使用Stream API Java 8进行嵌套对象转换

import java.util.List;
import java.util.stream.Collectors;

public class Main {
    public static void main(String[] args) {
        List<Person> persons = List.of(
                new Person("John", 25, new Address("123 Street", "City1")),
                new Person("Jane", 30, new Address("456 Avenue", "City2")),
                new Person("Bob", 35, new Address("789 Road", "City3"))
        );

        List<PersonDTO> dtos = persons.stream()
                .map(person -> new PersonDTO(person.getName(), person.getAddress().getCity()))
                .collect(Collectors.toList());

        dtos.forEach(System.out::println);
    }
}

class Person {
    private String name;
    private int age;
    private Address address;

    // constructor, getters, setters
}

class Address {
    private String street;
    private String city;

    // constructor, getters, setters
}

class PersonDTO {
    private String name;
    private String city;

    // constructor, getters, setters

    @Override
    public String toString() {
        return "PersonDTO{" +
                "name='" + name + '\'' +
                ", city='" + city + '\'' +
                '}';
    }
}