import grails.converters.*

        class CourseController {
        def index = { redirect(action:list,params:params) }
        // the delete, save and update actions only accept POST requests
            static allowedMethods = [delete:'POST', save:'POST', update:'POST']

            def list = {
                params.max = Math.min( params.max ? params.max.toInteger() : 10,  100)
                //[ courseInstanceList: Course.list( params ) , courseInstanceTotal: Course.count() ]
            	def courses = Course.list( params )
            	// return a bunch of json data with metadata.
            	def json = [
            		 totalCount: courses.size,
            		 results: courses
            	]

            	render json as JSON


            }
    //other methods.... that i didn't touch
}

unable to resolve class org.codehaus.groovy.grails.co
mmons.metaclass.ExpandoMetaClass
 @ line 4, column 1.
   import org.codehaus.groovy.grails.commons.metaclass.ExpandoMetaClass