写一个Java的代码，关于学生成绩系统的删除学生信息，成绩信息的代码

以下是一个简单的学生成绩系统的Java代码，包括删除学生信息和成绩信息的功能。

import java.util.ArrayList;
import java.util.Scanner;

public class StudentGradeSystem {
    
    static ArrayList<Student> students = new ArrayList<>();
    
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int choice;
        do {
            System.out.println("1. 添加学生信息");
            System.out.println("2. 删除学生信息");
            System.out.println("3. 添加学生成绩");
            System.out.println("4. 删除学生成绩");
            System.out.println("5. 查看学生成绩");
            System.out.println("0. 退出系统");
            System.out.println("请选择功能：");
            choice = scanner.nextInt();
            switch (choice) {
                case 1:
                    addStudent();
                    break;
                case 2:
                    deleteStudent();
                    break;
                case 3:
                    addGrade();
                    break;
                case 4:
                    deleteGrade();
                    break;
                case 5:
                    viewGrade();
                    break;
                case 0:
                    System.out.println("谢谢使用！");
                    break;
                default:
                    System.out.println("输入有误，请重新选择！");
                    break;
            }
        } while (choice != 0);
        scanner.close();
    }

    private static void addStudent() {
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入学生姓名：");
        String name = scanner.nextLine();
        System.out.println("请输入学生学号：");
        String id = scanner.nextLine();
        students.add(new Student(name, id));
        System.out.println("添加成功！");
    }

    private static void deleteStudent() {
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入要删除的学生学号：");
        String id = scanner.nextLine();
        for (Student student : students) {
            if (student.getId().equals(id)) {
                students.remove(student);
                System.out.println("删除成功！");
                return;
            }
        }
        System.out.println("未找到该学生！");
    }

    private static void addGrade() {
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入学生学号：");
        String id = scanner.nextLine();
        for (Student student : students) {
            if (student.getId().equals(id)) {
                System.out.println("请输入科目名称：");
                String subject = scanner.nextLine();
                System.out.println("请输入成绩：");
                double grade = scanner.nextDouble();
                student.addGrade(subject, grade);
                System.out.println("成绩添加成功！");
                return;
            }
        }
        System.out.println("未找到该学生！");
    }

    private static void deleteGrade() {
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入学生学号：");
        String id = scanner.nextLine();
        for (Student student : students) {
            if (student.getId().equals(id)) {
                System.out.println("请输入要删除的科目名称：");
                String subject = scanner.nextLine();
                if (student.deleteGrade(subject)) {
                    System.out.println("成绩删除成功！");
                } else {
                    System.out.println("未找到该科目成绩！");
                }
                return;
            }
        }
        System.out.println("未找到该学生！");
    }

    private static void viewGrade() {
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入学生学号：");
        String id = scanner.nextLine();
        for (Student student : students) {
            if (student.getId().equals(id)) {
                student.printGrades();
                return;
            }
        }
        System.out.println("未找到该学生！");
    }

}

class Student {
    
    private String name;
    private String id;
    private ArrayList<Grade> grades = new ArrayList<>();
    
    public Student(String name, String id) {
        this.name = name;
        this.id = id;
    }
    
    public String getName() {
        return name;
    }
    
    public String getId() {
        return id;
    }
    
    public void addGrade(String subject, double grade) {
        grades.add(new Grade(subject, grade));
    }
    
    public boolean deleteGrade(String subject) {
        for (Grade grade : grades) {
            if (grade.getSubject().equals(subject)) {
                grades.remove(grade);
                return true;
            }
        }
        return false;
    }
    
    public void printGrades() {
        System.out.println("学号：" + id + "，姓名：" + name + "，成绩如下：");
        for (Grade grade : grades) {
            System.out.println(grade.getSubject() + "：" + grade.getGrade());
        }
    }
    
}

class Grade {
    
    private String subject;
    private double grade;
    
    public Grade(String subject, double grade) {
        this.subject = subject;
        this.grade = grade;
    }
    
    public String getSubject() {
        return subject;
    }
    
    public double getGrade() {
        return grade;
    }
    
}