如何使用收集器进行分组

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

public class GroupingExample {
    public static void main(String[] args) {
        // 创建一个包含对象的集合
        List<Person> persons = Arrays.asList(
                new Person("Alice", 25),
                new Person("Bob", 30),
                new Person("Alice", 35),
                new Person("Bob", 40)
        );

        // 使用收集器进行分组
        Map<String, List<Person>> groupedPersons = persons.stream()
                .collect(Collectors.groupingBy(Person::getName));

        // 打印分组结果
        groupedPersons.forEach((name, group) -> {
            System.out.println("Group: " + name);
            group.forEach(System.out::println);
            System.out.println();
        });
    }

    static 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;
        }

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

Group: Alice
Person{name='Alice', age=25}
Person{name='Alice', age=35}

Group: Bob
Person{name='Bob', age=30}
Person{name='Bob', age=40}