org.apache.torque.engine.platform.PlatformFactory Maven / Gradle / Ivy

package org.apache.torque.engine.platform;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */

import java.util.HashMap;
import java.util.Map;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * Factory class responsible for creating Platform objects that define RDBMS platform specific behaviour.
 */
public class PlatformFactory {
	private static Map platforms = new HashMap();
	private static Log log = LogFactory.getLog(PlatformFactory.class);

	/**
	 * Returns the Platform for a platform name.
	 *
	 * @param dbms
	 *            name of the platform
	 */
	public static Platform getPlatformFor(String dbms) {
		Platform result = null;
		String platformName = null;

		result = (Platform) getPlatforms().get(dbms);
		if (result == null) {
			try {
				platformName = getClassnameFor(dbms);
				Class platformClass = Class.forName(platformName);
				result = (Platform) platformClass.newInstance();
			} catch (Exception e) {
				throw new IllegalStateException(e);
			}
			getPlatforms().put(dbms, result); // cache the Platform
		}
		return result;
	}

	/**
	 * compute the name of the concrete Class representing the Platform specified by platform
	 *
	 * @param platform
	 *            the name of the platform as specified in the repository
	 */
	private static String getClassnameFor(String platform) {
		String pf = "Default";
		if (platform != null) {
			pf = platform;
		}
		return "org.apache.torque.engine.platform.Platform" + pf.substring(0, 1).toUpperCase() + pf.substring(1) + "Impl";
	}

	/**
	 * Gets the platforms.
	 *
	 * @return Returns a HashMap
	 */
	private static Map getPlatforms() {
		return platforms;
	}
}