TestOption.java

import java.util.Optional;

public class TestOption {

    public static void main(String[] args) {
        // Avec option
        System.out.println(getOption()
                .filter(c -> c.age < 35)
                .map(c -> "Age = " + c.age)
                .orElse("Contact not found"));
        
        // Sans option
        Contact c = get();
        if (c != null && c.age < 35) {
            System.out.println("Age = " + c.age);
        } else {
            System.out.println("Contact not found");
        }
    }
    
    public static Contact get() {
        return null;
    }
    
    public static Optional<Contact> getOption() {
        return Optional.empty();
    }
    
    
    public static class Contact {
        public int age;
    }
    
}