Sikuli and Selenium over JAVA

Hey people / developers,

In java, can i use selenium in combination with sikuli?
This would be highly appreciated since many are eager to do this!

may be like this:

selenium = new DefaultSelenium("localhost", 4444, "*firefox", "http://www.google.com/");
 selenium.start();
 selenium.open("http://www.google.com/");
 selenium.waitForPageToLoad("30000");
        selenium.windowMaximize();

 selenium.windowFocus();
 sikuli.click("image/google.png", 0);

Prsently this is not working (Exception in thread "main" java.lang.NullPointerException) is there any way that this can work?