diff --git a/Java/TodoListApp/src/DatabaseManager.java b/Java/TodoListApp/src/DatabaseManager.java
index 2105d8b..9a5482e 100644
--- a/Java/TodoListApp/src/DatabaseManager.java
+++ b/Java/TodoListApp/src/DatabaseManager.java
@@ -3,8 +3,11 @@ package TodoListApp.src;
 import java.sql.*;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.logging.Logger;
+import java.util.logging.Level;
 
 public class DatabaseManager {
+    private static final Logger LOGGER = Logger.getLogger(DatabaseManager.class.getName());
     private static final String URL = "jdbc:mysql://localhost:3306/TodoList";
     private static final String USER = "root";
     private static final String PASSWORD = "123456";
@@ -13,23 +16,27 @@ public class DatabaseManager {
         try {
             Class.forName("com.mysql.cj.jdbc.Driver");
         } catch (ClassNotFoundException e) {
-            e.printStackTrace();
+            LOGGER.log(Level.SEVERE, "MySQL JDBC 驱动程序未找到", e);
+            throw new RuntimeException("无法初始化数据库连接", e);
         }
     }
 
-    public void addTodo(String description) throws SQLException {
+    public void addTodo(String description) {
         String sql = "INSERT INTO todos (description) VALUES (?)";
-        try (Connection conn = DriverManager.getConnection(URL, USER, PASSWORD);
+        try (Connection conn = getConnection();
              PreparedStatement pstmt = conn.prepareStatement(sql)) {
             pstmt.setString(1, description);
             pstmt.executeUpdate();
+        } catch (SQLException e) {
+            LOGGER.log(Level.SEVERE, "添加待办事项时发生错误", e);
+            throw new RuntimeException("无法添加待办事项", e);
         }
     }
 
-    public List<TodoItem> getAllTodos() throws SQLException {
+    public List<TodoItem> getAllTodos() {
         List<TodoItem> todos = new ArrayList<>();
         String sql = "SELECT * FROM todos";
-        try (Connection conn = DriverManager.getConnection(URL, USER, PASSWORD);
+        try (Connection conn = getConnection();
              Statement stmt = conn.createStatement();
              ResultSet rs = stmt.executeQuery(sql)) {
             while (rs.next()) {
@@ -37,25 +44,43 @@ public class DatabaseManager {
                 String description = rs.getString("description");
                 todos.add(new TodoItem(id, description));
             }
+        } catch (SQLException e) {
+            LOGGER.log(Level.SEVERE, "获取所有待办事项时发生错误", e);
+            throw new RuntimeException("无法获取待办事项列表", e);
         }
         return todos;
     }
 
-    public void removeTodo(int id) throws SQLException {
+    public void removeTodo(int id) {
         String sql = "DELETE FROM todos WHERE id = ?";
-        try (Connection conn = DriverManager.getConnection(URL, USER, PASSWORD);
+        try (Connection conn = getConnection();
              PreparedStatement pstmt = conn.prepareStatement(sql)) {
             pstmt.setInt(1, id);
             pstmt.executeUpdate();
+        } catch (SQLException e) {
+            LOGGER.log(Level.SEVERE, "删除待办事项时发生错误", e);
+            throw new RuntimeException("无法删除待办事项", e);
         }
     }
 
-    public void markAsCompleted(int id) throws SQLException {
+    public void markAsCompleted(int id) {
         String sql = "UPDATE todos SET completed = true WHERE id = ?";
-        try (Connection conn = DriverManager.getConnection(URL, USER, PASSWORD);
+        try (Connection conn = getConnection();
              PreparedStatement pstmt = conn.prepareStatement(sql)) {
             pstmt.setInt(1, id);
             pstmt.executeUpdate();
+        } catch (SQLException e) {
+            LOGGER.log(Level.SEVERE, "标记待办事项为完成时发生错误", e);
+            throw new RuntimeException("无法标记待办事项为完成", e);
+        }
+    }
+
+    private Connection getConnection() throws SQLException {
+        try {
+            return DriverManager.getConnection(URL, USER, PASSWORD);
+        } catch (SQLException e) {
+            LOGGER.log(Level.SEVERE, "无法建立数据库连接", e);
+            throw e;
         }
     }
 }