Java: avoid checking for null in nested classes (Deep Null checking)

Question

Imagine I have a class Family. It contains a List of Person. Each (class) Person contains a (class) Address. Each (class) Address contains a (class) PostalCode. Any "i

Answer 1

If, in case, you are using java8 then you may use;

resolve(() -> people.get(0).getAddress().getPostalCode());
    .ifPresent(System.out::println);

:
public static  Optional resolve(Supplier resolver) {
    try {
        T result = resolver.get();
        return Optional.ofNullable(result);
    }
    catch (NullPointerException e) {
        return Optional.empty();
    }
}

REF: avoid null checks