package org.apache.ojb.otm.transaction;

 /* Copyright 2003-2005 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 java.util.HashMap;

 import javax.transaction.SystemException;

 import javax.transaction.TransactionManager;

 import org.apache.ojb.broker.PBKey;

 import org.apache.ojb.broker.transaction.tm.TransactionManagerFactoryFactory;

 import org.apache.ojb.broker.transaction.tm.TransactionManagerFactoryException;

 import org.apache.ojb.otm.OTMConnection;

 import org.apache.ojb.otm.core.BaseConnection;

 import org.apache.ojb.otm.core.Transaction;

 import org.apache.ojb.otm.core.TransactionException;

 /**

  * Factory for OTM Transactions within a managed environment (JTA).

  *

  * @author <a href="mailto:rraghuram@hotmail.com">Raghu Rajah</a>

  *

  */

 public abstract class ManagedTransactionFactory implements TransactionFactory

 {

     private HashMap _transactionMap;

     private TransactionManager tm;

         /**

          * Constructor for ManagedTransactionFactory.

          */

         public ManagedTransactionFactory()

         {

                 _transactionMap = new HashMap();

         }

     //////////////////////////////////////////////////////

     // TransactionFactory protocol

     //////////////////////////////////////////////////////

         /**

          * @see org.apache.ojb.otm.transaction.TransactionFactory#getTransactionForConnection(OTMConnection)

          */

         public Transaction getTransactionForConnection(OTMConnection connection)

         {

         if (!(connection instanceof BaseConnection))

         {

             throw new TransactionFactoryException("Unknown connection type");

         }

         BaseConnection baseConnection = (BaseConnection) connection;

                 javax.transaction.Transaction jtaTx = getJTATransaction();

         if (jtaTx == null)

         {

             throw new TransactionFactoryException("Unable to get the JTA Transaction");

         }

         Transaction tx = (Transaction) _transactionMap.get(jtaTx);

         if (tx == null)

         {

             tx = new Transaction();

             _transactionMap.put(jtaTx, tx);

         }

         // ensure that this connection is registered into this transaction

         tx.registerConnection(baseConnection);

         return tx;

         }

     /**

      * @see org.apache.ojb.otm.transaction.TransactionFactory#acquireConnection

      */

     public OTMConnection acquireConnection(PBKey pbKey)

     {

         return new ManagedConnection(pbKey);

     }

     //////////////////////////////////////////

     // Other operations

     //////////////////////////////////////////

     public javax.transaction.Transaction getJTATransaction()

     {

         if(tm == null)

         {

             try

             {

                 tm = TransactionManagerFactoryFactory.instance().getTransactionManager();

             }

             catch (TransactionManagerFactoryException e)

             {

                 throw new TransactionFactoryException("Can't instantiate TransactionManagerFactory", e);

             }

         }

         try

         {

             return tm.getTransaction();

         }

         catch(SystemException e)

         {

             throw new TransactionFactoryException("Error acquiring JTA Transaction", e);

         }

     }

     private static class ManagedConnection extends BaseConnection

     {

         public ManagedConnection (PBKey pbKey)

         {

             super(pbKey);

         }

         /**

          * @see org.apache.ojb.otm.core.BaseConnection#transactionBegin()

          */

         public void transactionBegin() throws TransactionException

         {

             // Nothing to do!

         }

         /**

          * @see org.apache.ojb.otm.core.BaseConnection#transactionPrepare()

          */

         public void transactionPrepare() throws TransactionException

         {

             // Nothing to do, since all resources are managed by JTS and will be committed

             // directly.

         }

         /**

          * @see org.apache.ojb.otm.core.BaseConnection#transactionCommit()

          */

         public void transactionCommit() throws TransactionException

         {

             // Nothing to do, since all resources are managed by JTS and will be committed

             // directly.

         }

         /**

          * @see org.apache.ojb.otm.core.BaseConnection#transactionRollback()

          */

         public void transactionRollback() throws TransactionException

         {

             // Nothing to do, since all resources are managed by JTS and will be rolled back

             // directly.

         }

     }

 }