final Map singleAppMap = CollectionUtilsisNotEmptylist HashMapliststreamfiltersingle - StringUtilsequalsserialNumber String HashMap singlegetWBSNOfindFirstorElsenull

Map singleAppMap = null; if (CollectionUtils.isNotEmpty(list)) { singleAppMap = list.stream() .filter(single -> StringUtils.equals(serialNumber, (String)((HashMap)single).get("WBSNO"))) .findFirst() .orElse(null); }