/* * 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; // 自定义ContentProvider，用于提供对Notes数据库的访问 public class NotesProvider extends ContentProvider { // Uri匹配器，用于区分不同的URI请求 private static final UriMatcher mMatcher; // 数据库帮助类实例，用于操作数据库 private NotesDatabaseHelper mHelper; // 日志标签 private static final String TAG = "NotesProvider"; // 定义不同的URI类型 private static final int URI_NOTE = 1; // 笔记集合URI private static final int URI_NOTE_ITEM = 2; // 单个笔记URI private static final int URI_DATA = 3; // 笔记数据集合URI private static final int URI_DATA_ITEM = 4; // 单个笔记数据URI private static final int URI_SEARCH = 5; // 搜索URI private static final int URI_SEARCH_SUGGEST = 6; // 搜索建议URI // 静态代码块，初始化UriMatcher static { mMatcher = new UriMatcher(UriMatcher.NO_MATCH); 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); } // 搜索投影列，用于搜索建议 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; // 搜索查询语句 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; // ContentProvider创建时调用 @Override public boolean onCreate() { mHelper = NotesDatabaseHelper.getInstance(getContext()); return true; } // 查询方法 @Override public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) { Cursor c = null; SQLiteDatabase db = mHelper.getReadableDatabase(); String id = null; // 根据URI类型执行不同的查询操作 switch (mMatcher.match(uri)) { case URI_NOTE: // 查询笔记集合 c = db.query(TABLE.NOTE, projection, selection, selectionArgs, null, null, sortOrder); break; case URI_NOTE_ITEM: // 查询单个笔记 id = uri.getPathSegments().get(1); c = db.query(TABLE.NOTE, projection, NoteColumns.ID + "=" + id + parseSelection(selection), selectionArgs, null, null, sortOrder); break; case URI_DATA: // 查询笔记数据集合 c = db.query(TABLE.DATA, projection, selection, selectionArgs, null, null, sortOrder); break; case URI_DATA_ITEM: // 查询单个笔记数据 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: // 搜索或搜索建议，不允许指定排序、选择条件等 if (sortOrder != null || projection != null) { throw new IllegalArgumentException( "do not specify sortOrder, selection, selectionArgs, or projection" + "with this query"); } // 注意：此处缺少实现搜索或搜索建议的代码 break; } // 注意：此处缺少返回Cursor前的null检查和处理代码 return c; } // 注意：其他如insert, update, delete, getType等方法未展示，需根据需求实现 } // 这是一个自定义的ContentProvider类的一部分，用于处理对数据库内容的插入、删除、更新和查询操作。 // 插入数据到数据库 @Override public Uri insert(Uri uri, ContentValues values) { // 获取可写的数据库实例 SQLiteDatabase db = mHelper.getWritableDatabase(); long dataId = 0, noteId = 0, insertedId = 0; // 根据URI匹配器的结果决定插入到哪个表 switch (mMatcher.match(uri)) { case URI_NOTE: // 如果是笔记URI insertedId = noteId = db.insert(TABLE.NOTE, null, values); // 插入到笔记表 break; case URI_DATA: // 如果是数据URI if (values.containsKey(DataColumns.NOTE_ID)) { // 如果包含笔记ID noteId = values.getAsLong(DataColumns.NOTE_ID); // 获取笔记ID } else { Log.d(TAG, "Wrong data format without note id:" + values.toString()); // 记录错误日志 } insertedId = dataId = db.insert(TABLE.DATA, null, values); // 插入到数据表 break; default: throw new IllegalArgumentException("Unknown URI " + uri); // 如果URI未知，抛出异常 } // 如果插入了笔记，通知监听器 if (noteId > 0) { getContext().getContentResolver().notifyChange( ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId), null); } // 如果插入了数据，通知监听器 if (dataId > 0) { getContext().getContentResolver().notifyChange( ContentUris.withAppendedId(Notes.CONTENT_DATA_URI, dataId), null); } // 返回新插入数据的URI return ContentUris.withAppendedId(uri, insertedId); } // 从数据库中删除数据 @Override public int delete(Uri uri, String selection, String[] selectionArgs) { int count = 0; String id = null; SQLiteDatabase db = mHelper.getWritableDatabase(); boolean deleteData = false; // 根据URI匹配器的结果决定从哪个表删除数据 switch (mMatcher.match(uri)) { case URI_NOTE: // 如果是笔记URI selection = "(" + selection + ") AND " + NoteColumns.ID + ">0 "; // 添加额外的筛选条件 count = db.delete(TABLE.NOTE, selection, selectionArgs); // 从笔记表删除 break; case URI_NOTE_ITEM: // 如果是单个笔记项的URI id = uri.getPathSegments().get(1); // 获取笔记ID long noteId = Long.valueOf(id); if (noteId <= 0) { break; // 如果ID无效，则不执行删除 } count = db.delete(TABLE.NOTE, NoteColumns.ID + "=" + id + parseSelection(selection), selectionArgs); // 从笔记表删除单个项 break; case URI_DATA: // 如果是数据URI count = db.delete(TABLE.DATA, selection, selectionArgs); // 从数据表删除 deleteData = true; // 标记为删除了数据 break; case URI_DATA_ITEM: // 如果是单个数据项的URI id = uri.getPathSegments().get(1); // 获取数据ID count = db.delete(TABLE.DATA, DataColumns.ID + "=" + id + parseSelection(selection), selectionArgs); // 从数据表删除单个项 deleteData = true; // 标记为删除了数据 break; default: throw new IllegalArgumentException("Unknown URI " + uri); // 如果URI未知，抛出异常 } // 如果删除了数据，通知监听器 if (count > 0) { if (deleteData) { getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null); // 通知笔记URI的监听器 } getContext().getContentResolver().notifyChange(uri, null); // 通知操作URI的监听器 } return count; // 返回删除的行数 } // 更新数据库中的数据 @Override public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) { int count = 0; String id = null; SQLiteDatabase db = mHelper.getWritableDatabase(); boolean updateData = false; // 根据URI匹配器的结果决定更新哪个表 switch (mMatcher.match(uri)) { case URI_NOTE: // 如果是笔记URI increaseNoteVersion(-1, selection, selectionArgs); // 更新笔记版本（特殊逻辑） count = db.update(TABLE.NOTE, values, selection, selectionArgs); // 更新笔记表 break; case URI_NOTE_ITEM: // 如果是单个笔记项的URI id = uri.getPathSegments().get(1); // 获取笔记ID increaseNoteVersion(Long.valueOf(id), selection, selectionArgs); // 更新笔记版本（特殊逻辑） count = db.update(TABLE.NOTE, values, NoteColumns.ID + "=" + id + parseSelection(selection), selectionArgs); // 更新笔记表中的单个项 break; case URI_DATA: // 如果是数据URI count = db.update(TABLE.DATA, values, selection, selectionArgs); // 更新数据表 updateData = true; // 标记为更新了数据 break; case URI_DATA_ITEM: // 如果是单个数据项的URI id = uri.getPathSegments().get(1); // 获取数据ID count = db.update(TABLE.DATA, values, DataColumns.ID + "=" + id + parseSelection(selection), selectionArgs); // 更新数据表中的单个项 updateData = true; // 标记为更新了数据 break; default: throw new IllegalArgumentException("Unknown URI " + uri); // 如果URI未知，抛出异常 } // 如果更新了数据，通知监听器 if (count > 0) { if (updateData) { getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null); // 通知笔记URI的监听器 } getContext().getContentResolver().notifyChange(uri, null); // 通知操作URI的监听器 } return count; // 返回更新的行数 } // 解析额外的筛选条件字符串 private String parseSelection(String selection) { return (!TextUtils.isEmpty(selection) ? " AND (" + selection + ')' : ""); } // 增加笔记的版本号 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 "); // 更新版本号 // 构建WHERE子句 if (id > 0 || !TextUtils.isEmpty(selection)) { sql.append(" WHERE "); } if (id > 0) { sql.append(NoteColumns.ID + "=" + String.valueOf(id)); // 根据ID更新 } if (!TextUtils.isEmpty(selection)) { String selectString = id > 0 ? parseSelection(selection) : selection; // 解析筛选条件 for (String args : selectionArgs) { selectString = selectString.replaceFirst("\\?", args); // 替换占位符 } sql.append(selectString); // 添加筛选条件 } // 执行SQL语句 mHelper.getWritableDatabase().execSQL(sql.toString()); } // 获取URI的类型（未实现） @Override public String getType(Uri uri) { return null; // 此处应返回MIME类型，但代码未实现 } // 其他方法和成员变量（如mMatcher, TABLE, mHelper等）已省略，假设它们在其他地方定义。