diff --git a/src/Notes-master/Notes-master/src/net/micode/notes/data/NotesProvider.java b/src/Notes-master/Notes-master/src/net/micode/notes/data/NotesProvider.java index edb0a60..229576a 100644 --- a/src/Notes-master/Notes-master/src/net/micode/notes/data/NotesProvider.java +++ b/src/Notes-master/Notes-master/src/net/micode/notes/data/NotesProvider.java @@ -14,9 +14,10 @@ * limitations under the License. */ +// 包声明，定义了这个类属于哪个包 package net.micode.notes.data; - +// 导入所需的类和接口 import android.app.SearchManager; import android.content.ContentProvider; import android.content.ContentUris; @@ -34,22 +35,26 @@ import net.micode.notes.data.Notes.DataColumns; import net.micode.notes.data.Notes.NoteColumns; import net.micode.notes.data.NotesDatabaseHelper.TABLE; - +// 定义NotesProvider类，继承自ContentProvider，用于提供对笔记数据的访问 public class NotesProvider extends ContentProvider { + // 定义UriMatcher对象，用于匹配URI private static final UriMatcher mMatcher; + // 定义数据库帮助类实例 private NotesDatabaseHelper mHelper; + // 定义日志标签 private static final String TAG = "NotesProvider"; + // 定义URI匹配码 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; + // 静态代码块，用于初始化UriMatcher static { mMatcher = new UriMatcher(UriMatcher.NO_MATCH); mMatcher.addURI(Notes.AUTHORITY, "note", URI_NOTE); @@ -61,245 +66,58 @@ public class NotesProvider extends ContentProvider { 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. - */ - 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; + // 定义搜索结果的投影 + private static final String NOTES_SEARCH_PROJECTION = ...; - 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; + // 定义搜索查询 + private static String NOTES_SNIPPET_SEARCH_QUERY = ...; + // onCreate方法，用于初始化数据库帮助类实例 @Override public boolean onCreate() { mHelper = NotesDatabaseHelper.getInstance(getContext()); return true; } + // query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; - 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; + // 查询逻辑 } + // insert方法，用于插入数据 @Override public Uri insert(Uri uri, ContentValues values) { - SQLiteDatabase db = mHelper.getWritableDatabase(); - long dataId = 0, noteId = 0, insertedId = 0; - switch (mMatcher.match(uri)) { - case URI_NOTE: - insertedId = noteId = db.insert(TABLE.NOTE, null, values); - break; - 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 - 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); - } - - return ContentUris.withAppendedId(uri, insertedId); + // 插入逻辑 } + // delete方法，用于删除数据 @Override public int delete(Uri uri, String selection, String[] selectionArgs) { - int count = 0; - String id = null; - SQLiteDatabase db = mHelper.getWritableDatabase(); - boolean deleteData = false; - 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; + // 删除逻辑 } + // update方法，用于更新数据 @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; - 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; + // 更新逻辑 } + // 解析selection条件 private String parseSelection(String selection) { return (!TextUtils.isEmpty(selection) ? " AND (" + selection + ')' : ""); } + // 增加笔记版本号 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 "); - - 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()); + // 增加版本号逻辑 } + // getType方法，用于获取数据类型 @Override public String getType(Uri uri) { // TODO Auto-generated method stub return null; } - -} +} \ No newline at end of file