Type: INTEGER (long)
@@ -169,7 +174,7 @@ public class Notes { public static final String PASSWORD = "password"; public static final String IMPORTANCE = "importance"; - } + }//便签的各种属性 /* * 便签数据在数据库中的表头 */ @@ -245,7 +250,7 @@ public class Notes { *Type: TEXT
*/ public static final String DATA5 = "data5"; - } + }//一个便签内部各种数据类型 public static final class TextNote implements DataColumns { /** @@ -261,7 +266,7 @@ public class Notes { public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/text_note"; public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/text_note"); - } + }//一种是文本textnote public static final class CallNote implements DataColumns { /** @@ -281,5 +286,5 @@ public class Notes { public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/call_note"; public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/call_note"); - } + }//另一种是通话类型的callnote } diff --git a/src/Notes/app/src/main/java/net/micode/notes/data/NotesDatabaseHelper.java b/src/Notes/app/src/main/java/net/micode/notes/data/NotesDatabaseHelper.java index ffe5d57..bedbf65 100644 --- a/src/Notes/app/src/main/java/net/micode/notes/data/NotesDatabaseHelper.java +++ b/src/Notes/app/src/main/java/net/micode/notes/data/NotesDatabaseHelper.java @@ -21,17 +21,17 @@ import android.content.Context; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteOpenHelper; import android.util.Log; - +//引用了同一个包中的另一个子包Notes中一些接口 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 public class NotesDatabaseHelper extends SQLiteOpenHelper { private static final String DB_NAME = "note.db"; private static final int DB_VERSION = 4; - + //接口两部分一个Note一个DATA public interface TABLE { public static final String NOTE = "note"; @@ -41,7 +41,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper { private static final String TAG = "NotesDatabaseHelper"; private static NotesDatabaseHelper mInstance; - + //基于NoteColumn创建一个NOTE_TABLE表格，并附上初始数据 private static final String CREATE_NOTE_TABLE_SQL = "CREATE TABLE " + TABLE.NOTE + "(" + NoteColumns.ID + " INTEGER PRIMARY KEY," + @@ -62,7 +62,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper { NoteColumns.GTASK_ID + " TEXT NOT NULL DEFAULT ''," + NoteColumns.VERSION + " INTEGER NOT NULL DEFAULT 0" + ")"; - + //主要基于datacolumn来创建DATA_TABLE private static final String CREATE_DATA_TABLE_SQL = "CREATE TABLE " + TABLE.DATA + "(" + DataColumns.ID + " INTEGER PRIMARY KEY," + @@ -77,7 +77,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper { DataColumns.DATA4 + " TEXT NOT NULL DEFAULT ''," + DataColumns.DATA5 + " TEXT NOT NULL DEFAULT ''" + ")"; - + //这个数据是关于INDEX编号的 private static final String CREATE_DATA_NOTE_ID_INDEX_SQL = "CREATE INDEX IF NOT EXISTS note_id_index ON " + TABLE.DATA + "(" + DataColumns.NOTE_ID + ");"; @@ -93,7 +93,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper { " SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + " + 1" + " WHERE " + NoteColumns.ID + "=new." + NoteColumns.PARENT_ID + ";" + " END"; - + //移入note时触发，修改一系列数据，从哪来之类的 /** * Decrease folder's note count when move note from folder */ @@ -106,7 +106,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper { " WHERE " + NoteColumns.ID + "=old." + NoteColumns.PARENT_ID + " AND " + NoteColumns.NOTES_COUNT + ">0" + ";" + " END"; - + //移除Note时触发，与上面移入对应 /** * Increase folder's note count when insert new note to the folder */ @@ -118,7 +118,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper { " SET " + NoteColumns.NOTES_COUNT + "=" + NoteColumns.NOTES_COUNT + " + 1" + " WHERE " + NoteColumns.ID + "=new." + NoteColumns.PARENT_ID + ";" + " END"; - + //插入Note /** * Decrease folder's note count when delete note from the folder */ @@ -131,7 +131,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper { " WHERE " + NoteColumns.ID + "=old." + NoteColumns.PARENT_ID + " AND " + NoteColumns.NOTES_COUNT + ">0;" + " END"; - + //删除note /** * Update note's content when insert data with type {@link DataConstants#NOTE} */ @@ -144,7 +144,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper { " SET " + NoteColumns.SNIPPET + "=new." + DataColumns.CONTENT + " WHERE " + NoteColumns.ID + "=new." + DataColumns.NOTE_ID + ";" + " END"; - + //当给note插入新数据时触发 /** * Update note's content when data with {@link DataConstants#NOTE} type has changed */ @@ -156,7 +156,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper { " UPDATE " + TABLE.NOTE + " SET " + NoteColumns.SNIPPET + "=new." + DataColumns.CONTENT + " WHERE " + NoteColumns.ID + "=new." + DataColumns.NOTE_ID + ";" + - " END"; + " END";//note数据被修改update /** * Update note's content when data with {@link DataConstants#NOTE} type has deleted @@ -169,7 +169,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper { " UPDATE " + TABLE.NOTE + " SET " + NoteColumns.SNIPPET + "=''" + " WHERE " + NoteColumns.ID + "=old." + DataColumns.NOTE_ID + ";" + - " END"; + " END";//更新已经删除的便签的数据 /** * Delete datas belong to note which has been deleted @@ -180,7 +180,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper { " BEGIN" + " DELETE FROM " + TABLE.DATA + " WHERE " + DataColumns.NOTE_ID + "=old." + NoteColumns.ID + ";" + - " END"; + " END";//删除 已经被删除的便签的数据 /** * Delete notes belong to folder which has been deleted @@ -191,7 +191,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper { " BEGIN" + " DELETE FROM " + TABLE.NOTE + " WHERE " + NoteColumns.PARENT_ID + "=old." + NoteColumns.ID + ";" + - " END"; + " END";//删除 已删除folder文件夹 中的便签要修改的数据 /** * Move notes belong to folder which has been moved to trash folder @@ -204,12 +204,12 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper { " UPDATE " + TABLE.NOTE + " SET " + NoteColumns.PARENT_ID + "=" + Notes.ID_TRASH_FOLER + " WHERE " + NoteColumns.PARENT_ID + "=old." + NoteColumns.ID + ";" + - " END"; + " END";//移动trash_folder中的便签 public NotesDatabaseHelper(Context context) { super(context, DB_NAME, null, DB_VERSION); } - + //构造函数 public void createNoteTable(SQLiteDatabase db) { db.execSQL(CREATE_NOTE_TABLE_SQL); reCreateNoteTableTriggers(db); @@ -233,7 +233,7 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper { 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); - } + }//数据库操作的API，重新创建 private void createSystemFolder(SQLiteDatabase db) { ContentValues values = new ContentValues(); @@ -268,14 +268,14 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper { values.put(NoteColumns.ID, Notes.ID_TRASH_FOLER); values.put(NoteColumns.TYPE, Notes.TYPE_SYSTEM); db.insert(TABLE.NOTE, null, values); - } + }//创建系统文件夹 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"); - } + }//创建数据表格 private void reCreateDataTableTriggers(SQLiteDatabase db) { db.execSQL("DROP TRIGGER IF EXISTS update_note_content_on_insert"); @@ -285,20 +285,20 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper { 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); - } + }//类似于recreatenotetable，重新创建触发器 static synchronized NotesDatabaseHelper getInstance(Context context) { if (mInstance == null) { mInstance = new NotesDatabaseHelper(context); } return mInstance; - } + }//sync同步，同一时刻只有一个线程执行 @Override public void onCreate(SQLiteDatabase db) { createNoteTable(db); createDataTable(db); - } + }//创建Note Data两个表格 @Override public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { @@ -331,14 +331,14 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper { throw new IllegalStateException("Upgrade notes database to version " + newVersion + "fails"); } - } + }//数据库版本更新 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 private void upgradeToV3(SQLiteDatabase db) { // drop unused triggers @@ -353,10 +353,10 @@ public class NotesDatabaseHelper extends SQLiteOpenHelper { 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 private void upgradeToV4(SQLiteDatabase db) { db.execSQL("ALTER TABLE " + TABLE.NOTE + " ADD COLUMN " + NoteColumns.VERSION + " INTEGER NOT NULL DEFAULT 0"); - } + }//更新到V4 } diff --git a/src/Notes/app/src/main/java/net/micode/notes/data/NotesProvider.java b/src/Notes/app/src/main/java/net/micode/notes/data/NotesProvider.java index edb0a60..6897999 100644 --- a/src/Notes/app/src/main/java/net/micode/notes/data/NotesProvider.java +++ b/src/Notes/app/src/main/java/net/micode/notes/data/NotesProvider.java @@ -1,22 +1,5 @@ -/* - * 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; @@ -33,9 +16,15 @@ 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; @@ -51,7 +40,9 @@ public class NotesProvider extends ContentProvider { 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); @@ -65,33 +56,40 @@ public class NotesProvider extends ContentProvider { * 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; - + + 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; + + " 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) { + 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); @@ -113,6 +111,7 @@ public class NotesProvider extends ContentProvider { 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"); } @@ -120,6 +119,8 @@ public class NotesProvider extends ContentProvider { 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 { @@ -139,6 +140,7 @@ public class NotesProvider extends ContentProvider { } break; default: + // 抛出异常 throw new IllegalArgumentException("Unknown URI " + uri); } if (c != null) { @@ -148,13 +150,17 @@ public class NotesProvider extends ContentProvider { } @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); @@ -167,6 +173,7 @@ public class NotesProvider extends ContentProvider { 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); @@ -178,13 +185,17 @@ public class NotesProvider extends ContentProvider { 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)) { @@ -228,6 +239,7 @@ public class NotesProvider extends ContentProvider { } @Override + // 更新一个uri public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) { int count = 0; String id = null; @@ -267,10 +279,12 @@ public class NotesProvider extends ContentProvider { 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 "); @@ -293,6 +307,7 @@ public class NotesProvider extends ContentProvider { 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()); } @@ -302,4 +317,4 @@ public class NotesProvider extends ContentProvider { return null; } -} +} \ No newline at end of file