java 保存

Java/TodoListApp/TodoListApp.java

@@ -0,0 +1,110 @@
+package TodoListApp;
+import java.util.Scanner;
+
+// 主类
+public class TodoListApp {
+    private static final String ADD_TODO = "1";
+    private static final String LIST_TODOS = "2";
+    private static final String REMOVE_TODO = "3";
+    private static final String MARK_AS_COMPLETED = "4";
+    private static final String SAVE_TODOS = "5";
+    private static final String EXIT = "6";
+
+    private static final TodoListManager manager = new TodoListManager();
+    private static final Scanner scanner = new Scanner(System.in);
+
+    public static void main(String[] args) {
+        boolean exit = false;
+        while (!exit) {
+            printMenu();
+            String choice = scanner.nextLine();
+            switch (choice) {
+                case ADD_TODO:
+                    addTodoUI();
+                    break;
+                case LIST_TODOS:
+                    manager.listTodos();
+                    break;
+                case REMOVE_TODO:
+                    removeTodoUI();
+                    break;
+                case MARK_AS_COMPLETED:
+                    markAsCompletedUI();
+                    break;
+                case SAVE_TODOS:
+                    manager.saveToFile("todos.dat");
+                    break;
+                case EXIT:
+                    exit = true;
+                    System.out.println("退出程序。");
+                    break;
+                default:
+                    System.out.println("无效的选择，请重新输入。");
+            }
+        }
+        scanner.close();
+    }
+
+    // 打印菜单
+    private static void printMenu() {
+        System.out.println("\n===== 简易待办事项管理器 =====");
+        System.out.println("1. 添加待办事项");
+        System.out.println("2. 查看所有待办事项");
+        System.out.println("3. 删除待办事项");
+        System.out.println("4. 标记待办为已完成");
+        System.out.println("5. 保存待办事项（字节流）");
+        System.out.println("6. 退出");
+        System.out.print("请选择操作（1-6）：");
+    }
+
+    // 添加待办事项的用户界面
+    private static void addTodoUI() {
+        String description = getNonEmptyInput("请输入待办事项描述：");
+        try {
+            manager.addTodo(description);
+        } catch (EmptyDescriptionException e) {
+            System.out.println("自定义异常：" + e.getMessage());
+        }
+    }
+
+    // 删除待办事项的用户界面
+    private static void removeTodoUI() {
+        System.out.print("请输入要删除的待办事项编号：");
+        String input = scanner.nextLine().trim();
+        try {
+            int id = Integer.parseInt(input);
+            manager.removeTodo(id);
+        } catch (NumberFormatException e) {
+            try {
+                throw new InvalidIdException("请输入有效的ID编号。");
+            } catch (InvalidIdException ex) {
+                System.out.println("自定义异常：" + ex.getMessage());
+                ;
+            }
+        } catch (TodoNotFoundException e) {
+            System.out.println("自定义异常：" + e.getMessage());
+        }
+    }
+
+    //用于对用户的输入进行提示和预处理的能用方法
+    private static String getNonEmptyInput(String prompt) {
+        System.out.println(prompt);
+        String input = scanner.nextLine().trim();
+        while (input.isEmpty()) {
+            System.out.println("输入不能为空，请重新输入。");
+            System.out.println(prompt);
+            input = scanner.nextLine().trim();
+        }
+        return input;
+    }
+
+    private static void markAsCompletedUI() {
+        String input = getNonEmptyInput("请输入要标记为已完成的待办事项编号：");
+        try {
+            int id = Integer.parseInt(input);
+            manager.markAsCompleted(id);
+        } catch (NumberFormatException e) {
+            System.out.println("请输入有效的数字编号。");
+        }
+    }
+}