or nba -> sports
or nike -> sports/shoe
or sadkljasd -> unknown

Map<String, String> mapping = new HashMap<String, String>();
mapping.put("nba", "sports");

String type = mapping.get("nba");

System.out.println(type);   // Will give you `sports`

Map<String, ArrayList<String>> mapping =
                             new HashMap<String, ArrayList<String>>();