面试题：Java中Stream filter方法基于对象属性过滤的实现

Question

假设有一个包含学生信息的List，学生类Student包含属性name（字符串类型）和age（整数类型）。请使用Java Stream的filter方法，编写代码筛选出年龄大于18岁的学生，并将筛选后的学生姓名收集到一个新的List中。

Answer 1

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

class Student {
    private String name;
    private int age;

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

    public String getName() {
        return name;
    }

    public int getAge() {
        return age;
    }
}

public class Main {
    public static void main(String[] args) {
        List<Student> studentList = new ArrayList<>();
        studentList.add(new Student("Alice", 20));
        studentList.add(new Student("Bob", 16));
        studentList.add(new Student("Charlie", 22));

        List<String> filteredNames = studentList.stream()
               .filter(student -> student.getAge() > 18)
               .map(Student::getName)
               .collect(Collectors.toList());

        System.out.println(filteredNames);
    }
}