diff --git a/src/data/NotesDatabaseHelper.java b/src/data/NotesDatabaseHelper.java new file mode 100644 index 0000000..ed22d53 --- /dev/null +++ b/src/data/NotesDatabaseHelper.java @@ -0,0 +1,365 @@ +/* + * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net) + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + + package net.micode.notes.data; + + import android.content.ContentValues;//就是用于保存一些数据（string boolean byte double float int long short ...）信息，这些信息可以被数据库操作时使用。 + import android.content.Context;//加载和访问资源。（android中主要是这两个功能，但是这里具体不清楚） + import android.database.sqlite.SQLiteDatabase;//主要提供了对应于添加、删除、更新、查询的操作方法： insert()、delete()、update()和query()。配合content.values + import android.database.sqlite.SQLiteOpenHelper;//用来管理数据的创建和版本更新 + import android.util.Log; + + import net.micode.notes.data.Notes.DataColumns; + import net.micode.notes.data.Notes.DataConstants; + import net.micode.notes.data.Notes.NoteColumns; + //数据库操作，用SQLOpenhelper,对一些note和文件进行数据库的操作，比如删除文件后，将文件里的note也相应删除 + + public class NotesDatabaseHelper extends SQLiteOpenHelper { + private static final String DB_NAME = "note.db"; + + private static final int DB_VERSION = 4; + + public interface TABLE { //接口，分成note和data，在后面的程序里分别使用过 + public static final String NOTE = "note"; + + public static final String DATA = "data"; + } + + private static final String TAG = "NotesDatabaseHelper"; + + private static NotesDatabaseHelper mInstance; + + private static final String CREATE_NOTE_TABLE_SQL = + "CREATE TABLE " + TABLE.NOTE + "(" + + NoteColumns.ID + " INTEGER PRIMARY KEY," + + NoteColumns.PARENT_ID + " INTEGER NOT NULL DEFAULT 0," + + NoteColumns.ALERTED_DATE + " INTEGER NOT NULL DEFAULT 0," + + NoteColumns.BG_COLOR_ID + " INTEGER NOT NULL DEFAULT 0," + + NoteColumns.CREATED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," + + NoteColumns.HAS_ATTACHMENT + " INTEGER NOT NULL DEFAULT 0," + + NoteColumns.MODIFIED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," + + NoteColumns.NOTES_COUNT + " INTEGER NOT NULL DEFAULT 0," + + NoteColumns.SNIPPET + " TEXT NOT NULL DEFAULT ''," + + NoteColumns.TYPE + " INTEGER NOT NULL DEFAULT 0," + + NoteColumns.WIDGET_ID + " INTEGER NOT NULL DEFAULT 0," + + NoteColumns.WIDGET_TYPE + " INTEGER NOT NULL DEFAULT -1," + + NoteColumns.SYNC_ID + " INTEGER NOT NULL DEFAULT 0," + + NoteColumns.LOCAL_MODIFIED + " INTEGER NOT NULL DEFAULT 0," + + NoteColumns.ORIGIN_PARENT_ID + " INTEGER NOT NULL DEFAULT 0," + + NoteColumns.GTASK_ID + " TEXT NOT NULL DEFAULT ''," + + NoteColumns.VERSION + " INTEGER NOT NULL DEFAULT 0" + + ")";//数据库中需要存储的项目的名称，就相当于创建一个表格的表头的内容。 + + private static final String CREATE_DATA_TABLE_SQL = + "CREATE TABLE " + TABLE.DATA + "(" + + DataColumns.ID + " INTEGER PRIMARY KEY," + + DataColumns.MIME_TYPE + " TEXT NOT NULL," + + DataColumns.NOTE_ID + " INTEGER NOT NULL DEFAULT 0," + + NoteColumns.CREATED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," + + NoteColumns.MODIFIED_DATE + " INTEGER NOT NULL DEFAULT (strftime('%s','now') * 1000)," + + DataColumns.CONTENT + " TEXT NOT NULL DEFAULT ''," + + DataColumns.DATA1 + " INTEGER," + + DataColumns.DATA2 + " INTEGER," + + DataColumns.DATA3 + " TEXT NOT NULL DEFAULT ''," + + DataColumns.DATA4 + " TEXT NOT NULL DEFAULT ''," + + DataColumns.DATA5 + " TEXT NOT NULL DEFAULT ''" + + ")";//和上面的功能一样，主要是存储的项目不同 + + private static final String CREATE_DATA_NOTE_ID_INDEX_SQL = + "CREATE INDEX IF NOT EXISTS note_id_index ON " + + TABLE.DATA + "(" + DataColumns.NOTE_ID + ");";//存储便签编号的一个数据表格 + + /** + * Increase folder's note count when move note to the folder + */ + private static final String NOTE_INCREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER = + "CREATE TRIGGER increase_folder_count_on_update "+ + " AFTER UPDATE OF " + NoteColumns.PARENT_ID + " ON " + TABLE.NOTE + + " BEGIN " + + " UPDATE " + TABLE.NOTE + + " SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + " + 1" + + " WHERE " + NoteColumns.ID + "=new." + NoteColumns.PARENT_ID + ";" + + " END";//在文件夹中移入一个Note之后需要更改的数据的表格。 + + /** + * Decrease folder's note count when move note from folder + */ + private static final String NOTE_DECREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER = + "CREATE TRIGGER decrease_folder_count_on_update " + + " AFTER UPDATE OF " + NoteColumns.PARENT_ID + " ON " + TABLE.NOTE + + " BEGIN " + + " UPDATE " + TABLE.NOTE + + " SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + "-1" + + " WHERE " + NoteColumns.ID + "=old." + NoteColumns.PARENT_ID + + " AND " + NoteColumns.NOTES_COUNT + ">0" + ";" + + " END";//在文件夹中移出一个Note之后需要更改的数据的表格。 + + /** + * Increase folder's note count when insert new note to the folder + */ + private static final String NOTE_INCREASE_FOLDER_COUNT_ON_INSERT_TRIGGER = + "CREATE TRIGGER increase_folder_count_on_insert " + + " AFTER INSERT ON " + TABLE.NOTE + + " BEGIN " + + " UPDATE " + TABLE.NOTE + + " SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + " + 1" + + " WHERE " + NoteColumns.ID + "=new." + NoteColumns.PARENT_ID + ";" + + " END";//在文件夹中插入一个Note之后需要更改的数据的表格。 + + /** + * Decrease folder's note count when delete note from the folder + */ + private static final String NOTE_DECREASE_FOLDER_COUNT_ON_DELETE_TRIGGER = + "CREATE TRIGGER decrease_folder_count_on_delete " + + " AFTER DELETE ON " + TABLE.NOTE + + " BEGIN " + + " UPDATE " + TABLE.NOTE + + " SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + "-1" + + " WHERE " + NoteColumns.ID + "=old." + NoteColumns.PARENT_ID + + " AND " + NoteColumns.NOTES_COUNT + ">0;" + + " END";//在文件夹中删除一个Note之后需要更改的数据的表格。 + + /** + * Update note's content when insert data with type {@link DataConstants#NOTE} + */ + private static final String DATA_UPDATE_NOTE_CONTENT_ON_INSERT_TRIGGER = + "CREATE TRIGGER update_note_content_on_insert " + + " AFTER INSERT ON " + TABLE.DATA + + " WHEN new." + DataColumns.MIME_TYPE + "='" + DataConstants.NOTE + "'" + + " BEGIN" + + " UPDATE " + TABLE.NOTE + + " SET " + NoteColumns.SNIPPET + "=new." + DataColumns.CONTENT + + " WHERE " + NoteColumns.ID + "=new." + DataColumns.NOTE_ID + ";" + + " END";//在文件夹中对一个Note导入新的数据之后需要更改的数据的表格。 + + /** + * Update note's content when data with {@link DataConstants#NOTE} type has changed + */ + private static final String DATA_UPDATE_NOTE_CONTENT_ON_UPDATE_TRIGGER = + "CREATE TRIGGER update_note_content_on_update " + + " AFTER UPDATE ON " + TABLE.DATA + + " WHEN old." + DataColumns.MIME_TYPE + "='" + DataConstants.NOTE + "'" + + " BEGIN" + + " UPDATE " + TABLE.NOTE + + " SET " + NoteColumns.SNIPPET + "=new." + DataColumns.CONTENT + + " WHERE " + NoteColumns.ID + "=new." + DataColumns.NOTE_ID + ";" + + " END";//Note数据被修改后需要更改的数据的表格。 + + /** + * Update note's content when data with {@link DataConstants#NOTE} type has deleted + */ + private static final String DATA_UPDATE_NOTE_CONTENT_ON_DELETE_TRIGGER = + "CREATE TRIGGER update_note_content_on_delete " + + " AFTER delete ON " + TABLE.DATA + + " WHEN old." + DataColumns.MIME_TYPE + "='" + DataConstants.NOTE + "'" + + " BEGIN" + + " UPDATE " + TABLE.NOTE + + " SET " + NoteColumns.SNIPPET + "=''" + + " WHERE " + NoteColumns.ID + "=old." + DataColumns.NOTE_ID + ";" + + " END";//Note数据被删除后需要更改的数据的表格。 + + /** + * Delete datas belong to note which has been deleted + */ + private static final String NOTE_DELETE_DATA_ON_DELETE_TRIGGER = + "CREATE TRIGGER delete_data_on_delete " + + " AFTER DELETE ON " + TABLE.NOTE + + " BEGIN" + + " DELETE FROM " + TABLE.DATA + + " WHERE " + DataColumns.NOTE_ID + "=old." + NoteColumns.ID + ";" + + " END";//删除已删除的便签的数据后需要更改的数据的表格。 + + /** + * Delete notes belong to folder which has been deleted + */ + private static final String FOLDER_DELETE_NOTES_ON_DELETE_TRIGGER = + "CREATE TRIGGER folder_delete_notes_on_delete " + + " AFTER DELETE ON " + TABLE.NOTE + + " BEGIN" + + " DELETE FROM " + TABLE.NOTE + + " WHERE " + NoteColumns.PARENT_ID + "=old." + NoteColumns.ID + ";" + + " END";//删除已删除的文件夹的便签后需要更改的数据的表格。 + + /** + * Move notes belong to folder which has been moved to trash folder + */ + private static final String FOLDER_MOVE_NOTES_ON_TRASH_TRIGGER = + "CREATE TRIGGER folder_move_notes_on_trash " + + " AFTER UPDATE ON " + TABLE.NOTE + + " WHEN new." + NoteColumns.PARENT_ID + "=" + Notes.ID_TRASH_FOLER + + " BEGIN" + + " UPDATE " + TABLE.NOTE + + " SET " + NoteColumns.PARENT_ID + "=" + Notes.ID_TRASH_FOLER + + " WHERE " + NoteColumns.PARENT_ID + "=old." + NoteColumns.ID + ";" + + " END";//还原垃圾桶中便签后需要更改的数据的表格。 + + public NotesDatabaseHelper(Context context) { + super(context, DB_NAME, null, DB_VERSION); + }//构造函数，传入数据库的名称和版本 + + public void createNoteTable(SQLiteDatabase db) { + db.execSQL(CREATE_NOTE_TABLE_SQL); + reCreateNoteTableTriggers(db); + createSystemFolder(db); + Log.d(TAG, "note table has been created"); + }//创建表格（用来存储标签属性） + + private void reCreateNoteTableTriggers(SQLiteDatabase db) { + db.execSQL("DROP TRIGGER IF EXISTS increase_folder_count_on_update"); + db.execSQL("DROP TRIGGER IF EXISTS decrease_folder_count_on_update"); + db.execSQL("DROP TRIGGER IF EXISTS decrease_folder_count_on_delete"); + db.execSQL("DROP TRIGGER IF EXISTS delete_data_on_delete"); + db.execSQL("DROP TRIGGER IF EXISTS increase_folder_count_on_insert"); + db.execSQL("DROP TRIGGER IF EXISTS folder_delete_notes_on_delete"); + db.execSQL("DROP TRIGGER IF EXISTS folder_move_notes_on_trash"); + + db.execSQL(NOTE_INCREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER); + db.execSQL(NOTE_DECREASE_FOLDER_COUNT_ON_UPDATE_TRIGGER); + db.execSQL(NOTE_DECREASE_FOLDER_COUNT_ON_DELETE_TRIGGER); + db.execSQL(NOTE_DELETE_DATA_ON_DELETE_TRIGGER); + db.execSQL(NOTE_INCREASE_FOLDER_COUNT_ON_INSERT_TRIGGER); + db.execSQL(FOLDER_DELETE_NOTES_ON_DELETE_TRIGGER); + db.execSQL(FOLDER_MOVE_NOTES_ON_TRASH_TRIGGER); + }//execSQL是数据库操作的API，主要是更改行为的SQL语句。 + //在这里主要是用来重新创建上述定义的表格用的，先删除原来有的数据库的触发器再重新创建新的数据库 + + private void createSystemFolder(SQLiteDatabase db) { + ContentValues values = new ContentValues(); + + /** + * call record foler for call notes + */ + values.put(NoteColumns.ID, Notes.ID_CALL_RECORD_FOLDER); + values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM); + db.insert(TABLE.NOTE, null, values); + + /** + * root folder which is default folder + */ + values.clear(); + values.put(NoteColumns.ID, Notes.ID_ROOT_FOLDER); + values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM); + db.insert(TABLE.NOTE, null, values); + + /** + * temporary folder which is used for moving note + */ + values.clear(); + values.put(NoteColumns.ID, Notes.ID_TEMPARAY_FOLDER); + values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM); + db.insert(TABLE.NOTE, null, values); + + /** + * create trash folder + */ + values.clear(); + values.put(NoteColumns.ID, Notes.ID_TRASH_FOLER); + values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM); + db.insert(TABLE.NOTE, null, values); + }//创建几个系统文件夹 + + public void createDataTable(SQLiteDatabase db) { + db.execSQL(CREATE_DATA_TABLE_SQL); + reCreateDataTableTriggers(db); + db.execSQL(CREATE_DATA_NOTE_ID_INDEX_SQL); + Log.d(TAG, "data table has been created"); + }//创建表格（用来存储标签内容） + + private void reCreateDataTableTriggers(SQLiteDatabase db) { + db.execSQL("DROP TRIGGER IF EXISTS update_note_content_on_insert"); + db.execSQL("DROP TRIGGER IF EXISTS update_note_content_on_update"); + db.execSQL("DROP TRIGGER IF EXISTS update_note_content_on_delete"); + + db.execSQL(DATA_UPDATE_NOTE_CONTENT_ON_INSERT_TRIGGER); + db.execSQL(DATA_UPDATE_NOTE_CONTENT_ON_UPDATE_TRIGGER); + db.execSQL(DATA_UPDATE_NOTE_CONTENT_ON_DELETE_TRIGGER); + }//同上面的execSQL + + static synchronized NotesDatabaseHelper getInstance(Context context) { + if (mInstance == null) { + mInstance = new NotesDatabaseHelper(context); + } + return mInstance; + }//上网查是为解决同一时刻只能有一个线程执行. + //在写程序库代码时，有时有一个类需要被所有的其它类使用， + //但又要求这个类只能被实例化一次，是个服务类，定义一次，其它类使用同一个这个类的实例 + + @Override + public void onCreate(SQLiteDatabase db) { + createNoteTable(db); + createDataTable(db); + }//实现两个表格（上面创建的两个表格） + + @Override + public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { + boolean reCreateTriggers = false; + boolean skipV2 = false; + + if (oldVersion == 1) { + upgradeToV2(db); + skipV2 = true; // this upgrade including the upgrade from v2 to v3 + oldVersion++; + } + + if (oldVersion == 2 && !skipV2) { + upgradeToV3(db); + reCreateTriggers = true; + oldVersion++; + } + + if (oldVersion == 3) { + upgradeToV4(db); + oldVersion++; + } + + if (reCreateTriggers) { + reCreateNoteTableTriggers(db); + reCreateDataTableTriggers(db); + } + + if (oldVersion != newVersion) { + throw new IllegalStateException("Upgrade notes database to version " + newVersion + + "fails"); + } + }//数据库版本的更新（数据库内容的更改） + + private void upgradeToV2(SQLiteDatabase db) { + db.execSQL("DROP TABLE IF EXISTS " + TABLE.NOTE); + db.execSQL("DROP TABLE IF EXISTS " + TABLE.DATA); + createNoteTable(db); + createDataTable(db); + }//更新到V2版本 + + private void upgradeToV3(SQLiteDatabase db) { + // drop unused triggers + db.execSQL("DROP TRIGGER IF EXISTS update_note_modified_date_on_insert"); + db.execSQL("DROP TRIGGER IF EXISTS update_note_modified_date_on_delete"); + db.execSQL("DROP TRIGGER IF EXISTS update_note_modified_date_on_update"); + // add a column for gtask id + db.execSQL("ALTER TABLE " + TABLE.NOTE + " ADD COLUMN " + NoteColumns.GTASK_ID + + " TEXT NOT NULL DEFAULT ''"); + // add a trash system folder + ContentValues values = new ContentValues(); + values.put(NoteColumns.ID, Notes.ID_TRASH_FOLER); + values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM); + db.insert(TABLE.NOTE, null, values); + }//更新到V3版本 + + private void upgradeToV4(SQLiteDatabase db) { + db.execSQL("ALTER TABLE " + TABLE.NOTE + " ADD COLUMN " + NoteColumns.VERSION + + " INTEGER NOT NULL DEFAULT 0"); + }//更新到V4版本,但是不知道V2、V3、V4是什么意思 + } \ No newline at end of file diff --git a/src/data/NotesProvider.java b/src/data/NotesProvider.java new file mode 100644 index 0000000..278d363 --- /dev/null +++ b/src/data/NotesProvider.java @@ -0,0 +1,336 @@ +/* + * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net) + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + + package net.micode.notes.data; + + import android.app.SearchManager; + import android.content.ContentProvider; + import android.content.ContentUris; + import android.content.ContentValues; + import android.content.Intent; + import android.content.UriMatcher; + import android.database.Cursor; + import android.database.sqlite.SQLiteDatabase; + import android.net.Uri; + import android.text.TextUtils; + import android.util.Log; + + import net.micode.notes.R; + import net.micode.notes.data.Notes.DataColumns; + import net.micode.notes.data.Notes.NoteColumns; + import net.micode.notes.data.NotesDatabaseHelper.TABLE; + //为存储和获取数据提供接口。可以在不同的应用程序之间共享数据 + //ContentProvider提供的方法 + //query：查询 + //insert：插入 + //update：更新 + //delete：删除 + //getType：得到数据类型 + public class NotesProvider extends ContentProvider { + // UriMatcher用于匹配Uri + private static final UriMatcher mMatcher; + + private NotesDatabaseHelper mHelper; + + private static final String TAG = "NotesProvider"; + + private static final int URI_NOTE = 1; + private static final int URI_NOTE_ITEM = 2; + private static final int URI_DATA = 3; + private static final int URI_DATA_ITEM = 4; + + private static final int URI_SEARCH = 5; + private static final int URI_SEARCH_SUGGEST = 6; + + static { + // 创建UriMatcher时，调用UriMatcher(UriMatcher.NO_MATCH)表示不匹配任何路径的返回码 + mMatcher = new UriMatcher(UriMatcher.NO_MATCH); + // 把需要匹配Uri路径全部给注册上 + mMatcher.addURI(Notes.AUTHORITY, "note", URI_NOTE); + mMatcher.addURI(Notes.AUTHORITY, "note/#", URI_NOTE_ITEM); + mMatcher.addURI(Notes.AUTHORITY, "data", URI_DATA); + mMatcher.addURI(Notes.AUTHORITY, "data/#", URI_DATA_ITEM); + mMatcher.addURI(Notes.AUTHORITY, "search", URI_SEARCH); + mMatcher.addURI(Notes.AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY, URI_SEARCH_SUGGEST); + mMatcher.addURI(Notes.AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY + "/*", URI_SEARCH_SUGGEST); + } + + /** + * x'0A' represents the '\n' character in sqlite. For title and content in the search result, + * we will trim '\n' and white space in order to show more information. + */ + // 声明 NOTES_SEARCH_PROJECTION + private static final String NOTES_SEARCH_PROJECTION = NoteColumns.ID + "," + + NoteColumns.ID + " AS " + SearchManager.SUGGEST_COLUMN_INTENT_EXTRA_DATA + "," + + "TRIM(REPLACE(" + NoteColumns.SNIPPET + ", x'0A','')) AS " + SearchManager.SUGGEST_COLUMN_TEXT_1 + "," + + "TRIM(REPLACE(" + NoteColumns.SNIPPET + ", x'0A','')) AS " + SearchManager.SUGGEST_COLUMN_TEXT_2 + "," + + R.drawable.search_result + " AS " + SearchManager.SUGGEST_COLUMN_ICON_1 + "," + + "'" + Intent.ACTION_VIEW + "' AS " + SearchManager.SUGGEST_COLUMN_INTENT_ACTION + "," + + "'" + Notes.TextNote.CONTENT_TYPE + "' AS " + SearchManager.SUGGEST_COLUMN_INTENT_DATA; + // 声明NOTES_SNIPPET_SEARCH_QUERY + private static String NOTES_SNIPPET_SEARCH_QUERY = "SELECT " + NOTES_SEARCH_PROJECTION + + " FROM " + TABLE.NOTE + + " WHERE " + NoteColumns.SNIPPET + " LIKE ?" + + " AND " + NoteColumns.PARENT_ID + "<>" + Notes.ID_TRASH_FOLER + + " AND " + NoteColumns.TYPE + "=" + Notes.TYPE_NOTE; + + @Override + // Context只有在onCreate()中才被初始化 + // 对mHelper进行实例化 + public boolean onCreate() { + mHelper = NotesDatabaseHelper.getInstance(getContext()); + return true; + } + + @Override + // 查询uri在数据库中对应的位置 + public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, + String sortOrder) { + Cursor c = null; + // 获取可读数据库 + SQLiteDatabase db = mHelper.getReadableDatabase(); + String id = null; + // 匹配查找uri + switch (mMatcher.match(uri)) { + // 对于不同的匹配值，在数据库中查找相应的条目 + case URI_NOTE: + c = db.query(TABLE.NOTE, projection, selection, selectionArgs, null, null, + sortOrder); + break; + case URI_NOTE_ITEM: + id = uri.getPathSegments().get(1); + c = db.query(TABLE.NOTE, projection, NoteColumns.ID + "=" + id + + parseSelection(selection), selectionArgs, null, null, sortOrder); + break; + case URI_DATA: + c = db.query(TABLE.DATA, projection, selection, selectionArgs, null, null, + sortOrder); + break; + case URI_DATA_ITEM: + id = uri.getPathSegments().get(1); + c = db.query(TABLE.DATA, projection, DataColumns.ID + "=" + id + + parseSelection(selection), selectionArgs, null, null, sortOrder); + break; + case URI_SEARCH: + case URI_SEARCH_SUGGEST: + if (sortOrder != null || projection != null) { + // 不合法的参数异常 + throw new IllegalArgumentException( + "do not specify sortOrder, selection, selectionArgs, or projection" + "with this query"); + } + + String searchString = null; + if (mMatcher.match(uri) == URI_SEARCH_SUGGEST) { + if (uri.getPathSegments().size() > 1) { + // getPathSegments()方法得到一个String的List， + // 在uri.getPathSegments().get(1)为第2个元素 + searchString = uri.getPathSegments().get(1); + } + } else { + searchString = uri.getQueryParameter("pattern"); + } + + if (TextUtils.isEmpty(searchString)) { + return null; + } + + try { + searchString = String.format("%%%s%%", searchString); + c = db.rawQuery(NOTES_SNIPPET_SEARCH_QUERY, + new String[] { searchString }); + } catch (IllegalStateException ex) { + Log.e(TAG, "got exception: " + ex.toString()); + } + break; + default: + // 抛出异常 + throw new IllegalArgumentException("Unknown URI " + uri); + } + if (c != null) { + c.setNotificationUri(getContext().getContentResolver(), uri); + } + return c; + } + + @Override + // 插入一个uri + public Uri insert(Uri uri, ContentValues values) { + // 获得可写的数据库 + SQLiteDatabase db = mHelper.getWritableDatabase(); + long dataId = 0, noteId = 0, insertedId = 0; + switch (mMatcher.match(uri)) { + // 新增一个条目 + case URI_NOTE: + insertedId = noteId = db.insert(TABLE.NOTE, null, values); + break; + // 如果存在，查找NOTE_ID + case URI_DATA: + if (values.containsKey(DataColumns.NOTE_ID)) { + noteId = values.getAsLong(DataColumns.NOTE_ID); + } else { + Log.d(TAG, "Wrong data format without note id:" + values.toString()); + } + insertedId = dataId = db.insert(TABLE.DATA, null, values); + break; + default: + throw new IllegalArgumentException("Unknown URI " + uri); + } + // Notify the note uri + // notifyChange获得一个ContextResolver对象并且更新里面的内容 + if (noteId > 0) { + getContext().getContentResolver().notifyChange( + ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId), null); + } + + // Notify the data uri + if (dataId > 0) { + getContext().getContentResolver().notifyChange( + ContentUris.withAppendedId(Notes.CONTENT_DATA_URI, dataId), null); + } + + // 返回插入的uri的路径 + return ContentUris.withAppendedId(uri, insertedId); + } + + @Override + // 删除一个uri + public int delete(Uri uri, String selection, String[] selectionArgs) { + //Uri代表要操作的数据，Android上可用的每种资源 -包括 图像、视频片段、音频资源等都可以用Uri来表示。 + int count = 0; + String id = null; + // 获得可写的数据库 + SQLiteDatabase db = mHelper.getWritableDatabase(); + boolean deleteData = false; + switch (mMatcher.match(uri)) { + case URI_NOTE: + selection = "(" + selection + ") AND " + NoteColumns.ID + ">0 "; + count = db.delete(TABLE.NOTE, selection, selectionArgs); + break; + case URI_NOTE_ITEM: + id = uri.getPathSegments().get(1); + /** + * ID that smaller than 0 is system folder which is not allowed to + * trash + */ + long noteId = Long.valueOf(id); + if (noteId <= 0) { + break; + } + count = db.delete(TABLE.NOTE, + NoteColumns.ID + "=" + id + parseSelection(selection), selectionArgs); + break; + case URI_DATA: + count = db.delete(TABLE.DATA, selection, selectionArgs); + deleteData = true; + break; + case URI_DATA_ITEM: + id = uri.getPathSegments().get(1); + count = db.delete(TABLE.DATA, + DataColumns.ID + "=" + id + parseSelection(selection), selectionArgs); + deleteData = true; + break; + default: + throw new IllegalArgumentException("Unknown URI " + uri); + } + if (count > 0) { + if (deleteData) { + getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null); + } + getContext().getContentResolver().notifyChange(uri, null); + } + return count; + } + + @Override + // 更新一个uri + public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) { + int count = 0; + String id = null; + SQLiteDatabase db = mHelper.getWritableDatabase(); + boolean updateData = false; + switch (mMatcher.match(uri)) { + case URI_NOTE: + increaseNoteVersion(-1, selection, selectionArgs); + count = db.update(TABLE.NOTE, values, selection, selectionArgs); + break; + case URI_NOTE_ITEM: + id = uri.getPathSegments().get(1); + increaseNoteVersion(Long.valueOf(id), selection, selectionArgs); + count = db.update(TABLE.NOTE, values, NoteColumns.ID + "=" + id + + parseSelection(selection), selectionArgs); + break; + case URI_DATA: + count = db.update(TABLE.DATA, values, selection, selectionArgs); + updateData = true; + break; + case URI_DATA_ITEM: + id = uri.getPathSegments().get(1); + count = db.update(TABLE.DATA, values, DataColumns.ID + "=" + id + + parseSelection(selection), selectionArgs); + updateData = true; + break; + default: + throw new IllegalArgumentException("Unknown URI " + uri); + } + + if (count > 0) { + if (updateData) { + getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null); + } + getContext().getContentResolver().notifyChange(uri, null); + } + return count; + } + + // 将字符串解析成规定格式 + private String parseSelection(String selection) { + return (!TextUtils.isEmpty(selection) ? " AND (" + selection + ')' : ""); + } + + //增加一个noteVersion + private void increaseNoteVersion(long id, String selection, String[] selectionArgs) { + StringBuilder sql = new StringBuilder(120); + sql.append("UPDATE "); + sql.append(TABLE.NOTE); + sql.append(" SET "); + sql.append(NoteColumns.VERSION); + sql.append("=" + NoteColumns.VERSION + "+1 "); + + if (id > 0 || !TextUtils.isEmpty(selection)) { + sql.append(" WHERE "); + } + if (id > 0) { + sql.append(NoteColumns.ID + "=" + String.valueOf(id)); + } + if (!TextUtils.isEmpty(selection)) { + String selectString = id > 0 ? parseSelection(selection) : selection; + for (String args : selectionArgs) { + selectString = selectString.replaceFirst("\\?", args); + } + sql.append(selectString); + } + + // execSQL()方法可以执行insert、delete、update和CREATE TABLE之类有更改行为的SQL语句 + mHelper.getWritableDatabase().execSQL(sql.toString()); + } + + @Override + public String getType(Uri uri) { + // TODO Auto-generated method stub + return null; + } + + } \ No newline at end of file