package org.apache.ojb.odmg.locking;

 /* 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.commons.lang.SystemUtils;

 import org.apache.ojb.broker.OJBRuntimeException;

 import org.apache.ojb.broker.locking.LockManager;

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

 import org.apache.ojb.broker.util.configuration.Configuration;

 import org.apache.ojb.broker.util.configuration.impl.OjbConfigurator;

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

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

 /**

  * This factory class creates LockManager instances according

  * to the setting in the OJB properties file.

  */

 public class LockManagerFactory

 {

     private static LockManagerFactory lockManagerFactory = null;

     private Logger log = LoggerFactory.getLogger(LockManagerFactory.class);

     private org.apache.ojb.odmg.locking.LockManager lockManager;

     private LockManagerFactory()

     {

         init();

     }

     private void init()

     {

         Configuration conf = OjbConfigurator.getInstance().getConfigurationFor(null);

         Class lockMapClass = conf.getClass("LockMapClass", Object.class);

         Class lockManagerClass = conf.getClass("LockManagerClass", null);

         if(lockManagerClass == null)

         {

             throw new OJBRuntimeException(buildErrorMsg(lockMapClass, lockManagerClass));

         }

         if(!lockMapClass.equals(Object.class))

         {

             // use the deprecated old odmg locking stuff

             log.info("Setup *deprecated* odmg-locking api.");

             log.info("Used LockManagerClass=" + lockManagerClass);

             log.info("Used LockMapClass=" + lockMapClass);

             if(!org.apache.ojb.odmg.locking.LockManager.class.isAssignableFrom(lockManagerClass))

             {

                 throw new OJBRuntimeException(buildErrorMsg(lockMapClass, lockManagerClass));

             }

             setupLockManager(lockManagerClass);

         }

         else

         {

             // use the kernel locking api

             log.info("Setup odmg-locking api.");

             log.info("Used LockManagerClass=" + lockManagerClass);

             if(org.apache.ojb.odmg.locking.LockManager.class.isAssignableFrom(lockManagerClass))

             {

                 throw new OJBRuntimeException(buildErrorMsg(lockMapClass, lockManagerClass));

             }

             setupLockManager(conf, lockManagerClass);

         }

     }

     private void setupLockManager(Configuration conf, Class lockManagerClass)

     {

         long timeout = conf.getInteger("LockTimeout", 60000);

         log.info("LockTimeout=" + timeout);

         try

         {

             LockManager lm = (LockManager) ClassHelper.newInstance(lockManagerClass);

             lm.setLockTimeout(timeout);

             lockManager = new LockManagerOdmgImpl(lm);

         }

         catch(Exception e)

         {

             throw new OJBRuntimeException("Can't setup odmg lock manager instance", e);

         }

     }

     private void setupLockManager(Class lockManagerClass)

     {

         try

         {

             lockManager = (org.apache.ojb.odmg.locking.LockManager) ClassHelper.newInstance(lockManagerClass);

         }

         catch(Exception e)

         {

             throw new OJBRuntimeException("Can't setup odmg lock manager instance", e);

         }

     }

     private String buildErrorMsg(Class lockMap, Class lockManager)

     {

         String eol = SystemUtils.LINE_SEPARATOR;

         StringBuffer msg = new StringBuffer("Can't setup LockManager. Current used properties are:" + eol);

         msg.append("LockMapClass=").append(lockMap != null ? lockMap.getName() : null)

                 .append(eol)

                 .append("LockManagerClass=").append(lockManager != null ? lockManager.getName() : null).append(eol)

                 .append("For correct setup of the lock manager, please enable the 'LockManagerClass' property")

                 .append(" in OJB configuration, OJB expects an 'org.apache.ojb.broker.locking.LockManager' implementation class.")

                 .append(eol)

                 .append("Or to enable the *deprecated* odmg-locking api enable the 'LockMapClass' AND the 'LockManager' properties")

                 .append(", in this case OJB expects an 'org.apache.ojb.odmg.locking.LockManager' implementation class.");

         return msg.toString();

     }

     private org.apache.ojb.odmg.locking.LockManager getManager()

     {

         return lockManager;

     }

     /**

      * Get a {@link org.apache.ojb.odmg.locking.LockManager} instance. The implementation class is

      * configured in the OJB properties file.

      */

     public static synchronized org.apache.ojb.odmg.locking.LockManager getLockManager()

     {

         if(lockManagerFactory == null)

         {

             lockManagerFactory = new LockManagerFactory();

         }

         return lockManagerFactory.getManager();

     }

 }