package org.apache.ojb.broker.platforms;

 /* Copyright 2002-2005 The Apache Software Foundation

  *

  * 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.

  */

 import org.apache.ojb.broker.metadata.JdbcConnectionDescriptor;

 import org.apache.ojb.broker.util.logging.LoggerFactory;

 import org.apache.ojb.broker.util.ClassHelper;

 import java.util.HashMap;

 /**

  * this factory class is responsible to create Platform objects that

  * define RDBMS platform specific behaviour.

  * @version         1.0

  * @author                Thomas Mahler

  */

 public class PlatformFactory

 {

     private static HashMap platforms = new HashMap();

     /**

      * returns the Platform matching to the JdbcConnectionDescriptor jcd.

      * The method jcd.getDbms(...) is used to determine the Name of the

      * platform.

      * BRJ : cache platforms

      * @param jcd the JdbcConnectionDescriptor defining the platform

      */

     public static Platform getPlatformFor(JdbcConnectionDescriptor jcd)

     {

         String dbms = jcd.getDbms();

         Platform result = null;

         String platformName = null;

         result = (Platform) getPlatforms().get(dbms);

         if (result == null)

         {

             try

             {

                 platformName = getClassnameFor(dbms);

                 Class platformClass = ClassHelper.getClass(platformName);

                 result = (Platform) platformClass.newInstance();

             }

             catch (Throwable t)

             {

                 LoggerFactory.getDefaultLogger().warn(

                         "[PlatformFactory] problems with platform " + platformName, t);

                 LoggerFactory.getDefaultLogger().warn(

                         "[PlatformFactory] OJB will use PlatformDefaultImpl instead");

                 result = new PlatformDefaultImpl();

             }

             getPlatforms().put(dbms, result); // cache the Platform

         }

         return result;

     }

     /**

      * compute the name of the concrete Class representing the Platform

      * specified by <code>platform</code>

      * @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.ojb.broker.platforms.Platform" + pf.substring(0, 1).toUpperCase() + pf.substring(1) + "Impl";

     }

     /**

      * Gets the platforms.

      * @return Returns a HashMap

      */

     private static HashMap getPlatforms()

     {

         return platforms;

     }

 }