13:28:32.288 WARN - Failed to start: SocketListener0@0.0.0.0:4444
Exception in thread "main" java.net.BindException: Selenium is already running on port 4444. Or some other service is.
    at org.openqa.selenium.server.SeleniumServer.start(SeleniumServer.java:491)
    at org.openqa.selenium.server.SeleniumServer.boot(SeleniumServer.java:300)
    at org.openqa.selenium.server.SeleniumServer.main(SeleniumServer.java:245)
    at org.openqa.grid.selenium.GridLauncher.main(GridLauncher.java:97)

Selenium サーバーが起動してしまっている場合

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

へアクセスしてokokと表示されれば、終了してくれます。