diff --git a/app/src/main/java/net/micode/notes/gtask/data/SqlData.java b/app/src/main/java/net/micode/notes/gtask/data/SqlData.java index d3ec3be..7ecbebc 100644 --- a/app/src/main/java/net/micode/notes/gtask/data/SqlData.java +++ b/app/src/main/java/net/micode/notes/gtask/data/SqlData.java @@ -35,75 +35,75 @@ import org.json.JSONException; import org.json.JSONObject; +// 数据库数据操作类，处理GTask相关数据的SQL操作 public class SqlData { + // 日志标签，使用类名 private static final String TAG = SqlData.class.getSimpleName(); - + // 无效ID常量 private static final int INVALID_ID = -99999; + // 数据查询投影数组，定义查询返回的列 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; - + // 投影数组中各列的索引 + public static final int DATA_ID_COLUMN = 0; // ID列索引 + public static final int DATA_MIME_TYPE_COLUMN = 1; // MIME类型列索引 + public static final int DATA_CONTENT_COLUMN = 2; // 内容列索引 + public static final int DATA_CONTENT_DATA_1_COLUMN = 3;// 数据1列索引 + public static final int DATA_CONTENT_DATA_3_COLUMN = 4;// 数据3列索引 + + // 成员变量 + private ContentResolver mContentResolver; // 内容解析器，用于操作ContentProvider + private boolean mIsCreate; // 标记是否为新建数据 + 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1 + private String mDataContentData3; // 数据3 + private ContentValues mDiffDataValues; // 变更的数据值 + + // 构造方法，初始化数据对象 public SqlData(Context context) { - mContentResolver = context.getContentResolver(); - mIsCreate = true; - mDataId = INVALID_ID; - mDataMimeType = DataConstants.NOTE; - mDataContent = ""; - mDataContentData1 = 0; - mDataContentData3 = ""; - mDiffDataValues = new ContentValues(); + mContentResolver = context.getContentResolver(); // 获取内容解析器 + mIsCreate = true; // 标记为新建状态 + mDataId = INVALID_ID; // 设置无效ID + mDataMimeType = DataConstants.NOTE; // 默认MIME类型为笔记 + mDataContent = ""; // 初始化内容为空 + mDataContentData1 = 0; // 初始化数据1为0 + mDataContentData3 = ""; // 初始化数据3为空 + mDiffDataValues = new ContentValues(); // 初始化变更值集合 } + // 从Cursor构造数据对象，用于从数据库查询结果创建对象 public SqlData(Context context, Cursor c) { - mContentResolver = context.getContentResolver(); - mIsCreate = false; - loadFromCursor(c); - mDiffDataValues = new ContentValues(); + mContentResolver = context.getContentResolver(); // 获取内容解析器 + mIsCreate = false; // 标记为非新建状态 + loadFromCursor(c); // 从Cursor加载数据 + mDiffDataValues = new ContentValues(); // 初始化变更值集合 } + // 从Cursor加载数据到对象 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); + mDataId = c.getLong(DATA_ID_COLUMN); // 获取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); // 获取数据1 + mDataContentData3 = c.getString(DATA_CONTENT_DATA_3_COLUMN); // 获取数据3 } + // 根据JSON对象设置数据内容 public void setContent(JSONObject js) throws JSONException { + // 处理ID long dataId = js.has(DataColumns.ID) ? js.getLong(DataColumns.ID) : INVALID_ID; if (mIsCreate || mDataId != dataId) { mDiffDataValues.put(DataColumns.ID, dataId); } mDataId = dataId; + // 处理MIME类型 String dataMimeType = js.has(DataColumns.MIME_TYPE) ? js.getString(DataColumns.MIME_TYPE) : DataConstants.NOTE; if (mIsCreate || !mDataMimeType.equals(dataMimeType)) { @@ -111,18 +111,21 @@ public class SqlData { } mDataMimeType = dataMimeType; + // 处理内容 String dataContent = js.has(DataColumns.CONTENT) ? js.getString(DataColumns.CONTENT) : ""; if (mIsCreate || !mDataContent.equals(dataContent)) { mDiffDataValues.put(DataColumns.CONTENT, dataContent); } mDataContent = dataContent; + // 处理数据1 long dataContentData1 = js.has(DataColumns.DATA1) ? js.getLong(DataColumns.DATA1) : 0; if (mIsCreate || mDataContentData1 != dataContentData1) { mDiffDataValues.put(DataColumns.DATA1, dataContentData1); } mDataContentData1 = dataContentData1; + // 处理数据3 String dataContentData3 = js.has(DataColumns.DATA3) ? js.getString(DataColumns.DATA3) : ""; if (mIsCreate || !mDataContentData3.equals(dataContentData3)) { mDiffDataValues.put(DataColumns.DATA3, dataContentData3); @@ -130,11 +133,13 @@ public class SqlData { mDataContentData3 = dataContentData3; } + // 获取数据的JSON表示 public JSONObject getContent() throws JSONException { if (mIsCreate) { Log.e(TAG, "it seems that we haven't created this in database yet"); return null; } + // 创建并填充JSON对象 JSONObject js = new JSONObject(); js.put(DataColumns.ID, mDataId); js.put(DataColumns.MIME_TYPE, mDataMimeType); @@ -144,30 +149,36 @@ public class SqlData { return js; } + // 提交数据到数据库 public void commit(long noteId, boolean validateVersion, long version) { - if (mIsCreate) { + // 处理新建数据 if (mDataId == INVALID_ID && mDiffDataValues.containsKey(DataColumns.ID)) { mDiffDataValues.remove(DataColumns.ID); } - + // 设置所属笔记ID mDiffDataValues.put(DataColumns.NOTE_ID, noteId); + // 插入数据到ContentProvider Uri uri = mContentResolver.insert(Notes.CONTENT_DATA_URI, mDiffDataValues); try { + // 从返回的Uri中获取数据ID 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 { + // 处理已存在数据的更新 if (mDiffDataValues.size() > 0) { int result = 0; if (!validateVersion) { + // 不验证版本的更新 result = mContentResolver.update(ContentUris.withAppendedId( Notes.CONTENT_DATA_URI, mDataId), mDiffDataValues, null, null); } else { + // 验证版本的更新，防止并发冲突 result = mContentResolver.update(ContentUris.withAppendedId( - Notes.CONTENT_DATA_URI, mDataId), mDiffDataValues, + Notes.CONTENT_DATA_URI, mDataId), mDiffDataValues, " ? in (SELECT " + NoteColumns.ID + " FROM " + TABLE.NOTE + " WHERE " + NoteColumns.VERSION + "=?)", new String[] { String.valueOf(noteId), String.valueOf(version) @@ -178,12 +189,13 @@ public class SqlData { } } } - + // 清空变更值，标记为非新建状态 mDiffDataValues.clear(); mIsCreate = false; } + // 获取数据ID public long getId() { return mDataId; } -} +} \ No newline at end of file