Mercurial > 510Connectbot
view src/com/five_ten_sg/connectbot/util/RobustSQLiteOpenHelper.java @ 385:b12705abba3e
wizard and help present help pages in the same order
author | Carl Byington <carl@five-ten-sg.com> |
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date | Wed, 06 Aug 2014 11:49:01 -0700 |
parents | 0ce5cc452d02 |
children |
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/* * ConnectBot: simple, powerful, open-source SSH client for Android * Copyright 2007 Kenny Root, Jeffrey Sharkey * * 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 com.five_ten_sg.connectbot.util; import java.util.LinkedList; import java.util.List; import android.content.Context; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteDatabase.CursorFactory; import android.database.sqlite.SQLiteException; import android.database.sqlite.SQLiteOpenHelper; /** * @author Kenny Root * */ public abstract class RobustSQLiteOpenHelper extends SQLiteOpenHelper { private static List<String> mTableNames = new LinkedList<String>(); private static List<String> mIndexNames = new LinkedList<String>(); public RobustSQLiteOpenHelper(Context context, String name, CursorFactory factory, int version) { super(context, name, factory, version); } protected static void addTableName(String tableName) { mTableNames.add(tableName); } protected static void addIndexName(String indexName) { mIndexNames.add(indexName); } @Override public void onCreate(SQLiteDatabase db) { dropAllTables(db); } @Override public final void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { try { onRobustUpgrade(db, oldVersion, newVersion); } catch (SQLiteException e) { // The database has entered an unknown state. Try to recover. try { regenerateTables(db); } catch (SQLiteException e2) { dropAndCreateTables(db); } } } public abstract void onRobustUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) throws SQLiteException; private void regenerateTables(SQLiteDatabase db) { dropAllTablesWithPrefix(db, "OLD_"); for (String tableName : mTableNames) db.execSQL("ALTER TABLE " + tableName + " RENAME TO OLD_" + tableName); onCreate(db); for (String tableName : mTableNames) repopulateTable(db, tableName); dropAllTablesWithPrefix(db, "OLD_"); } private void repopulateTable(SQLiteDatabase db, String tableName) { String columns = getTableColumnNames(db, tableName); StringBuilder sb = new StringBuilder(); sb.append("INSERT INTO ") .append(tableName) .append(" (") .append(columns) .append(") SELECT ") .append(columns) .append(" FROM OLD_") .append(tableName); String sql = sb.toString(); db.execSQL(sql); } private String getTableColumnNames(SQLiteDatabase db, String tableName) { StringBuilder sb = new StringBuilder(); Cursor fields = db.rawQuery("PRAGMA table_info(" + tableName + ")", null); while (fields.moveToNext()) { if (!fields.isFirst()) sb.append(", "); sb.append(fields.getString(1)); } fields.close(); return sb.toString(); } private void dropAndCreateTables(SQLiteDatabase db) { dropAllTables(db); onCreate(db); } private void dropAllTablesWithPrefix(SQLiteDatabase db, String prefix) { for (String indexName : mIndexNames) db.execSQL("DROP INDEX IF EXISTS " + prefix + indexName); for (String tableName : mTableNames) db.execSQL("DROP TABLE IF EXISTS " + prefix + tableName); } private void dropAllTables(SQLiteDatabase db) { dropAllTablesWithPrefix(db, ""); } }