List<DocumentAuthorization> authorization; final Map<Long, List<DocumentAuthorization>> authorizationTableMap = authorization.stream() .collect(Collectors.groupingBy(DocumentAuthorization::getTableId));
List<DocumentAuthorization> authorization; final Map<Long, List<DocumentAuthorization>> authorizationTableMap = authorization.stream() .collect(Collectors.groupingBy(DocumentAuthorization::getTableId));