/* * 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.gtask.data; import android.content.ContentResolver; import android.content.ContentUris; import android.content.ContentValues; import android.content.Context; import android.database.Cursor; import android.net.Uri; import android.util.Log; import net.micode.notes.data.Notes; import net.micode.notes.data.Notes.DataColumns; import net.micode.notes.data.Notes.DataConstants; import net.micode.notes.data.Notes.NoteColumns; import net.micode.notes.data.NotesDatabaseHelper.TABLE; import net.micode.notes.gtask.exception.ActionFailureException; import org.json.JSONException; import org.json.JSONObject; public class SqlData { //TAG:用于日志记录,方便调试和问题追踪 private static final String TAG = SqlData.class.getSimpleName(); //INVALID_ID:作为无效 ID 的标识,用于初始化和错误处理 private static final int INVALID_ID = -99999; // public static final String[] PROJECTION_DATA = new String[] { DataColumns.ID, DataColumns.MIME_TYPE, DataColumns.CONTENT, DataColumns.DATA1, DataColumns.DATA3 }; public static final int DATA_ID_COLUMN = 0; public static final int DATA_MIME_TYPE_COLUMN = 1; public static final int DATA_CONTENT_COLUMN = 2; public static final int DATA_CONTENT_DATA_1_COLUMN = 3; public static final int DATA_CONTENT_DATA_3_COLUMN = 4; private ContentResolver mContentResolver; private boolean mIsCreate; private long mDataId; private String mDataMimeType; private String mDataContent; private long mDataContentData1; private String mDataContentData3; private ContentValues mDiffDataValues; /** * 1.作用:构造函数 * 2.初始化 ContentResolver: * 从传入的 Context 获取 ContentResolver 实例 * 用于后续与 ContentProvider 交互 */ public SqlData(Context context) { mContentResolver = context.getContentResolver(); mIsCreate = true; mDataId = INVALID_ID; mDataMimeType = DataConstants.NOTE; mDataContent = ""; mDataContentData1 = 0; mDataContentData3 = ""; mDiffDataValues = new ContentValues(); } /** * 1.作用:构造函数(两个参数) * 2.初始化 ContentResolver: * 从传入的 Context 获取 ContentResolver 实例 * 用于后续与 ContentProvider 交互 */ public SqlData(Context context, Cursor c) { mContentResolver = context.getContentResolver(); mIsCreate = false; loadFromCursor(c); mDiffDataValues = new ContentValues(); } /** 1.作用:从Cursor中加载数据到当前对象 * 2.方法名:loadFromCursor * 3.参数: * Cursor c:包含数据的Cursor对象 * 4.返回类型:void * 5.功能: * 将Cursor中的数据映射到SqlData对象的成员变量 * 使用预定义的列索引常量定位数据 * 支持从数据库查询结果中初始化对象 */ private void loadFromCursor(Cursor c) { mDataId = c.getLong(DATA_ID_COLUMN); mDataMimeType = c.getString(DATA_MIME_TYPE_COLUMN); mDataContent = c.getString(DATA_CONTENT_COLUMN); mDataContentData1 = c.getLong(DATA_CONTENT_DATA_1_COLUMN); mDataContentData3 = c.getString(DATA_CONTENT_DATA_3_COLUMN); } /** * 1.作用:从JSONObject设置数据到当前对象 * 2.方法名:setContent * 3.参数: * JSONObject js:包含数据的JSON对象 * 4.返回类型:void * 5.功能: * 从JSON对象解析数据并设置到SqlData对象 * 自动检测数据变化并记录差异 * 支持默认值处理和类型转换 */ public void setContent(JSONObject js) throws JSONException { long dataId = js.has(DataColumns.ID) ? js.getLong(DataColumns.ID) : INVALID_ID; if (mIsCreate || mDataId != dataId) { mDiffDataValues.put(DataColumns.ID, dataId); } mDataId = dataId; String dataMimeType = js.has(DataColumns.MIME_TYPE) ? js.getString(DataColumns.MIME_TYPE) : DataConstants.NOTE; if (mIsCreate || !mDataMimeType.equals(dataMimeType)) { mDiffDataValues.put(DataColumns.MIME_TYPE, dataMimeType); } mDataMimeType = dataMimeType; String dataContent = js.has(DataColumns.CONTENT) ? js.getString(DataColumns.CONTENT) : ""; if (mIsCreate || !mDataContent.equals(dataContent)) { mDiffDataValues.put(DataColumns.CONTENT, dataContent); } mDataContent = dataContent; long dataContentData1 = js.has(DataColumns.DATA1) ? js.getLong(DataColumns.DATA1) : 0; if (mIsCreate || mDataContentData1 != dataContentData1) { mDiffDataValues.put(DataColumns.DATA1, dataContentData1); } mDataContentData1 = dataContentData1; String dataContentData3 = js.has(DataColumns.DATA3) ? js.getString(DataColumns.DATA3) : ""; if (mIsCreate || !mDataContentData3.equals(dataContentData3)) { mDiffDataValues.put(DataColumns.DATA3, dataContentData3); } mDataContentData3 = dataContentData3; } /** 1.作用:将当前对象数据导出为JSON对象 * 2.方法名:getContent * 3.参数:无 * 4.返回类型:JSONObject * 5.功能: * 将SqlData对象的成员变量转换为JSON格式 * 支持数据序列化和跨组件传递 * 用于数据导出、网络传输和持久化存储 * */ public JSONObject getContent() throws JSONException { if (mIsCreate) { Log.e(TAG, "it seems that we haven't created this in database yet"); return null; } JSONObject js = new JSONObject(); js.put(DataColumns.ID, mDataId); js.put(DataColumns.MIME_TYPE, mDataMimeType); js.put(DataColumns.CONTENT, mDataContent); js.put(DataColumns.DATA1, mDataContentData1); js.put(DataColumns.DATA3, mDataContentData3); return js; } /** * 1.作用:将数据变更提交到数据库 * 2.方法名:commit * 3.参数: * long noteId:关联的笔记ID * boolean validateVersion:是否验证版本号 * long version:用于验证的版本号 * 4.返回类型:void * 5.功能: * 根据对象状态执行插入或更新操作 * 支持版本验证,防止并发修改冲突 * 自动清除差异值跟踪容器 * 更新对象状态为已创建 * */ public void commit(long noteId, boolean validateVersion, long version) { if (mIsCreate) { if (mDataId == INVALID_ID && mDiffDataValues.containsKey(DataColumns.ID)) { mDiffDataValues.remove(DataColumns.ID); } mDiffDataValues.put(DataColumns.NOTE_ID, noteId); Uri uri = mContentResolver.insert(Notes.CONTENT_DATA_URI, mDiffDataValues); try { mDataId = Long.valueOf(uri.getPathSegments().get(1)); } catch (NumberFormatException e) { Log.e(TAG, "Get note id error :" + e.toString()); throw new ActionFailureException("create note failed"); } } else { if (mDiffDataValues.size() > 0) { int result = 0; if (!validateVersion) { result = mContentResolver.update(ContentUris.withAppendedId( Notes.CONTENT_DATA_URI, mDataId), mDiffDataValues, null, null); } else { result = mContentResolver.update(ContentUris.withAppendedId( Notes.CONTENT_DATA_URI, mDataId), mDiffDataValues, " ? in (SELECT " + NoteColumns.ID + " FROM " + TABLE.NOTE + " WHERE " + NoteColumns.VERSION + "=?)", new String[] { String.valueOf(noteId), String.valueOf(version) }); } if (result == 0) { Log.w(TAG, "there is no update. maybe user updates note when syncing"); } } } mDiffDataValues.clear(); mIsCreate = false; } public long getId() { return mDataId; } }