Every Element is identified by it's "metaclass". Element metaclass is mapped into java interface (for example com.nomagic.uml2.ext.magicdraw.classes.mdkernel.Class). Use com.nomagic.magicdraw.uml.BaseElement.getClassType() to retrieve the element metaclass.Use com.nomagic.magicdraw.uml.ClassTypes for managing the metaclasses - collecting all available, collecting derived and etc.