001/*
002 * Copyright 2015-2022 Transmogrify LLC, 2022-2023 Revetware LLC.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package com.pyranid;
018
019import javax.annotation.Nonnull;
020import javax.sql.DataSource;
021import java.sql.Connection;
022import java.sql.DatabaseMetaData;
023import java.sql.SQLException;
024
025import static java.util.Objects.requireNonNull;
026
027/**
028 * Identifies different types of databases, which allows for special platform-specific handling.
029 *
030 * @author <a href="https://www.revetkn.com">Mark Allen</a>
031 * @since 1.0.0
032 */
033public enum DatabaseType {
034        /**
035         * A database which requires no special handling.
036         */
037        GENERIC,
038        /**
039         * An Oracle database.
040         */
041        ORACLE;
042
043        /**
044         * Determines the type of database to which the given {@code dataSource} connects.
045         * <p>
046         * Note: this will establish a {@link Connection} to the database.
047         *
048         * @param dataSource the database connection factory
049         * @return the type of database
050         * @throws DatabaseException if an exception occurs while attempting to read database metadata
051         */
052        @Nonnull
053        public static DatabaseType fromDataSource(@Nonnull DataSource dataSource) {
054                requireNonNull(dataSource);
055
056                DatabaseType databaseType = DatabaseType.GENERIC;
057
058                try {
059                        try (Connection connection = dataSource.getConnection()) {
060                                DatabaseMetaData databaseMetaData = connection.getMetaData();
061                                String databaseProductName = databaseMetaData.getDatabaseProductName();
062                                if (databaseProductName != null && databaseProductName.startsWith("Oracle"))
063                                        databaseType = DatabaseType.ORACLE;
064                        }
065                } catch (SQLException e) {
066                        throw new DatabaseException("Unable to connect to database to determine its type", e);
067                }
068
069                return databaseType;
070        }
071}