Java で簡単な学生休暇承認システムを実装するにはどうすればよいですか?

public class LeaveApprovalSystem {
    // 定义学生列表，保存已注册的学生信息
    List<Student> studentList;
    // 定义教师列表，保存已注册的教师信息
    List<Teacher> teacherList;
    // 定义请假申请列表，保存已提交的请假申请
    List<LeaveApplication> leaveApplicationList;
    
    // 学生注册功能
    public void registerStudent(Student student) {
        studentList.add(student);
    }
    
    // 教师注册功能
    public void registerTeacher(Teacher teacher) {
        teacherList.add(teacher);
    }
    
    // 学生提交请假申请功能
    public void submitLeaveApplication(Student student, LeaveApplication leaveApplication) {
        leaveApplicationList.add(leaveApplication);
    }
    
    // 教师审批请假申请功能
    public void approveLeaveApplication(Teacher teacher, LeaveApplication leaveApplication) {
        leaveApplication.setApprovalStatus("Approved");
    }
    
    // 教师拒绝请假申请功能
    public void rejectLeaveApplication(Teacher teacher, LeaveApplication leaveApplication) {
        leaveApplication.setApprovalStatus("Rejected");
    }
    
    // 学生取消请假申请功能
    public void cancelLeaveApplication(Student student, LeaveApplication leaveApplication) {
        leaveApplicationList.remove(leaveApplication);
    }
    
    // 学生查看请假申请状态功能
    public String getLeaveApplicationStatus(Student student, LeaveApplication leaveApplication) {
        return leaveApplication.getApprovalStatus();
    }
}

public class Main {
    public static void main(String[] args) {
        LeaveApprovalSystem system = new LeaveApprovalSystem();
        Student student = new Student("001", "张三");
        Teacher teacher = new Teacher("1001", "李老师");
        LeaveApplication leaveApplication = new LeaveApplication("2021-01-01", "2021-01-05", "家里有事情");
        
        system.registerStudent(student);
        system.registerTeacher(teacher);
        system.submitLeaveApplication(student, leaveApplication);
        
        system.approveLeaveApplication(teacher, leaveApplication);
        
        String status = system.getLeaveApplicationStatus(student, leaveApplication);
        System.out.println("请假申请状态：" + status);
    }
}