From cce68423815d2c636f80ed65a1101125450e0de1 Mon Sep 17 00:00:00 2001 From: pxp26ynaf <1048194975@qq.com> Date: Thu, 11 May 2023 09:58:29 +0800 Subject: [PATCH] =?UTF-8?q?=E4=BB=A3=E7=A0=81=E9=98=85=E8=AF=BB=E4=B8=8E?= =?UTF-8?q?=E6=B3=A8=E9=87=8A?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- NotesProvider.java | 318 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 318 insertions(+) create mode 100644 NotesProvider.java diff --git a/NotesProvider.java b/NotesProvider.java new file mode 100644 index 0000000..b88e617 --- /dev/null +++ b/NotesProvider.java @@ -0,0 +1,318 @@ +/* + * 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; + +//NotesProvider是一个ContentProvider，它提供与Note相关的数据。提供Note的增删改查，以及搜索功能。 +public class NotesProvider extends ContentProvider { + //UriMatcher是用来匹配URI的。通过addURI来添加URI的匹配规则。 + private static final UriMatcher mMatcher; + + + // NotesDatabaseHelper是一个单例的DatabaseHelper，用来管理数据库。 + private NotesDatabaseHelper mHelper; +//TAG用于调试日志。 + private static final String TAG = "NotesProvider"; +//下面定义了6个URI匹配规则。用于匹配Note和Data表，以及搜索功能。 + 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 { + 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); + } + + /** + * 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. + */ + //下面是搜索功能的查询语句。它查询Note表，将查询结果的部分信息用于搜索功能展示。 + 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; + + 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的回调方法，用于初始化DatabaseHelper。 + @Override + public boolean onCreate() { + mHelper = NotesDatabaseHelper.getInstance(getContext()); + return true; + } +//ContentProvider的回调方法，用于查询数据。 + @Override + public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, + String sortOrder) { + Cursor c = null; + SQLiteDatabase db = mHelper.getReadableDatabase(); + String id = null; + //执行对ContentProvider的查询 + //@param uri 请求的内容的URI + //@param projection 结果集中所包含的列 + //@param selection 过滤器 + //@param selectionArgs 过滤器的参数 + //@param sortOrder 排序方式 + //@return 查询结果 + switch (mMatcher.match(uri)) { + 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) { + 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) { + 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: + throw new IllegalArgumentException("Unknown URI " + uri); + } + if (c != null) { + c.setNotificationUri(getContext().getContentResolver(), uri); + } + return c; + } + + @Override + public Uri insert(Uri uri, ContentValues values) { // 插入数据 + SQLiteDatabase db = mHelper.getWritableDatabase(); // 获取可写的数据库实例 + long dataId = 0, noteId = 0, insertedId = 0; // 定义数据ID、笔记ID、插入的ID + switch (mMatcher.match(uri)) { // 根据URI匹配对应的表格 + case URI_NOTE: // 笔记表格 + insertedId = noteId = db.insert(TABLE.NOTE, null, values); // 插入数据并返回插入行的ID + break; + case URI_DATA: // 数据表格 + if (values.containsKey(DataColumns.NOTE_ID)) { // 如果插入的内容包含笔记ID，则获取笔记ID + noteId = values.getAsLong(DataColumns.NOTE_ID); + } else { + Log.d(TAG, "Wrong data format without note id:" + values.toString()); // 如果没有笔记ID，则打印错误信息 + } + insertedId = dataId = db.insert(TABLE.DATA, null, values); // 将数据插入表格并返回行的ID + break; + default: // 不匹配任何表格，则抛出异常 + throw new IllegalArgumentException("Unknown URI " + uri); + } +// 通知URI发生了变化 + if (noteId > 0) { + getContext().getContentResolver().notifyChange( + ContentUris.withAppendedId(Notes.CONTENT_NOTE_URI, noteId), null); + } + if (dataId > 0) { + getContext().getContentResolver().notifyChange( + ContentUris.withAppendedId(Notes.CONTENT_DATA_URI, dataId), null); + } + return ContentUris.withAppendedId(uri, insertedId); // 返回插入内容的URI + } + + @Override + public int delete(Uri uri, String selection, String[] selectionArgs) { // 删除数据 + int count = 0; // 定义删除的行数 + String id = null; + SQLiteDatabase db = mHelper.getWritableDatabase(); // 获取可写的数据库实例 + boolean deleteData = false; + switch (mMatcher.match(uri)) { // 根据URI匹配对应的表格 + case URI_NOTE: // 笔记表格 +// 构建删除所需的条件语句 + selection = "(" + selection + ") AND " + NoteColumns.ID + ">0 "; + count = db.delete(TABLE.NOTE, selection, selectionArgs); // 删除匹配条件的行 + break; + case URI_NOTE_ITEM: // 笔记表格 + id = uri.getPathSegments().get(1); // 获取路径中的ID +/** + * ID that smaller than 0 is system folder which is not allowed to + * trash + */ + long noteId = Long.valueOf(id); + if (noteId <= 0) { // 如果ID小于等于0，则不允许删除 + break; + } + count = db.delete(TABLE.NOTE, + NoteColumns.ID + "=" + id + parseSelection(selection), selectionArgs); // 删除匹配条件的行 + break; + case URI_DATA: // 数据表格 + count = db.delete(TABLE.DATA, selection, selectionArgs); // 删除匹配条件的行 + deleteData = true; + break; + case URI_DATA_ITEM: // 数据表格 + id = uri.getPathSegments().get(1); // 获取路径中的ID + count = db.delete(TABLE.DATA, + DataColumns.ID + "=" + id + parseSelection(selection), selectionArgs); // 删除匹配条件的行 + deleteData = true; + break; + default: // 不匹配任何表格，则抛出异常 + throw new IllegalArgumentException("Unknown URI " + uri); + } + if (count > 0) { // 如果有行被删除 + if (deleteData) { // 如果删除的是数据表格，则需要通知笔记URI发生变化 + getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null); + } +// 通知URI发生了变化 + getContext().getContentResolver().notifyChange(uri, null); + } + return count; // 返回已删除的行数 + } + + @Override + //更新数据 + 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; + } + + private String parseSelection(String selection) { + return (!TextUtils.isEmpty(selection) ? " AND (" + selection + ')' : ""); + } + + 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); + } + + mHelper.getWritableDatabase().execSQL(sql.toString()); + } + + @Override + // 获取URI类型 + public String getType(Uri uri) { + // TODO Auto-generated method stub + return null; + } + +}