How to avoid checking for null values in method chaining? [duplicate]

Answer 1

You could use Optional here, but it creates one Optional object at each step.

boolean isValid = Optional.ofNullable(country)
    .map(country -> country.getCity()) //Or use method reference Country::getCity
    .map(city -> city.getSchool())
    .map(school -> school.getStudent())
    .map(student -> true)
    .orElse(false);

//OR
boolean isValid = Optional.ofNullable(country)
                      .map(..)
                      ....
                      .isPresent();