diff --git a/SqlData.java b/SqlData.java new file mode 100644 index 0000000..fb8aa23 --- /dev/null +++ b/SqlData.java @@ -0,0 +1,197 @@ +/* + * 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; + +// SqlData 类用于处理与数据库相关的操作，特别是与笔记数据相关的操作。 +public class SqlData { + // 类的标签，用于日志记录。 + private static final String TAG = SqlData.class.getSimpleName(); + + // 一个无效的ID值，用于初始化或表示没有ID。 + private static final int INVALID_ID = -99999; + + // 数据库查询时使用的列投影。 + public static final String[] PROJECTION_DATA = new String[] { + DataColumns.ID, DataColumns.MIME_TYPE, DataColumns.CONTENT, DataColumns.DATA1, + DataColumns.DATA3 + }; + + // 列索引常量。 + 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; + + // 数据库操作相关的成员变量。 + private ContentResolver mContentResolver; + private boolean mIsCreate; + private long mDataId; + private String mDataMimeType; + private String mDataContent; + private long mDataContentData1; + private String mDataContentData3; + private ContentValues mDiffDataValues; + + // SqlData 的构造函数，用于创建一个新的SqlData实例。 + public SqlData(Context context) { + mContentResolver = context.getContentResolver(); + mIsCreate = true; + mDataId = INVALID_ID; + mDataMimeType = DataConstants.NOTE; + mDataContent = ""; + mDataContentData1 = 0; + mDataContentData3 = ""; + mDiffDataValues = new ContentValues(); + } + + // SqlData 的另一个构造函数，用于从数据库游标中加载数据。 + public SqlData(Context context, Cursor c) { + mContentResolver = context.getContentResolver(); + mIsCreate = false; + loadFromCursor(c); + mDiffDataValues = new ContentValues(); + } + + // 从游标中加载数据的方法。 + 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); + } + + // 从JSONObject中设置内容的方法。 + public void setContent(JSONObject js) throws JSONException { + long dataId = js.has(DataColumns.ID) ? js.getLong(DataColumns.ID) : INVALID_ID; + // 如果是新建或者ID不匹配，则更新ID。 + if (mIsCreate || mDataId != dataId) { + mDiffDataValues.put(DataColumns.ID, dataId); + } + mDataId = dataId; + + // 设置MIME类型，如果发生变化则更新。 + 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; + + // 设置内容，如果发生变化则更新。 + String dataContent = js.has(DataColumns.CONTENT) ? js.getString(DataColumns.CONTENT) : ""; + if (mIsCreate || !mDataContent.equals(dataContent)) { + mDiffDataValues.put(DataColumns.CONTENT, dataContent); + } + mDataContent = dataContent; + + // 设置DATA1，如果发生变化则更新。 + long dataContentData1 = js.has(DataColumns.DATA1) ? js.getLong(DataColumns.DATA1) : 0; + if (mIsCreate || mDataContentData1 != dataContentData1) { + mDiffDataValues.put(DataColumns.DATA1, dataContentData1); + } + mDataContentData1 = dataContentData1; + + // 设置DATA3，如果发生变化则更新。 + String dataContentData3 = js.has(DataColumns.DATA3) ? js.getString(DataColumns.DATA3) : ""; + if (mIsCreate || !mDataContentData3.equals(dataContentData3)) { + mDiffDataValues.put(DataColumns.DATA3, dataContentData3); + } + mDataContentData3 = dataContentData3; + } + + // 获取内容并返回JSONObject的方法。 + 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; + } + + // 提交数据到数据库的方法。 + public void commit(long noteId, boolean validateVersion, long version) { + if (mIsCreate) { + // 如果是新建数据，插入到数据库中。 + 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 { + // 如果是更新数据，根据版本号更新数据库中的记录。 + 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"); + } + } + } + + // 清除差异值并标记为非新建状态。 + mDiffDataValues.clear(); + mIsCreate = false; + } + + // 获取数据ID的方法。 + public long getId() { + return mDataId; + } +} \ No newline at end of file