/* * 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 { private static final String TAG = SqlData.class.getSimpleName(); // 用于日志记录的标签 private static final int INVALID_ID = -99999; // 无效ID常量 // 数据库列的投影 public static final String[] PROJECTION_DATA = new String[] { DataColumns.ID, DataColumns.MIME_TYPE, DataColumns.CONTENT, DataColumns.DATA1, DataColumns.DATA3 }; // 数据库列索引 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; // 内容解析器,用于与内容提供者交互 private boolean mIsCreate; // 标识是否为新创建的数据 private long mDataId; // 数据ID private String mDataMimeType; // 数据MIME类型 private String mDataContent; // 数据内容 private long mDataContentData1; // 数据内容的附加信息1 private String mDataContentData3; // 数据内容的附加信息3 private ContentValues mDiffDataValues; // 存储数据变化的内容值 // 构造函数,初始化新数据 public SqlData(Context context) { mContentResolver = context.getContentResolver(); // 获取内容解析器 mIsCreate = true; // 标记为新创建 mDataId = INVALID_ID; // 初始化ID为无效值 mDataMimeType = DataConstants.NOTE; // 默认MIME类型为NOTE mDataContent = ""; // 初始化内容为空 mDataContentData1 = 0; // 初始化附加信息1为0 mDataContentData3 = ""; // 初始化附加信息3为空 mDiffDataValues = new ContentValues(); // 初始化内容值对象 } // 构造函数,初始化已有数据 public SqlData(Context context, Cursor c) { mContentResolver = context.getContentResolver(); // 获取内容解析器 mIsCreate = false; // 标记为已有数据 loadFromCursor(c); // 从Cursor加载数据 mDiffDataValues = new ContentValues(); // 初始化内容值对象 } // 从Cursor加载数据 private void loadFromCursor(Cursor c) { mDataId = c.getLong(DATA_ID_COLUMN); // 获取数据ID mDataMimeType = c.getString(DATA_MIME_TYPE_COLUMN); // 获取MIME类型 mDataContent = c.getString(DATA_CONTENT_COLUMN); // 获取内容 mDataContentData1 = c.getLong(DATA_CONTENT_DATA_1_COLUMN); // 获取附加信息1 mDataContentData3 = c.getString(DATA_CONTENT_DATA_3_COLUMN); // 获取附加信息3 } // 设置内容,从JSON对象中提取数据 public void setContent(JSONObject js) throws JSONException { long dataId = js.has(DataColumns.ID) ? js.getLong(DataColumns.ID) : INVALID_ID; // 获取ID if (mIsCreate || mDataId != dataId) { mDiffDataValues.put(DataColumns.ID, dataId); // 更新ID } mDataId = dataId; String dataMimeType = js.has(DataColumns.MIME_TYPE) ? js.getString(DataColumns.MIME_TYPE) : DataConstants.NOTE; // 获取MIME类型 if (mIsCreate || !mDataMimeType.equals(dataMimeType)) { mDiffDataValues.put(DataColumns.MIME_TYPE, dataMimeType); // 更新MIME类型 } mDataMimeType = dataMimeType; String dataContent = js.has(DataColumns.CONTENT) ? js.getString(DataColumns.CONTENT) : ""; // 获取内容 if (mIsCreate || !mDataContent.equals(dataContent)) { mDiffDataValues.put(DataColumns.CONTENT, dataContent); // 更新内容 } mDataContent = dataContent; long dataContentData1 = js.has(DataColumns.DATA1) ? js.getLong(DataColumns.DATA1) : 0; // 获取附加信息1 if (mIsCreate || mDataContentData1 != dataContentData1) { mDiffDataValues.put(DataColumns.DATA1, dataContentData1); // 更新附加信息1 } mDataContentData1 = dataContentData1; String dataContentData3 = js.has(DataColumns.DATA3) ? js.getString(DataColumns.DATA3) : ""; // 获取附加信息3 if (mIsCreate || !mDataContentData3.equals(dataContentData3)) { mDiffDataValues.put(DataColumns.DATA3, dataContentData3); // 更新附加信息3 } mDataContentData3 = dataContentData3; } // 获取内容,返回JSON对象 public JSONObject getContent() throws JSONException { if (mIsCreate) { Log.e(TAG, "it seems that we haven't created this in database yet"); // 如果未创建,记录错误 return null; } JSONObject js = new JSONObject(); // 创建JSON对象 js.put(DataColumns.ID, mDataId); // 添加ID js.put(DataColumns.MIME_TYPE, mDataMimeType); // 添加MIME类型 js.put(DataColumns.CONTENT, mDataContent); // 添加内容 js.put(DataColumns.DATA1, mDataContentData1); // 添加附加信息1 js.put(DataColumns.DATA3, mDataContentData3); // 添加附加信息3 return js; // 返回JSON对象 } // 提交数据到数据库 public void commit(long noteId, boolean validateVersion, long version) { if (mIsCreate) { if (mDataId == INVALID_ID && mDiffDataValues.containsKey(DataColumns.ID)) { mDiffDataValues.remove(DataColumns.ID); // 如果ID无效,移除ID } mDiffDataValues.put(DataColumns.NOTE_ID, noteId); // 添加笔记ID Uri uri = mContentResolver.insert(Notes.CONTENT_DATA_URI, mDiffDataValues); // 插入数据 try { mDataId = Long.valueOf(uri.getPathSegments().get(1)); // 获取新插入数据的ID } catch (NumberFormatException e) { Log.e(TAG, "Get note id error :" + e.toString()); // 记录错误 throw new ActionFailureException("create note failed"); // 抛出异常 } } else { if (mDiffDataValues.size() > 0) { int result = 0; if (!validateVersion) { result = mContentResolver.update(ContentUris.withAppendedId( Notes.CONTENT_DATA_URI, mDataId), mDiffDataValues, null, null); // 更新数据 } 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) }); // 带版本验证的更新 } if (result == 0) { Log.w(TAG, "there is no update. maybe user updates note when syncing"); // 记录警告 } } } mDiffDataValues.clear(); // 清空差异数据 mIsCreate = false; // 标记为非创建状态 } // 获取数据ID public long getId() { return mDataId; // 返回数据ID } }