写出Java语言创建一个学生信息管理系统的代码

以下是一个简单的Java语言创建学生信息管理系统的示例代码：

Student.java

public class Student {
    private String name;
    private int id;
    private double mathScore;
    private double englishScore;
    private double computerScore;

    public Student(String name, int id, double mathScore, double englishScore, double computerScore) {
        this.name = name;
        this.id = id;
        this.mathScore = mathScore;
        this.englishScore = englishScore;
        this.computerScore = computerScore;
    }

    public String getName() {
        return name;
    }

    public int getId() {
        return id;
    }

    public double getMathScore() {
        return mathScore;
    }

    public double getEnglishScore() {
        return englishScore;
    }

    public double getComputerScore() {
        return computerScore;
    }

    public double getTotalScore() {
        return mathScore + englishScore + computerScore;
    }

    public double getAverageScore() {
        return getTotalScore() / 3;
    }
}

StudentManager.java

import java.io.*;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

public class StudentManager {
    private List<Student> studentList;
    private String fileName;

    public StudentManager(String fileName) {
        this.fileName = fileName;
        studentList = new ArrayList<>();
        loadFromFile();
    }

    public void addStudent(String name, int id, double mathScore, double englishScore, double computerScore) {
        Student student = new Student(name, id, mathScore, englishScore, computerScore);
        studentList.add(student);
        saveToFile();
    }

    public void deleteStudent(int id) {
        for (Student student : studentList) {
            if (student.getId() == id) {
                studentList.remove(student);
                saveToFile();
                return;
            }
        }
    }

    public void updateStudent(int id, String name, double mathScore, double englishScore, double computerScore) {
        for (Student student : studentList) {
            if (student.getId() == id) {
                studentList.remove(student);
                Student newStudent = new Student(name, id, mathScore, englishScore, computerScore);
                studentList.add(newStudent);
                saveToFile();
                return;
            }
        }
    }

    public List<Student> queryStudentByName(String name) {
        List<Student> result = new ArrayList<>();
        for (Student student : studentList) {
            if (student.getName().equals(name)) {
                result.add(student);
            }
        }
        return result;
    }

    public List<Student> queryStudentByScore() {
        Collections.sort(studentList, new Comparator<Student>() {
            @Override
            public int compare(Student o1, Student o2) {
                return Double.compare(o2.getTotalScore(), o1.getTotalScore());
            }
        });
        return studentList;
    }

    public void printStudents() {
        for (Student student : studentList) {
            System.out.println(student.getId() + " " + student.getName() + " " + student.getMathScore() + " " + student.getEnglishScore() + " " + student.getComputerScore() + " " + student.getTotalScore() + " " + student.getAverageScore());
        }
    }

    private void loadFromFile() {
        try (BufferedReader reader = new BufferedReader(new FileReader(fileName))) {
            String line;
            while ((line = reader.readLine()) != null) {
                String[] parts = line.split(",");
                if (parts.length == 5) {
                    String name = parts[0];
                    int id = Integer.parseInt(parts[1]);
                    double mathScore = Double.parseDouble(parts[2]);
                    double englishScore = Double.parseDouble(parts[3]);
                    double computerScore = Double.parseDouble(parts[4]);
                    Student student = new Student(name, id, mathScore, englishScore, computerScore);
                    studentList.add(student);
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private void saveToFile() {
        try (BufferedWriter writer = new BufferedWriter(new FileWriter(fileName))) {
            for (Student student : studentList) {
                String line = student.getName() + "," + student.getId() + "," + student.getMathScore() + "," + student.getEnglishScore() + "," + student.getComputerScore();
                writer.write(line);
                writer.newLine();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

Main.java

import java.util.List;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        StudentManager manager = new StudentManager("students.txt");
        Scanner scanner = new Scanner(System.in);

        while (true) {
            System.out.println("请选择操作");
            System.out.println("1. 添加学生");
            System.out.println("2. 删除学生");
            System.out.println("3. 修改学生信息");
            System.out.println("4. 按姓名查询学生");
            System.out.println("5. 按成绩排序");
            System.out.println("6. 显示所有学生信息");
            System.out.println("0. 退出");

            int choice = scanner.nextInt();
            scanner.nextLine();

            switch (choice) {
                case 1:
                    System.out.print("请输入姓名：");
                    String name = scanner.nextLine();
                    System.out.print("请输入学号：");
                    int id = scanner.nextInt();
                    System.out.print("请输入数学成绩：");
                    double mathScore = scanner.nextDouble();
                    System.out.print("请输入英语成绩：");
                    double englishScore = scanner.nextDouble();
                    System.out.print("请输入计算机成绩：");
                    double computerScore = scanner.nextDouble();
                    manager.addStudent(name, id, mathScore, englishScore, computerScore);
                    break;
                case 2:
                    System.out.print("请输入学号：");
                    id = scanner.nextInt();
                    manager.deleteStudent(id);
                    break;
                case 3:
                    System.out.print("请输入学号：");
                    id = scanner.nextInt();
                    scanner.nextLine();
                    System.out.print("请输入姓名：");
                    name = scanner.nextLine();
                    System.out.print("请输入数学成绩：");
                    mathScore = scanner.nextDouble();
                    System.out.print("请输入英语成绩：");
                    englishScore = scanner.nextDouble();
                    System.out.print("请输入计算机成绩：");
                    computerScore = scanner.nextDouble();
                    manager.updateStudent(id, name, mathScore, englishScore, computerScore);
                    break;
                case 4:
                    System.out.print("请输入姓名：");
                    name = scanner.nextLine();
                    List<Student> students = manager.queryStudentByName(name);
                    for (Student student : students) {
                        System.out.println(student.getId() + " " + student.getName() + " " + student.getMathScore() + " " + student.getEnglishScore() + " " + student.getComputerScore() + " " + student.getTotalScore() + " " + student.getAverageScore());
                    }
                    break;
                case 5:
                    students = manager.queryStudentByScore();
                    for (Student student : students) {
                        System.out.println(student.getId() + " " + student.getName() + " " + student.getMathScore() + " " + student.getEnglishScore() + " " + student.getComputerScore() + " " + student.getTotalScore() + " " + student.getAverageScore());
                    }
                    break;
                case 6:
                    manager.printStudents();
                    break;
                case 0:
                    return;
                default:
                    System.out.println("输入错误，请重新输入");
                    break;
            }
        }
    }
}

这个示例代码实现了基本的学生信息管理系统功能，包括添加、删除、修改学生信息，查询学生信息，计算学生的总成绩、平均成绩、排名等，将学生信息存储到文件中。您可以根据自己的需求进行修改和扩展。