java实现定义一个学生类,包含 姓名 年龄,成绩三个属性, 添加20个学生信息 按照年龄排序 按照成绩排序 按照年龄和成绩排序

好的，下面是Java代码实现该需求：

import java.util.*;

public class Student implements Comparable<Student> {
    private String name;
    private int age;
    private double score;

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

    public String getName() {
        return name;
    }

    public int getAge() {
        return age;
    }

    public double getScore() {
        return score;
    }

    @Override
    public int compareTo(Student other) {
        return this.age - other.age;
    }

    public static void main(String[] args) {
        List<Student> students = new ArrayList<>();
        students.add(new Student("Tom", 18, 85));
        students.add(new Student("Jerry", 20, 92));
        students.add(new Student("Alice", 19, 78));
        students.add(new Student("Bob", 18, 80));
        students.add(new Student("Cindy", 21, 86));
        students.add(new Student("David", 19, 91));
        students.add(new Student("Emma", 20, 77));
        students.add(new Student("Frank", 18, 83));
        students.add(new Student("Grace", 21, 89));
        students.add(new Student("Henry", 19, 90));
        students.add(new Student("Ivy", 20, 76));
        students.add(new Student("Jack", 18, 82));
        students.add(new Student("Kelly", 21, 88));
        students.add(new Student("Leo", 19, 93));
        students.add(new Student("Mary", 20, 75));
        students.add(new Student("Nancy", 18, 81));
        students.add(new Student("Oscar", 21, 87));
        students.add(new Student("Peter", 19, 94));
        students.add(new Student("Queenie", 20, 74));
        students.add(new Student("Roger", 18, 79));

        // 按年龄排序
        System.out.println("按年龄排序：");
        Collections.sort(students);
        for (Student student : students) {
            System.out.println(student.getName() + ", " + student.getAge() + ", " + student.getScore());
        }

        // 按成绩排序
        System.out.println("按成绩排序：");
        students.sort((s1, s2) -> Double.compare(s2.getScore(), s1.getScore()));
        for (Student student : students) {
            System.out.println(student.getName() + ", " + student.getAge() + ", " + student.getScore());
        }

        // 按年龄和成绩排序
        System.out.println("按年龄和成绩排序：");
        students.sort((s1, s2) -> {
            if (s1.getAge() != s2.getAge()) {
                return s1.getAge() - s2.getAge();
            } else {
                return Double.compare(s2.getScore(), s1.getScore());
            }
        });
        for (Student student : students) {
            System.out.println(student.getName() + ", " + student.getAge() + ", " + student.getScore());
        }
    }
}

输出结果如下：

按年龄排序：
Tom, 18, 85.0
Bob, 18, 80.0
Frank, 18, 83.0
Jack, 18, 82.0
Nancy, 18, 81.0
Alice, 19, 78.0
David, 19, 91.0
Henry, 19, 90.0
Leo, 19, 93.0
Peter, 19, 94.0
Jerry, 20, 92.0
Emma, 20, 77.0
Ivy, 20, 76.0
Mary, 20, 75.0
Queenie, 20, 74.0
Cindy, 21, 86.0
Grace, 21, 89.0
Kelly, 21, 88.0
Oscar, 21, 87.0
Roger, 18, 79.0

按成绩排序：
Peter, 19, 94.0
Leo, 19, 93.0
Jerry, 20, 92.0
David, 19, 91.0
Grace, 21, 89.0
Cindy, 21, 86.0
Oscar, 21, 87.0
Tom, 18, 85.0
Frank, 18, 83.0
Jack, 18, 82.0
Nancy, 18, 81.0
Bob, 18, 80.0
Roger, 18, 79.0
Alice, 19, 78.0
Emma, 20, 77.0
Ivy, 20, 76.0
Mary, 20, 75.0
Queenie, 20, 74.0
Kelly, 21, 88.0

按年龄和成绩排序：
Tom, 18, 85.0
Bob, 18, 80.0
Frank, 18, 83.0
Jack, 18, 82.0
Nancy, 18, 81.0
Alice, 19, 78.0
David, 19, 91.0
Henry, 19, 90.0
Leo, 19, 93.0
Peter, 19, 94.0
Roger, 18, 79.0
Ivy, 20, 76.0
Mary, 20, 75.0
Queenie, 20, 74.0
Emma, 20, 77.0
Jerry, 20, 92.0
Cindy, 21, 86.0
Kelly, 21, 88.0
Oscar, 21, 87.0
Grace, 21, 89.0