lambda-aventures.java

// Catch valores nulos
disabledUsersOnLDAP.stream()
    .map(User::getUsername)
    .map(usersRepository::findEnabledByUsername)
    .filter(Objects::nonNull) // <-- Util
    .forEach(userEntity -> userEntity.setEnabled(false));

// Obtener el número máximo de una lista
Integer lastPaysheetPaymentId = lst.stream()
    .mapToInt(VwRecalculatedRent::getPaysheetPaymentDetailId)
    .max()
    .orElseThrow(NoSuchElementException::new);

// Sumar valores de una lista
Double promisesAmount = accountPaymentsList.stream()
    .mapToDouble(AccountPayments::getAmount)
    .filter(Objects::nonNull)
    .sum();

// Guardar una propiedad de una lista en otra lista
List<Integer> lstCurrent = paymentPlanListOfCurrentMonth.stream()
    .map(VwPaymentPlanToChart::getCount)
    .collect(Collectors.toList());

// Unir dos listas sin repetir valores iguales
ArrayList<String> listOne = new ArrayList<>(Arrays.asList("a", "b", "c", "d", "e"));
ArrayList<String> listTwo = new ArrayList<>(Arrays.asList("a", "b", "c", "f", "g"));

List<String> combinedList = Stream.concat(
    listOne.stream(),
    listTwo.stream())
    .distinct()
    .collect(Collectors.toList());