Java tutorial
/* Copyright 2004 Tacit Knowledge * * 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.tacitknowledge.util.migration; import org.apache.commons.lang.StringUtils; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; /** * Returns the strategy we should we apply to decide if a patch needs to be applied * or we should rollback * * @author Oscar Gonzalez (oscar@tacitknowledge.com) */ public class MigrationRunnerFactory { private static Log log = LogFactory.getLog(MigrationRunnerFactory.class); public static final String DEFAULT_MIGRATION_STRATEGY = "com.tacitknowledge.util.migration.OrderedMigrationRunnerStrategy"; public static MigrationRunnerStrategy getMigrationRunnerStrategy(String strategy) { log.info("Strategy received '" + strategy + "'"); if (StringUtils.isBlank(strategy)) { return new OrderedMigrationRunnerStrategy(); } try { Class c = Class.forName(strategy.trim()); MigrationRunnerStrategy runnerStrategy = (MigrationRunnerStrategy) c.newInstance(); return runnerStrategy; } catch (Exception e) { throw new IllegalArgumentException("Strategy selected " + strategy + " cannot be instantiated ", e); } } }