Java Optional: example with .ifPresent()

memberFinder.java

public void printMemberNameIfPresent(List<Member> members, int memberId) {
    members.stream()
        .filter(member -> member.getId() == memberId)
        .findFirst()
        .ifPresent(member -> printMemberFullName(member.getFullName()));  // if present, apply the lambda on the value
}

private static void printMemberFullName(String memberFullName) {
    System.out.println(String.format("The member's full name is %s", memberFullName));
}