Java 8 Streams API - List to Map - Merge键

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

public class Main {
    public static void main(String[] args) {
        List<Person> personList = List.of(
                new Person("Alice", 25),
                new Person("Bob", 30),
                new Person("Alice", 35)
        );

        Map<String, Integer> personMap = personList.stream()
                .collect(Collectors.toMap(
                        Person::getName,
                        Person::getAge,
                        (existingValue, newValue) -> newValue // 使用新值覆盖旧值
                ));

        System.out.println(personMap);
    }
}

class Person {
    private String name;
    private int age;

    public Person(String name, int age) {
        this.name = name;
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public int getAge() {
        return age;
    }
}