|
|
package net.micode.notes.data; // 定义包名
|
|
|
import android.app.SearchManager; // 搜索管理器，用于处理搜索建议等
|
|
|
import android.content.ContentProvider; // Android内容提供者基类
|
|
|
import android.content.ContentUris; // 用于操作URI，如添加ID到URI中
|
|
|
import android.content.ContentValues; // 用于存储数据的键值对，便于数据库操作
|
|
|
import android.content.Intent; // 用于应用程序之间传递数据的意图
|
|
|
import android.content.UriMatcher; // 用于匹配URI
|
|
|
import android.database.Cursor; // 用于数据库查询结果集的迭代
|
|
|
import android.database.sqlite.SQLiteDatabase; // 用于执行SQL语句和进行数据库操作
|
|
|
import android.net.Uri; // 用于表示URI的类
|
|
|
import android.text.TextUtils; // 文本操作工具类
|
|
|
import android.util.Log; // 用于日志输出
|
|
|
import net.micode.notes.R; // 资源类
|
|
|
import net.micode.notes.data.Notes.DataColumns; // 数据表列常量
|
|
|
import net.micode.notes.data.Notes.NoteColumns; // 笔记表列常量
|
|
|
import net.micode.notes.data.NotesDatabaseHelper.TABLE; // 数据表名称常量
|
|
|
|
|
|
// NotesProvider类继承自ContentProvider，用于提供数据共享接口
|
|
|
public class NotesProvider extends ContentProvider {
|
|
|
// UriMatcher用于匹配URI
|
|
|
private static final UriMatcher mMatcher;
|
|
|
|
|
|
private NotesDatabaseHelper mHelper; // 数据库帮助类实例
|
|
|
|
|
|
private static final String TAG = "NotesProvider"; // 日志标签
|
|
|
|
|
|
// 定义匹配URI的常量
|
|
|
private static final int URI_NOTE = 1;//用于标识笔记资源
|
|
|
private static final int URI_NOTE_ITEM = 2;//用于标识单个笔记资源
|
|
|
private static final int URI_DATA = 3;//用于标识数据资源
|
|
|
private static final int URI_DATA_ITEM = 4;//用于标识单个数据资源
|
|
|
private static final int URI_SEARCH = 5;//搜索功能
|
|
|
private static final int URI_SEARCH_SUGGEST = 6;//用于标识搜索功能
|
|
|
|
|
|
static {
|
|
|
// 创建UriMatcher时，调用UriMatcher(UriMatcher.NO_MATCH)表示不匹配任何路径的返回码
|
|
|
mMatcher = new UriMatcher(UriMatcher.NO_MATCH);
|
|
|
// 把需要匹配URI路径全部给注册上
|
|
|
mMatcher.addURI(Notes.AUTHORITY, "note", URI_NOTE);//笔记表
|
|
|
mMatcher.addURI(Notes.AUTHORITY, "note/#", URI_NOTE_ITEM);//笔记表中的某条记录
|
|
|
mMatcher.addURI(Notes.AUTHORITY, "data", URI_DATA);//数据表
|
|
|
mMatcher.addURI(Notes.AUTHORITY, "data/#", URI_DATA_ITEM);//数据表中的某条数据
|
|
|
mMatcher.addURI(Notes.AUTHORITY, "search", URI_SEARCH);//搜索
|
|
|
mMatcher.addURI(Notes.AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY, URI_SEARCH_SUGGEST);//搜索建议
|
|
|
mMatcher.addURI(Notes.AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY + "/*", URI_SEARCH_SUGGEST);//搜索建议
|
|
|
}
|
|
|
|
|
|
// 声明搜索结果的投影
|
|
|
private static final String NOTES_SEARCH_PROJECTION = NoteColumns.ID + ","//笔记ID
|
|
|
+ NoteColumns.ID + " AS " + SearchManager.SUGGEST_COLUMN_INTENT_EXTRA_DATA + ","//意图数据
|
|
|
+ "TRIM(REPLACE(" + NoteColumns.SNIPPET + ", x'0A','')) AS " + SearchManager.SUGGEST_COLUMN_TEXT_1 + ","//笔记摘要
|
|
|
+ "TRIM(REPLACE(" + NoteColumns.SNIPPET + ", x'0A','')) AS " + SearchManager.SUGGEST_COLUMN_TEXT_2 + ","//
|
|
|
+ R.drawable.search_result + " AS " + SearchManager.SUGGEST_COLUMN_ICON_1 + ","//搜索结构图标
|
|
|
+ "'" + Intent.ACTION_VIEW + "' AS " + SearchManager.SUGGEST_COLUMN_INTENT_ACTION + ","//意图动作
|
|
|
+ "'" + Notes.TextNote.CONTENT_TYPE + "' AS " + SearchManager.SUGGEST_COLUMN_INTENT_DATA;//意图数据类型
|
|
|
|
|
|
// 声明搜索查询
|
|
|
private static String NOTES_SNIPPET_SEARCH_QUERY = "SELECT " + NOTES_SEARCH_PROJECTION//查询语句
|
|
|
+ " FROM " + TABLE.NOTE//表名
|
|
|
+ " WHERE " + NoteColumns.SNIPPET + " LIKE ?"//查询条件
|
|
|
+ " AND " + NoteColumns.PARENT_ID + "<>" + Notes.ID_TRASH_FOLER//排除回收站
|
|
|
+ " AND " + NoteColumns.TYPE + "=" + Notes.TYPE_NOTE;//笔记类型
|
|
|
|
|
|
@Override
|
|
|
// Context只有在onCreate()中才被初始化，对mHelper进行实例化
|
|
|
public boolean onCreate() {
|
|
|
mHelper = NotesDatabaseHelper.getInstance(getContext());
|
|
|
return true;
|
|
|
}
|
|
|
|
|
|
@Override
|
|
|
// 查询uri在数据库中对应的位置
|
|
|
public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs,
|
|
|
String sortOrder) {
|
|
|
Cursor c = null;
|
|
|
// 获取可读数据库
|
|
|
SQLiteDatabase db = mHelper.getReadableDatabase();
|
|
|
String id = null;
|
|
|
// 匹配查找uri
|
|
|
switch (mMatcher.match(uri)) {
|
|
|
// 对于不同的匹配值，在数据库中查找相应的条目
|
|
|
case URI_NOTE:
|
|
|
c = db.query(TABLE.NOTE, projection, selection, selectionArgs, null, null,
|
|
|
sortOrder);
|
|
|
break;
|
|
|
case URI_NOTE_ITEM:
|
|
|
id = uri.getPathSegments().get(1);
|
|
|
c = db.query(TABLE.NOTE, projection, NoteColumns.ID + "=" + id
|
|
|
+ parseSelection(selection), selectionArgs, null, null, sortOrder);
|
|
|
break;
|
|
|
case URI_DATA:
|
|
|
c = db.query(TABLE.DATA, projection, selection, selectionArgs, null, null,
|
|
|
sortOrder);
|
|
|
break;
|
|
|
case URI_DATA_ITEM:
|
|
|
id = uri.getPathSegments().get(1);
|
|
|
c = db.query(TABLE.DATA, projection, DataColumns.ID + "=" + id
|
|
|
+ parseSelection(selection), selectionArgs, null, null, sortOrder);
|
|
|
break;
|
|
|
case URI_SEARCH:
|
|
|
case URI_SEARCH_SUGGEST:
|
|
|
if (sortOrder != null || projection != null) {
|
|
|
// 不合法的参数异常
|
|
|
throw new IllegalArgumentException(
|
|
|
"do not specify sortOrder, selection, selectionArgs, or projection" + "with this query");
|
|
|
}
|
|
|
|
|
|
String searchString = null;
|
|
|
if (mMatcher.match(uri) == URI_SEARCH_SUGGEST) {
|
|
|
if (uri.getPathSegments().size() > 1) {
|
|
|
// getPathSegments()方法得到一个String的List，
|
|
|
// 在uri.getPathSegments().get(1)为第2个元素
|
|
|
searchString = uri.getPathSegments().get(1);
|
|
|
}
|
|
|
} else {
|
|
|
searchString = uri.getQueryParameter("pattern");
|
|
|
}
|
|
|
|
|
|
if (TextUtils.isEmpty(searchString)) {
|
|
|
return null;
|
|
|
}
|
|
|
|
|
|
try {
|
|
|
searchString = String.format("%%%s%%", searchString);
|
|
|
c = db.rawQuery(NOTES_SNIPPET_SEARCH_QUERY,
|
|
|
new String[] { searchString });
|
|
|
} catch (IllegalStateException ex) {
|
|
|
Log.e(TAG, "got exception: " + ex.toString());
|
|
|
}
|
|
|
break;
|
|
|
default:
|
|
|
// 抛出异常
|
|
|
throw new IllegalArgumentException("Unknown URI " + uri);
|
|
|
}
|
|
|
if (c != null) {
|
|
|
c.setNotificationUri(getContext().getContentResolver(), uri);
|
|
|
}
|
|
|
return c;
|
|
|
}
|
|
|
|
|
|
@Override
|
|
|
// 插入一个uri
|
|
|
public Uri insert(Uri uri, ContentValues values) {
|
|
|
// 获得可写的数据库
|
|
|
SQLiteDatabase db = mHelper.getWritableDatabase();
|
|
|
long dataId = 0, noteId = 0, insertedId = 0;
|
|
|
switch (mMatcher.match(uri)) {
|
|
|
// 新增一个条目
|
|
|
case URI_NOTE:
|
|
|
insertedId = noteId = db.insert(TABLE.NOTE, null, values);
|
|
|
break;
|
|
|
// 如果存在，查找NOTE_ID
|
|
|
case URI_DATA:
|
|
|
if (values.containsKey(DataColumns.NOTE_ID)) {
|
|
|
noteId = values.getAsLong(DataColumns.NOTE_ID);
|
|
|
} else {
|
|
|
Log.d(TAG, "Wrong data format without note id:" + values.toString());
|
|
|
}
|
|
|
insertedId = dataId = db.insert(TABLE.DATA, null, values);
|
|
|
break;
|
|
|
default:
|
|
|
throw new IllegalArgumentException("Unknown URI " + uri);
|
|
|
}
|
|
|
// Notify the note uri
|
|
|
// notifyChange获得一个ContextResolver对象并且更新里面的内容
|
|
|
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);
|
|
|
}
|
|
|
|
|
|
// 返回插入的uri的路径
|
|
|
return ContentUris.withAppendedId(uri, insertedId);
|
|
|
}
|
|
|
|
|
|
@Override
|
|
|
// 删除一个uri
|
|
|
public int delete(Uri uri, String selection, String[] selectionArgs) {
|
|
|
// Uri代表要操作的数据，Android上可用的每种资源 -包括 图像、视频片段、音频资源等都可以用Uri来表示。
|
|
|
int count = 0;
|
|
|
String id = null;
|
|
|
// 获得可写的数据库
|
|
|
SQLiteDatabase db = mHelper.getWritableDatabase();
|
|
|
boolean deleteData = false;
|
|
|
switch (mMatcher.match(uri)) {
|
|
|
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);
|
|
|
break;
|
|
|
case URI_DATA:
|
|
|
count = db.delete(TABLE.DATA, selection, selectionArgs);
|
|
|
deleteData = true;
|
|
|
break;
|
|
|
case URI_DATA_ITEM:
|
|
|
id = uri.getPathSegments().get(1);
|
|
|
count = db.delete(TABLE.DATA,
|
|
|
DataColumns.ID + "=" + id + parseSelection(selection), selectionArgs);
|
|
|
deleteData = true;
|
|
|
break;
|
|
|
default:
|
|
|
throw new IllegalArgumentException("Unknown URI " + uri);
|
|
|
}
|
|
|
if (count > 0) {
|
|
|
if (deleteData) {
|
|
|
getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null);
|
|
|
}
|
|
|
getContext().getContentResolver().notifyChange(uri, null);
|
|
|
}
|
|
|
return count;
|
|
|
}
|
|
|
|
|
|
@Override
|
|
|
// 更新一个uri
|
|
|
public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
|
|
|
int count = 0; // 记录更新的行数
|
|
|
String id = null; // 用于存储URI中的ID部分
|
|
|
SQLiteDatabase db = mHelper.getWritableDatabase(); // 获取可写的数据库实例
|
|
|
boolean updateData = false; // 标记是否需要更新数据表
|
|
|
|
|
|
// 根据URI匹配不同的操作
|
|
|
switch (mMatcher.match(uri)) {
|
|
|
case URI_NOTE:
|
|
|
// 更新笔记表中的多条记录
|
|
|
increaseNoteVersion(-1, selection, selectionArgs); // 增加笔记版本号
|
|
|
count = db.update(TABLE.NOTE, values, selection, selectionArgs); // 执行更新操作
|
|
|
break;
|
|
|
case URI_NOTE_ITEM:
|
|
|
// 更新笔记表中的单条记录
|
|
|
id = uri.getPathSegments().get(1); // 从URI中获取ID
|
|
|
increaseNoteVersion(Long.valueOf(id), selection, selectionArgs); // 增加指定笔记的版本号
|
|
|
count = db.update(TABLE.NOTE, values, NoteColumns.ID + "=" + id
|
|
|
+ parseSelection(selection), selectionArgs); // 执行更新操作
|
|
|
break;
|
|
|
case URI_DATA:
|
|
|
// 更新数据表中的多条记录
|
|
|
count = db.update(TABLE.DATA, values, selection, selectionArgs); // 执行更新操作
|
|
|
updateData = true; // 设置更新数据表的标记为true
|
|
|
break;
|
|
|
case URI_DATA_ITEM:
|
|
|
// 更新数据表中的单条记录
|
|
|
id = uri.getPathSegments().get(1); // 从URI中获取ID
|
|
|
count = db.update(TABLE.DATA, values, DataColumns.ID + "=" + id
|
|
|
+ parseSelection(selection), selectionArgs); // 执行更新操作
|
|
|
updateData = true; // 设置更新数据表的标记为true
|
|
|
break;
|
|
|
default:
|
|
|
// 如果URI不匹配任何已知类型，则抛出异常
|
|
|
throw new IllegalArgumentException("Unknown URI " + uri);
|
|
|
}
|
|
|
|
|
|
// 如果有行被更新，则通知相关URI的监听器
|
|
|
if (count > 0) {
|
|
|
if (updateData) {
|
|
|
// 如果更新了数据表，则通知笔记表的URI
|
|
|
getContext().getContentResolver().notifyChange(Notes.CONTENT_NOTE_URI, null);
|
|
|
}
|
|
|
// 通知当前URI的监听器
|
|
|
getContext().getContentResolver().notifyChange(uri, null);
|
|
|
}
|
|
|
return count; // 返回更新的行数
|
|
|
}
|
|
|
|
|
|
/// 将字符串解析成规定格式
|
|
|
private String parseSelection(String selection) {
|
|
|
// 如果传入的选择字符串不为空，则在 selection 前后添加 " AND (" 和 ")"，否则返回空字符串
|
|
|
return (!TextUtils.isEmpty(selection) ? " AND (" + selection + ')' : "");
|
|
|
}
|
|
|
|
|
|
// 增加一个noteVersion
|
|
|
private void increaseNoteVersion(long id, String selection, String[] selectionArgs) {
|
|
|
// 创建StringBuilder对象，用于构建SQL语句
|
|
|
StringBuilder sql = new StringBuilder(120);
|
|
|
sql.append("UPDATE "); // 添加UPDATE关键字
|
|
|
sql.append(TABLE.NOTE); // 添加表名NOTE
|
|
|
sql.append(" SET "); // 添加SET关键字
|
|
|
sql.append(NoteColumns.VERSION); // 添加版本号列名
|
|
|
sql.append("=" + NoteColumns.VERSION + "+1 "); // 版本号列值加1
|
|
|
|
|
|
// 如果ID大于0或者选择字符串不为空，则添加WHERE关键字
|
|
|
if (id > 0 || !TextUtils.isEmpty(selection)) {
|
|
|
sql.append(" WHERE ");
|
|
|
}
|
|
|
// 如果ID大于0，则添加ID等于指定值的条件
|
|
|
if (id > 0) {
|
|
|
sql.append(NoteColumns.ID + "=" + String.valueOf(id));
|
|
|
}
|
|
|
// 如果选择字符串不为空，则添加解析后的选择字符串作为条件
|
|
|
if (!TextUtils.isEmpty(selection)) {
|
|
|
String selectString = id > 0 ? parseSelection(selection) : selection;
|
|
|
// 将选择字符串中的占位符替换为实际的参数值
|
|
|
for (String args : selectionArgs) {
|
|
|
selectString = selectString.replaceFirst("\\?", args);
|
|
|
}
|
|
|
sql.append(selectString);
|
|
|
}
|
|
|
|
|
|
// 使用execSQL方法执行构建的SQL语句
|
|
|
mHelper.getWritableDatabase().execSQL(sql.toString());
|
|
|
}
|
|
|
|
|
|
@Override
|
|
|
public String getType(Uri uri) {
|
|
|
// TODO: 需要实现该方法来返回给定URI的MIME类型，暂时返回null
|
|
|
return null;
|
|
|
}
|
