Java输入学生姓名，Java成绩，按分数从高到低排序后存储在文件score.txt中。

好的，这个问题可以分为以下几个步骤：

1. 创建一个存储学生信息的类，包括学生姓名和Java成绩两个属性。

public 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;
    }
}

2. 读取用户输入的学生姓名和Java成绩，并将其封装为一个Student对象，然后将所有的Student对象存储在一个List中。

List<Student> students = new ArrayList<>();
Scanner scanner = new Scanner(System.in);

while (true) {
    System.out.println("请输入学生姓名和Java成绩，以空格分隔（输入exit退出）：");
    String input = scanner.nextLine();

    if ("exit".equals(input)) {
        break;
    }

    String[] parts = input.split(" ");
    String name = parts[0];
    int score = Integer.parseInt(parts[1]);

    students.add(new Student(name, score));
}

3. 对List中的学生信息按照Java成绩从高到低进行排序。

Collections.sort(students, new Comparator<Student>() {
    @Override
    public int compare(Student s1, Student s2) {
        return s2.getScore() - s1.getScore();
    }
});

4. 将排序后的学生信息写入文件score.txt中。

try (PrintWriter writer = new PrintWriter("score.txt")) {
    for (Student student : students) {
        writer.println(student.getName() + " " + student.getScore());
    }
} catch (IOException e) {
    e.printStackTrace();
}

完整代码如下：

import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        List<Student> students = new ArrayList<>();
        Scanner scanner = new Scanner(System.in);

        while (true) {
            System.out.println("请输入学生姓名和Java成绩，以空格分隔（输入exit退出）：");
            String input = scanner.nextLine();

            if ("exit".equals(input)) {
                break;
            }

            String[] parts = input.split(" ");
            String name = parts[0];
            int score = Integer.parseInt(parts[1]);

            students.add(new Student(name, score));
        }

        Collections.sort(students, new Comparator<Student>() {
            @Override
            public int compare(Student s1, Student s2) {
                return s2.getScore() - s1.getScore();
            }
        });

        try (PrintWriter writer = new PrintWriter("score.txt")) {
            for (Student student : students) {
                writer.println(student.getName() + " " + student.getScore());
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

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;
    }
}