private String[] validateUIRules(SportsActivityVoCollection voSportColl) { if(voSportColl.equals(null)) return null; for(SportsActivityVo voSportsAct: voSportColl) { if(voSportsAct.getSelect() == null && voSportsAct.getComments() != null && !voSportsAct.getComments().equals("")) return new String[]{"Select is mandatory if Comments field is populated"}; } return null; }