/* * 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;//放在data包中 import android.app.SearchManager; //提供对系统搜索的访问 import android.content.ContentProvider; //Android提供的应用程序之间的数据共享 import android.content.ContentUris; //用于获取uri路径后面的ID部分 import android.content.ContentValues; //一种存储机制 import android.content.Intent; //传输 import android.content.UriMatcher;//用于匹配URI import android.database.Cursor; //用于Android数据库的操作 import android.database.sqlite.SQLiteDatabase; //Android数据库管理 import android.net.Uri; //应用程序的跳转 import android.text.TextUtils; //处理字符串，不用考虑正则表达式 import android.util.Log; //打印日志信息 import net.micode.notes.R; import net.micode.notes.data.Notes.DataColumns; //自己包中的类 import net.micode.notes.data.Notes.NoteColumns; //自己包中的类 import net.micode.notes.data.NotesDatabaseHelper.TABLE; //接口 public class NotesProvider extends ContentProvider { //继承于contentprovider private static final UriMatcher mMatcher; //定义一个URImatcher类的私有静态常量对象 private NotesDatabaseHelper mHelper; //一个自己包中的类的私有对象 private static final String TAG = "NotesProvider"; //一个静态常量string类的对象 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 { //静态代码块，在程序创建jvm时就运行，只执行一次 mMatcher = new UriMatcher(UriMatcher.NO_MATCH); //创建，并传入没有匹配的URI的返回码 mMatcher.addURI(Notes.AUTHORITY, "note", URI_NOTE); // mMatcher.addURI(Notes.AUTHORITY, "note/#", URI_NOTE_ITEM); // /#为通配符 mMatcher.addURI(Notes.AUTHORITY, "data", URI_DATA); mMatcher.addURI(Notes.AUTHORITY, "data/#", URI_DATA_ITEM); //adduri用来注册URI的 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); // /* 为任意字符 } /** * 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; 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 //重写 public boolean onCreate() { mHelper = NotesDatabaseHelper.getInstance(getContext()); return true; } @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)) { //现有的URI与注册的URI进行匹配 case URI_NOTE: c = db.query(TABLE.NOTE, projection, selection, selectionArgs, null, null, sortOrder); //查询note表 break; case URI_NOTE_ITEM: id = uri.getPathSegments().get(1); //将URI分割，1代表的是id c = db.query(TABLE.NOTE, projection, NoteColumns.ID + "=" + id + parseSelection(selection), selectionArgs, null, null, sortOrder); //查询id break; case URI_DATA: c = db.query(TABLE.DATA, projection, selection, selectionArgs, null, null, sortOrder); //查询data数据表 break; case URI_DATA_ITEM: id = uri.getPathSegments().get(1); //将URI分割，获得id c = db.query(TABLE.DATA, projection, DataColumns.ID + "=" + id + parseSelection(selection), selectionArgs, null, null, sortOrder); //查询该id break; case URI_SEARCH: case URI_SEARCH_SUGGEST: if (sortOrder != null || projection != null) { //两者其一不为空 throw new IllegalArgumentException( "do not specify sortOrder, selection, selectionArgs, or projection" + "with this query"); //抛出异常 } String searchString = null; if (mMatcher.match(uri) == URI_SEARCH_SUGGEST) { //路径是否匹配 if (uri.getPathSegments().size() > 1) { //截取的路径list表的大小 searchString = uri.getPathSegments().get(1); } } else { searchString = uri.getQueryParameter("pattern"); } if (TextUtils.isEmpty(searchString)) { //是否为空 return null; } try { searchString = String.format("%%%s%%", searchString); //字符串的加工 c = db.rawQuery(NOTES_SNIPPET_SEARCH_QUERY, new String[] { searchString }); //sql语句查询，并替换 } catch (IllegalStateException ex) { Log.e(TAG, "got exception: " + ex.toString()); //记录日志 } break; default: throw new IllegalArgumentException("Unknown URI " + uri); //抛出异常 } if (c != null) { c.setNotificationUri(getContext().getContentResolver(), uri); } return c; } @Override public Uri insert(Uri uri, ContentValues values) { //重写插入 SQLiteDatabase db = mHelper.getWritableDatabase(); //获得数据库对象 long dataId = 0, noteId = 0, insertedId = 0; switch (mMatcher.match(uri)) { //URI路径是否匹配 case URI_NOTE: //note等于匹配码 insertedId = noteId = db.insert(TABLE.NOTE, null, values); //插入 break; case URI_DATA: //等于data的匹配码 if (values.containsKey(DataColumns.NOTE_ID)) { noteId = values.getAsLong(DataColumns.NOTE_ID); } else { Log.d(TAG, "Wrong data format without note id:" + values.toString()); //记录日志 } 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); } @Override public int delete(Uri uri, String selection, String[] selectionArgs) { //重写delete方法 int count = 0; String id = null; SQLiteDatabase db = mHelper.getWritableDatabase(); //获取数据库对象 boolean deleteData = false; switch (mMatcher.match(uri)) { //获得匹配码 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); //删除 break; case URI_DATA: count = db.delete(TABLE.DATA, selection, selectionArgs); //删除data deleteData = true; break; case URI_DATA_ITEM: id = uri.getPathSegments().get(1); count = db.delete(TABLE.DATA, DataColumns.ID + "=" + id + parseSelection(selection), selectionArgs); //删除dataitem deleteData = true; break; default: throw new IllegalArgumentException("Unknown URI " + uri); //抛出异常 } if (count > 0) { if (deleteData) { getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null); } getContext().getContentResolver().notifyChange(uri, null); } return count; } @Override public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) { //重写更新方法 int count = 0; String id = null; SQLiteDatabase db = mHelper.getWritableDatabase(); //获得数据库对象 boolean updateData = false; switch (mMatcher.match(uri)) { case URI_NOTE: //获得查询匹配码 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 //note的更新 + parseSelection(selection), selectionArgs); break; case URI_DATA: count = db.update(TABLE.DATA, values, selection, selectionArgs); //data的更新 updateData = true; break; case URI_DATA_ITEM: id = uri.getPathSegments().get(1); count = db.update(TABLE.DATA, values, DataColumns.ID + "=" + id //dataitem的更新 + parseSelection(selection), selectionArgs); updateData = true; break; default: throw new IllegalArgumentException("Unknown URI " + uri); //抛出没有参数的异常 } 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); //容量为120 sql.append("UPDATE "); //拼接更新 sql.append(TABLE.NOTE); //note数据列 sql.append(" SET "); sql.append(NoteColumns.VERSION); sql.append("=" + NoteColumns.VERSION + "+1 "); if (id > 0 || !TextUtils.isEmpty(selection)) { sql.append(" WHERE "); //位置 } 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 public String getType(Uri uri) { // TODO Auto-generated method stub return null; } }