commit ec327db173fbbca2fb795db14ec61f9be4ef1441
Author: Puhan Zhao <3107249095@qq.com>
Date:   Tue Jun 24 10:52:07 2025 +0800

    1

diff --git a/DAL/studentDAL.py b/DAL/studentDAL.py
new file mode 100644
index 0000000..4d47216
--- /dev/null
+++ b/DAL/studentDAL.py
@@ -0,0 +1,288 @@
+from test import Student
+import os.path
+from abc import ABC, abstractmethod
+from datetime import date, datetime
+from typing import List, Dict, Optional
+import json
+import csv
+
+class IStudentDAL(ABC):
+
+    @abstractmethod
+    def get_by_id(self, id: str) -> Optional[[Student]]:
+        pass
+
+    @abstractmethod
+    def get_by_stu_id(self, stu_id: str) -> Optional[Student]:
+        pass
+
+    @abstractmethod
+    def get_all(self) -> List[Student]:
+        pass
+
+    @abstractmethod
+    def add(self, student: Student) -> bool:
+        pass
+
+    @abstractmethod
+    def delete(self, id: str) -> bool:
+        pass
+
+    @abstractmethod
+    def delete_by_stu_id(self, stu_id: str) -> bool:
+        pass
+
+    @abstractmethod
+    def update(self, student: Student) -> bool:
+        pass
+
+    @abstractmethod
+    def is_exist(self, id: str) -> bool:
+        pass
+
+    @abstractmethod
+    def is_exist_stu_id(self, stu_id: str) -> bool:
+        pass
+
+    @abstractmethod
+    def import_from_json(self, file_path: str) -> List[Dict]:
+        pass
+
+    @abstractmethod
+    def export_to_json(self, file_path: str) -> bool:
+        pass
+
+    @abstractmethod
+    def import_from_csv(self, file_path: str) -> List[Dict]:
+        pass
+
+    @abstractmethod
+    def export_to_csv(self, file_path: str) -> bool:
+        pass
+
+class JsonStudentDAL(IStudentDAL):
+
+    def __init__(self, file_path: str):
+        self.file_path = file_path
+        self._ensure_file_exists()
+
+    def _ensure_file_exists(self):
+        if not os.path.exists(self.file_path):
+            with open(self.file_path, 'w', encoding='utf-8') as f:
+                json.dump([], f, ensure_ascii=False)
+
+    def _load(self) -> List[Dict]:
+        with open(self.file_path, 'r', encoding='utf-8') as f:
+            return json.load(f)
+
+    def _save(self, data: List[Dict]):
+        with open(self.file_path, 'w', encoding='utf-8') as f:
+            json.dump(data, f, ensure_ascii=False, indent=2)
+
+    def get_by_id(self, id: str) -> Optional[Student]:
+        data = self._load()
+        for item in data:
+            if item['id'] == id:
+                return Student.from_dict(item)
+        return None
+
+    def get_by_stu_id(self, stu_id: str) -> Optional[Student]:
+        data = self._load()
+        for item in data:
+            if item['stu_id'] == stu_id:
+                return Student.from_dict(item)
+        return None
+
+    def get_all(self) -> List[Student]:
+        return [Student.from_dict(item) for item in self._load()]
+
+    def add(self, student: Student) -> bool:
+        data = self._load()
+        if self.is_exist(student.id):
+            return False
+
+        data.append(student.to_dict())
+        self._save(data)
+        return True
+
+    def delete(self, id: str) -> bool:
+        data = self._load()
+        new_data = [item for item in data if item['id'] != id]
+        if len(data) == len(new_data):
+            return False
+
+        self._save(new_data)
+        return True
+
+    def delete_by_stu_id(self, stu_id: str) -> bool:
+        data = self._load()
+        new_data = [item for item in data if item['stu_id'] != stu_id]
+        if len(data) == len(new_data):
+            return False
+
+        self._save(new_data)
+        return True
+
+    def update(self, student: Student) -> bool:
+        data = self._load()
+        updated = False
+
+        for i, item in enumerate(data):
+            if item['id'] == student.id:
+                data[i] = student.to_dict()
+                updated = True
+                break
+
+        if updated:
+            self._save(data)
+        return updated
+
+    def is_exist(self, id: str) -> bool:
+        return any(item['id'] == id for item in self._load())
+
+    def is_exist_stu_id(self, stu_id: str) -> bool:
+        return any(item['stu_id'] == stu_id for item in self._load())
+
+    def import_from_json(self, file_path: str) -> List[Dict]:
+        with open(file_path, 'r', encoding='utf-8') as f:
+            return json.load(f)
+
+    def export_to_json(self, file_path: str) -> bool:
+        try:
+            with open(file_path, 'w', encoding='utf-8') as f:
+                json.dump(self._load(), f, ensure_ascii=False, indent=2)
+            return True
+        except:
+            return False
+
+class CsvStudentDAL(IStudentDAL):
+    """CSV格式数据访问实现类"""
+
+    FIELD_TYPES = {
+        'id': str,
+        'stu_id': str,
+        'name': str,
+        'age': int,
+        'gender': str,
+        'height': float,
+        'weight': float
+    }
+
+    def __init__(self, file_path: str):
+        self.file_path = file_path
+        self._ensure_file_exists()
+
+    def _ensure_file_exists(self):
+        """确保CSV文件存在并包含表头"""
+        if not os.path.exists(self.file_path):
+            with open(self.file_path, 'w', encoding='utf-8-sig', newline='') as f:
+                writer = csv.DictWriter(f, fieldnames=self.FIELD_TYPES.keys())
+                writer.writeheader()
+
+    def _convert_row(self, row: Dict) -> Dict:
+        """转换CSV行的数据类型"""
+        converted = {}
+        for field, dtype in self.FIELD_TYPES.items():
+            value = row.get(field)
+            if value is None or value == '':
+                converted[field] = None
+            else:
+                try:
+                    converted[field] = dtype(value)
+                except (ValueError, TypeError):
+                    converted[field] = None
+        return converted
+
+    def _load(self) -> List[Dict]:
+        """从CSV文件加载数据"""
+        with open(self.file_path, 'r', encoding='utf-8-sig') as f:
+            reader = csv.DictReader(f)
+            return [self._convert_row(row) for row in reader]
+
+    def _save(self, data: List[Dict]):
+        """保存数据到CSV文件"""
+        with open(self.file_path, 'w', encoding='utf-8-sig', newline='') as f:
+            writer = csv.DictWriter(f, fieldnames=self.FIELD_TYPES.keys())
+            writer.writeheader()
+            writer.writerows(data)
+
+    def get_by_id(self, id: str) -> Optional[Student]:
+        data = self._load()
+        for item in data:
+            if item['id'] == id:
+                return Student.from_dict(item)
+        return None
+
+    def get_by_stu_id(self, stu_id: str) -> Optional[Student]:
+        data = self._load()
+        for item in data:
+            if item['stu_id'] == stu_id:
+                return Student.from_dict(item)
+        return None
+
+    def get_all(self) -> List[Student]:
+        return [Student.from_dict(item) for item in self._load()]
+
+    def add(self, student: Student) -> bool:
+        data = self._load()
+        if self.is_exist(student.id):
+            return False
+
+        data.append(student.to_dict())
+        self._save(data)
+        return True
+
+    def delete(self, id: str) -> bool:
+        data = self._load()
+        new_data = [item for item in data if item['id'] != id]
+        if len(data) == len(new_data):
+            return False
+
+        self._save(new_data)
+        return True
+
+    def delete_by_stu_id(self, stu_id: str) -> bool:
+        data = self._load()
+        new_data = [item for item in data if item['stu_id'] != stu_id]
+        if len(data) == len(new_data):
+            return False
+
+        self._save(new_data)
+        return True
+
+    def update(self, student: Student) -> bool:
+        data = self._load()
+        updated = False
+
+        for i, item in enumerate(data):
+            if item['id'] == student.id:
+                data[i] = student.to_dict()
+                updated = True
+                break
+
+        if updated:
+            self._save(data)
+        return updated
+
+    def is_exist(self, id: str) -> bool:
+        return any(item['id'] == id for item in self._load())
+
+    def is_exist_stu_id(self, stu_id: str) -> bool:
+        return any(item['stu_id'] == stu_id for item in self._load())
+
+    def import_from_csv(self, file_path: str) -> List[Dict]:
+        with open(file_path, 'r', encoding='utf-8-sig') as f:
+            reader = csv.DictReader(f)
+            return [self._convert_row(row) for row in reader]
+
+    def export_to_csv(self, file_path: str) -> bool:
+        try:
+            data = self._load()
+            with open(file_path, 'w', encoding='utf-8-sig', newline='') as f:
+                writer = csv.DictWriter(f, fieldnames=self.FIELD_TYPES.keys())
+                writer.writeheader()
+                writer.writerows(data)
+            return True
+        except:
+            return False
+