com.liferay.alerts.database.DatabaseHelper.java Source code

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Here is the source code for com.liferay.alerts.database.DatabaseHelper.java

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/**
 * Copyright (c) 2000-present Liferay, Inc. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2.1 of the License, or (at your option)
 * any later version.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
 * details.
 */

package com.liferay.alerts.database;

import android.content.ContentValues;
import android.content.Context;

import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

import android.util.Log;

import com.liferay.alerts.model.Alert;
import com.liferay.alerts.util.CharPool;

import org.json.JSONException;
import org.json.JSONObject;

/**
 * @author Silvio Santos
 * @author Bruno Farache
 */
public class DatabaseHelper extends SQLiteOpenHelper {

    public static DatabaseHelper getInstance(Context context) {
        if (_instance == null) {
            _instance = new DatabaseHelper(context.getApplicationContext());
        }

        return _instance;
    }

    public void deleteDatabase(Context context) {
        AlertDAO.destroy();
        UserDAO.destroy();

        try {
            _instance.close();
        } catch (RuntimeException re) {
        }

        context.deleteDatabase(_DATABASE_NAME);
    }

    public void onCreate(SQLiteDatabase database) {
        UserDAO userDAO = new UserDAO();
        AlertDAO alertDAO = new AlertDAO();

        database.execSQL(userDAO.getCreateTableSQL());
        database.execSQL(alertDAO.getCreateTableSQL());
    }

    public void onOpen(SQLiteDatabase database) {
        super.onOpen(database);

        database.execSQL(_FOREIGN_KEYS_ON);
    }

    @Override
    public void onUpgrade(SQLiteDatabase database, int oldVersion, int newVersion) {

        if (oldVersion < 2) {
            _upgradeToVersion2(database);
        }

        if (oldVersion < 3) {
            _upgradeToVersion3(database);
        }
    }

    private DatabaseHelper(Context context) {
        super(context, _DATABASE_NAME, null, _DATABASE_VERSION);
    }

    private void _convertMessageToJSONObject(SQLiteDatabase database) {
        StringBuilder select = new StringBuilder();

        select.append("SELECT ");
        select.append(Alert.ID);
        select.append(", ");
        select.append(Alert.PAYLOAD);
        select.append(" FROM ");
        select.append(AlertDAO.TABLE_NAME);

        Cursor cursor = database.rawQuery(select.toString(), null);

        while (cursor.moveToNext()) {
            try {
                long id = cursor.getLong(cursor.getColumnIndex(Alert.ID));
                String payload = cursor.getString(cursor.getColumnIndex(Alert.PAYLOAD));

                JSONObject jsonObject = new JSONObject();
                jsonObject.put(Alert.MESSAGE, payload);

                ContentValues values = new ContentValues();
                values.put(Alert.PAYLOAD, jsonObject.toString());

                StringBuilder sb = new StringBuilder();

                sb.append(Alert.ID);
                sb.append(CharPool.SPACE);
                sb.append("= ?");

                String whereClause = sb.toString();

                String[] whereArgs = { String.valueOf(id) };

                database.update(AlertDAO.TABLE_NAME, values, whereClause, whereArgs);
            } catch (JSONException je) {
                Log.e(_TAG, "Couldn't convert message.", je);
            }
        }
    }

    private void _renameColumn(SQLiteDatabase database, String tableName, String createTableSQL) {

        String temp = "TEMP_" + tableName;

        StringBuilder alter = new StringBuilder();

        alter.append("ALTER TABLE ");
        alter.append(tableName);
        alter.append(" RENAME TO ");
        alter.append(temp);

        database.execSQL(alter.toString());
        database.execSQL(createTableSQL);

        StringBuilder copy = new StringBuilder();

        copy.append("INSERT INTO ");
        copy.append(tableName);
        copy.append(" SELECT * FROM ");
        copy.append(temp);

        database.execSQL(copy.toString());

        StringBuilder drop = new StringBuilder();

        drop.append("DROP TABLE ");
        drop.append(temp);

        database.execSQL(drop.toString());
    }

    private void _upgradeToVersion2(SQLiteDatabase database) {
        _renameColumn(database, AlertDAO.TABLE_NAME, new AlertDAO().getCreateTableSQL());

        _convertMessageToJSONObject(database);
    }

    private void _upgradeToVersion3(SQLiteDatabase database) {
        StringBuilder alter = new StringBuilder();

        alter.append("ALTER TABLE ");
        alter.append(AlertDAO.TABLE_NAME);
        alter.append(" ADD COLUMN ");
        alter.append(Alert.READ);
        alter.append(CharPool.SPACE);
        alter.append(TableColumn.INTEGER);
        alter.append(" DEFAULT 0");

        database.execSQL(alter.toString());
    }

    private static final String _DATABASE_NAME = "liferay-alerts.db";

    private static final int _DATABASE_VERSION = 3;

    private static final String _FOREIGN_KEYS_ON = "PRAGMA foreign_keys = ON;";

    private static final String _TAG = DatabaseHelper.class.getSimpleName();

    private static DatabaseHelper _instance;

}