Java8中使用lambda不爲null時才過濾值

基於使用Java 8的一些參數來過濾此列表。可是若是參數是null，則拋出NullPointerException。如何過濾掉空值

List<String> carsFiltered = Optional.ofNullable(cars)
            .orElseGet(Collections::emptyList)
            .stream()
            .filter(Objects::nonNull) //filtering car object that are null
            .map(Car::getName) //now it's a stream of Strings
            .filter(Objects::nonNull) //filtering null in Strings
            .filter(name -> name.startsWith("M"))
            .collect(Collectors.toList()); //back to List of Strings