package com.iluwatar.featuretoggle.user; import java.util.ArrayList; import java.util.List; /** * Created by joseph on 26/01/16. */ public class UserGroup { private static List freeGroup = new ArrayList<>(); private static List paidGroup = new ArrayList<>(); public static void addUserToFreeGroup(final User user){ if(paidGroup.contains(user)){ throw new IllegalArgumentException("User all ready member of paid group."); }else{ if(!freeGroup.contains(user)){ freeGroup.add(user); } } } public static void addUserToPaidGroup(final User user){ if(freeGroup.contains(user)){ throw new IllegalArgumentException("User all ready member of free group."); }else{ if(!paidGroup.contains(user)){ paidGroup.add(user); } } } public static boolean isPaid(User user) { return paidGroup.contains(user); } }