Grails services are abstractions used for implementing business logic (as well as connecting to backing services/DBs, etc.) outside of a controller. So in a typical controller y
One way of achieving this is by using ServletContext-
ApplicationContext ctx = (ApplicationContext)ServletContextHolder.
getServletContext().getAttribute(GrailsApplicationAttributes.APPLICATION_CONTEXT)
statisticsService = (StatisticsService ) ctx.getBean("statisticsService ")
see this blog - http://www.grailsbrains.com/availing-grails-goodies-in-srcjava-or-srcgroovy/