diff --git a/Notes.java b/Notes.java
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+/*
+ * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
+ * 版权声明，说明本代码是由MiCode开源社区提供并遵循Apache 2.0许可证。
+ */
+
+package net.micode.notes.data;  // 包声明，表示该类属于net.micode.notes.data包
+
+import android.net.Uri;  // 导入Uri类，用于处理URI
+
+public class Notes {
+    // 定义常量，用于表示笔记、文件夹和系统类型
+    public static final String AUTHORITY = "micode_notes";  
+    public static final String TAG = "Notes";  
+    public static final int TYPE_NOTE     = 0;  // 笔记类型
+    public static final int TYPE_FOLDER   = 1;  // 文件夹类型
+    public static final int TYPE_SYSTEM   = 2;  // 系统类型
+
+    /**
+     * 以下是系统文件夹的标识符
+     * ID_ROOT_FOLDER 是默认文件夹
+     * ID_TEMPARAY_FOLDER 用于存储没有归类的笔记
+     * ID_CALL_RECORD_FOLDER 用于存储通话记录
+     */
+    public static final int ID_ROOT_FOLDER = 0;
+    public static final int ID_TEMPARAY_FOLDER = -1;
+    public static final int ID_CALL_RECORD_FOLDER = -2;
+    public static final int ID_TRASH_FOLER = -3;  // 回收站文件夹
+
+    // Intent中传递的数据常量
+    public static final String INTENT_EXTRA_ALERT_DATE = "net.micode.notes.alert_date";  
+    public static final String INTENT_EXTRA_BACKGROUND_ID = "net.micode.notes.background_color_id";
+    public static final String INTENT_EXTRA_WIDGET_ID = "net.micode.notes.widget_id";  
+    public static final String INTENT_EXTRA_WIDGET_TYPE = "net.micode.notes.widget_type";
+    public static final String INTENT_EXTRA_FOLDER_ID = "net.micode.notes.folder_id";
+    public static final String INTENT_EXTRA_CALL_DATE = "net.micode.notes.call_date";  
+
+    // 小部件类型
+    public static final int TYPE_WIDGET_INVALIDE      = -1;
+    public static final int TYPE_WIDGET_2X            = 0;
+    public static final int TYPE_WIDGET_4X            = 1;
+
+    // 数据常量，指示笔记和通话记录的数据类型
+    public static class DataConstants {
+        public static final String NOTE = TextNote.CONTENT_ITEM_TYPE;  // 文本笔记类型
+        public static final String CALL_NOTE = CallNote.CONTENT_ITEM_TYPE;  // 通话记录类型
+    }
+
+    // 查询所有笔记和文件夹的URI
+    public static final Uri CONTENT_NOTE_URI = Uri.parse("content://" + AUTHORITY + "/note");
+
+    // 查询数据的URI
+    public static final Uri CONTENT_DATA_URI = Uri.parse("content://" + AUTHORITY + "/data");
+
+    public interface NoteColumns {
+        /**
+         * 定义笔记和文件夹的数据库列
+         * 每个字段后面有说明其数据类型
+         */
+
+        public static final String ID = "_id";  // 唯一ID
+        public static final String PARENT_ID = "parent_id";  // 父级ID
+        public static final String CREATED_DATE = "created_date";  // 创建日期
+        public static final String MODIFIED_DATE = "modified_date";  // 修改日期
+        public static final String ALERTED_DATE = "alert_date";  // 提醒日期
+        public static final String SNIPPET = "snippet";  // 文件夹名或笔记内容
+        public static final String WIDGET_ID = "widget_id";  // 小部件ID
+        public static final String WIDGET_TYPE = "widget_type";  // 小部件类型
+        public static final String BG_COLOR_ID = "bg_color_id";  // 背景颜色ID
+        public static final String HAS_ATTACHMENT = "has_attachment";  // 是否有附件
+        public static final String NOTES_COUNT = "notes_count";  // 文件夹内笔记数量
+        public static final String TYPE = "type";  // 类型：笔记或文件夹
+        public static final String SYNC_ID = "sync_id";  // 同步ID
+        public static final String LOCAL_MODIFIED = "local_modified";  // 本地修改标志
+        public static final String ORIGIN_PARENT_ID = "origin_parent_id";  // 原始父级ID
+        public static final String GTASK_ID = "gtask_id";  // GTask ID
+        public static final String VERSION = "version";  // 版本
+    }
+
+    public interface DataColumns {
+        /**
+         * 定义数据表的列，主要用于存储附件或其他类型的数据
+         */
+        public static final String ID = "_id";  // 唯一ID
+        public static final String MIME_TYPE = "mime_type";  // 数据的MIME类型
+        public static final String NOTE_ID = "note_id";  // 对应笔记的ID
+        public static final String CREATED_DATE = "created_date";  // 创建日期
+        public static final String MODIFIED_DATE = "modified_date";  // 修改日期
+        public static final String CONTENT = "content";  // 数据内容
+        public static final String DATA1 = "data1";  
+        public static final String DATA2 = "data2";  
+        public static final String DATA3 = "data3"; 
+        public static final String DATA4 = "data4";  
+        public static final String DATA5 = "data5";      }
+
+    // 文本笔记的实现
+    public static final class TextNote implements DataColumns {
+        public static final String MODE = DATA1;  // 标记是否为待办事项
+        public static final int MODE_CHECK_LIST = 1;  // 待办事项模式
+
+        public static final String CONTENT_TYPE = "vnd.android.cursor.dir/text_note";  // 文本笔记内容类型
+        public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/text_note";  // 单项文本笔记内容类型
+        public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/text_note");  // 文本笔记的URI
+    }
+
+    // 通话记录笔记的实现
+    public static final class CallNote implements DataColumns {
+        public static final String CALL_DATE = DATA1;  // 通话日期
+        public static final String PHONE_NUMBER = DATA3;  // 电话号码
+
+        public static final String CONTENT_TYPE = "vnd.android.cursor.dir/call_note";  // 通话记录内容类型
+        public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/call_note";  // 单项通话记录内容类型
+        public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/call_note");  // 通话记录的URI
+    }
+}