编写一个程序，把学生姓名和分数录入map，按分数显示学生名字。定义student类，封装学生姓名和考试分数。java

以下是Java代码实现：

import java.util.*;

class Student {
    private String name;
    private int score;

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

    public String getName() {
        return name;
    }

    public int getScore() {
        return score;
    }
}

public class Main {
    public static void main(String[] args) {
        Map<Integer, String> map = new TreeMap<>(Collections.reverseOrder());
        map.put(90, "Tom");
        map.put(80, "Jerry");
        map.put(95, "Alice");
        map.put(70, "Bob");

        for (Map.Entry<Integer, String> entry : map.entrySet()) {
            System.out.println(entry.getValue() + ": " + entry.getKey());
        }

        List<Student> students = new ArrayList<>();
        students.add(new Student("Tom", 90));
        students.add(new Student("Jerry", 80));
        students.add(new Student("Alice", 95));
        students.add(new Student("Bob", 70));

        Collections.sort(students, new Comparator<Student>() {
            @Override
            public int compare(Student o1, Student o2) {
                return o2.getScore() - o1.getScore();
            }
        });

        for (Student student : students) {
            System.out.println(student.getName() + ": " + student.getScore());
        }
    }
}

这个程序首先使用 `Map` 存储学生姓名和分数，并按照分数从高到低排序输出。然后定义了一个 `Student` 类，封装学生姓名和考试分数，使用 `List` 存储学生对象，并按照分数从高到低排序输出。