spring-jdo2/src/main/java/org/apache/archiva/redback/components/jdo/RedbackJdoUtils.java - archiva-redback-components - Git at Google

 package org.apache.archiva.redback.components.jdo;

 /*
  * 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 org.apache.commons.lang.StringUtils;
 import org.slf4j.LoggerFactory;

 import javax.jdo.Extent;
 import javax.jdo.JDOException;
 import javax.jdo.JDOHelper;
 import javax.jdo.JDOObjectNotFoundException;
 import javax.jdo.JDOUserException;
 import javax.jdo.PersistenceManager;
 import javax.jdo.Query;
 import javax.jdo.Transaction;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;

 /**
  * @author <a href="mailto:trygvis@inamo.no">Trygve Laugst&oslash;l</a>
  */
 public class RedbackJdoUtils
 {
     /**
      * This operation as opposed to
      * {@link #updateObject(PersistenceManager, Object)} is an
      * <em>new school</em> technique, which <em><b>does not</b></em>
      * requires that the object be previously added using
      * {@link #addObject(PersistenceManager, Object)} or
      * {@link #addObject(PersistenceManager, Object, String[])}.
      *
      * @param pm
      * @param object
      * @param fetchGroups
      * @return
      * @throws RedbackStoreException
      * @see {@link #updateObject(PersistenceManager, Object)} for old technique.
      */
     public static Object saveObject( PersistenceManager pm, Object object, String fetchGroups[] )
         throws RedbackStoreException
     {
         Transaction tx = pm.currentTransaction();

         try
         {
             tx.begin();

             if ( ( JDOHelper.getObjectId( object ) != null ) && !JDOHelper.isDetached( object ) )
             {
                 throw new RedbackStoreException( "Existing object is not detached: " + object );
             }

             if ( fetchGroups != null )
             {
                 for ( int i = 0; i >= fetchGroups.length; i++ )
                 {
                     pm.getFetchPlan().addGroup( fetchGroups[i] );
                 }
             }

             pm.makePersistent( object );

             object = pm.detachCopy( object );

             tx.commit();

             return object;
         }
         finally
         {
             rollbackIfActive( tx );
         }
     }

     public static Object addObject( PersistenceManager pm, Object object )
     {
         return addObject( pm, object, null );
     }

     public static Object addObject( PersistenceManager pm, Object object, String fetchGroups[] )
     {
         Transaction tx = pm.currentTransaction();

         try
         {
             tx.begin();

             if ( fetchGroups != null )
             {
                 for ( int i = 0; i >= fetchGroups.length; i++ )
                 {
                     pm.getFetchPlan().addGroup( fetchGroups[i] );
                 }
             }

             pm.makePersistent( object );

             object = pm.detachCopy( object );

             tx.commit();

             return object;
         }
         finally
         {
             rollbackIfActive( tx );
         }
     }

     public static void removeObject( PersistenceManager pm, Object o )
     {
         Transaction tx = pm.currentTransaction();

         try
         {
             tx.begin();

             o = pm.getObjectById( pm.getObjectId( o ) );

             pm.deletePersistent( o );

             tx.commit();
         }
         finally
         {
             rollbackIfActive( tx );
         }
     }

     /**
      * This operation is an <em>old school</em> technique, which required that
      * the object be previously added using
      * {@link #addObject(PersistenceManager, Object)} or
      * {@link #addObject(PersistenceManager, Object, String[])}.
      *
      * @param pm
      * @param object
      * @return
      * @throws RedbackStoreException
      * @see {@link #saveObject(PersistenceManager, Object, String[])}
      */
     public static Object updateObject( PersistenceManager pm, Object object )
         throws RedbackStoreException
     {
         Object ret = object;
         Transaction tx = pm.currentTransaction();

         try
         {
             tx.begin();

             if ( !JDOHelper.isDetached( object ) )
             {
                 throw new RedbackStoreException( "Not detached: " + object );
             }

             try
             {
                 ret = pm.makePersistent( object );
             }
             catch ( NullPointerException npe )
             {
                 // Do not hide useful error messages.
                 // This exception can occur if you have an object with a List
                 // that isn't initialized yet.
                 throw new RedbackStoreException( "Unable to update object due to unexpected null value.", npe );
             }
             catch ( Exception e )
             {
                 // TODO: Refactor to avoid using Exception catch-all.
                 // We retry if we obtain an exception like a dead lock
                 ret = pm.makePersistent( object );
             }

             tx.commit();
         }
         finally
         {
             rollbackIfActive( tx );
         }

         return ret;
     }

     public static Object makePersistent( PersistenceManager pm, Object object, boolean detach )
     {
         pm.makePersistent( object );

         Object id = pm.getObjectId( object );

         Object persistentObject = pm.getObjectById( id );

         if ( detach )
         {
             persistentObject = pm.detachCopy( persistentObject );
         }

         return persistentObject;
     }

     public static Object getObjectById( PersistenceManager pm, Class clazz, String id )
         throws RedbackObjectNotFoundException, RedbackStoreException
     {
         return getObjectById( pm, clazz, id, null );
     }

     public static Object getObjectById( PersistenceManager pm, Class clazz, String id, String fetchGroup )
         throws RedbackStoreException, RedbackObjectNotFoundException
     {
         if ( StringUtils.isBlank( id ) )
         {
             throw new RedbackStoreException( "Unable to get object '" + clazz.getName() + "' from jdo using null id." );
         }

         Transaction tx = pm.currentTransaction();

         try
         {
             tx.begin();

             if ( fetchGroup != null )
             {
                 pm.getFetchPlan().addGroup( fetchGroup );
             }

             Object objectId = pm.newObjectIdInstance( clazz, id );

             Object object = pm.getObjectById( objectId );

             object = pm.detachCopy( object );

             tx.commit();

             return object;
         }
         catch ( JDOObjectNotFoundException e )
         {
             throw new RedbackObjectNotFoundException( clazz.getName(), id );
         }
         catch ( JDOException e )
         {
             throw new RedbackStoreException( "Error handling JDO", e );
         }
         finally
         {
             rollbackIfActive( tx );
         }
     }

     /**
      * @deprecated Use {@link #getObjectById(PersistenceManager, Class, long)}
      *             instead
      */
     public static Object getObjectById( PersistenceManager pm, Class clazz, int id )
         throws RedbackStoreException, RedbackObjectNotFoundException
     {
         return getObjectById( pm, clazz, (long) id );
     }

     /**
      * Obtain and return an {@link Object} instance from the underlying data
      * store based on the passed in identifier.
      *
      * @param pm    {@link PersistenceManager} manager to use to query database.
      * @param clazz Expected {@link Class} of the Object instance to be
      *              returned.
      * @param id    Object identifier to match in the database.
      * @return Object instance that matches the passed in identifier.
      * @throws RedbackStoreException          if there was an error querying the database
      *                                       for the object.
      * @throws RedbackObjectNotFoundException if a matching object could not be
      *                                       found.
      */
     public static Object getObjectById( PersistenceManager pm, Class clazz, long id )
         throws RedbackStoreException, RedbackObjectNotFoundException
     {
         return getObjectById( pm, clazz, id, null );
     }

     /**
      * @deprecated Use
      *             {@link #getObjectById(PersistenceManager, Class, long, String)}
      *             instead
      */
     public static Object getObjectById( PersistenceManager pm, Class clazz, int id, String fetchGroup )
         throws RedbackStoreException, RedbackObjectNotFoundException
     {
         return getObjectById( pm, clazz, (long) id, fetchGroup );
     }

     /**
      * Obtain and return an {@link Object} instance from the underlying data
      * store based on the passed in identifier.
      *
      * @param pm         {@link PersistenceManager} manager to use to query database.
      * @param clazz      Expected {@link Class} of the Object instance to be
      *                   returned.
      * @param id         Object identifier to match in the database.
      * @param fetchGroup TODO: Document!
      * @return Object instance that matches the passed in identifier.
      * @throws RedbackStoreException          if there was an error querying the database
      *                                       for the object.
      * @throws RedbackObjectNotFoundException if a matching object could not be
      *                                       found.
      */
     public static Object getObjectById( PersistenceManager pm, Class clazz, long id, String fetchGroup )
         throws RedbackStoreException, RedbackObjectNotFoundException
     {
         Transaction tx = pm.currentTransaction();

         try
         {
             tx.begin();

             if ( fetchGroup != null )
             {
                 pm.getFetchPlan().addGroup( fetchGroup );
             }

             Object objectId = pm.newObjectIdInstance( clazz, Long.valueOf( id ) );

             Object object = pm.getObjectById( objectId );

             object = pm.detachCopy( object );

             tx.commit();

             return object;
         }
         catch ( JDOObjectNotFoundException e )
         {
             throw new RedbackObjectNotFoundException( clazz.getName(), Long.toString( id ) );
         }
         catch ( JDOException e )
         {
             LoggerFactory.getLogger( RedbackJdoUtils.class ).error( e.getMessage(), e );
             throw new RedbackStoreException( "Error handling JDO", e );
         }
         finally
         {
             rollbackIfActive( tx );
         }
     }

     public static Object getObjectFromQuery( PersistenceManager pm, Class clazz, String idField, String id,
                                              String fetchGroup )
         throws RedbackStoreException, RedbackObjectNotFoundException
     {
         Transaction tx = pm.currentTransaction();

         try
         {
             tx.begin();

             Extent extent = pm.getExtent( clazz, true );

             Query query = pm.newQuery( extent );

             query.declareImports( "import java.lang.String" );

             query.declareParameters( "String " + idField );

             query.setFilter( "this." + idField + " == " + idField );

             Collection result = (Collection) query.execute( id );

             if ( result.size() == 0 )
             {
                 throw new RedbackObjectNotFoundException( clazz.getName(), id );
             }

             if ( result.size() > 1 )
             {
                 throw new RedbackStoreException(
                     "A query for object of " + "type " + clazz.getName() + " on the " + "field '" + idField
                         + "' returned more than one object." );
             }

             pm.getFetchPlan().addGroup( fetchGroup );

             Object object = pm.detachCopy( result.iterator().next() );

             tx.commit();

             return object;
         }
         finally
         {
             rollbackIfActive( tx );
         }
     }

     public static List getAllObjectsDetached( PersistenceManager pm, Class clazz )
     {
         return getAllObjectsDetached( pm, clazz, null );
     }

     public static List getAllObjectsDetached( PersistenceManager pm, Class clazz, String fetchGroup )
     {
         return getAllObjectsDetached( pm, clazz, null, fetchGroup );
     }

     public static List getAllObjectsDetached( PersistenceManager pm, Class clazz, String ordering, String fetchGroup )
     {
         if ( fetchGroup != null )
         {
             return getAllObjectsDetached( pm, clazz, ordering, Collections.singletonList( fetchGroup ) );
         }
         else
         {
             return getAllObjectsDetached( pm, clazz, ordering, Collections.EMPTY_LIST );
         }
     }

     public static List getAllObjectsDetached( PersistenceManager pm, Class clazz, String ordering,
                                               List/* <String> */fetchGroups )
     {
         Transaction tx = pm.currentTransaction();

         try
         {
             tx.begin();

             Extent extent = pm.getExtent( clazz, true );

             Query query = pm.newQuery( extent );

             if ( ordering != null )
             {
                 query.setOrdering( ordering );
             }

             for ( Iterator i = fetchGroups.iterator(); i.hasNext(); )
             {
                 pm.getFetchPlan().addGroup( (String) i.next() );
             }

             List result = (List) query.execute();

             result = (List) pm.detachCopyAll( result );

             tx.commit();

             return result;
         }
         finally
         {
             rollbackIfActive( tx );
         }
     }

     public static void attachAndDelete( PersistenceManager pm, Object object )
     {
         Transaction tx = pm.currentTransaction();

         try
         {
             tx.begin();

             pm.makePersistent( object );

             pm.deletePersistent( object );

             tx.commit();
         }
         finally
         {
             rollbackIfActive( tx );
         }
     }

     public static void rollbackIfActive( Transaction tx )
     {
         PersistenceManager pm = tx.getPersistenceManager();

         try
         {
             if ( tx.isActive() )
             {
                 tx.rollback();
             }
         }
         finally
         {
             closePersistenceManager( pm );
         }
     }

     public static void closePersistenceManager( PersistenceManager pm )
     {
         try
         {
             pm.close();
         }
         catch ( JDOUserException e )
         {
             // ignore
         }
     }

     public static void removeAll( PersistenceManager pm, Class aClass )
     {
         Transaction tx = pm.currentTransaction();

         try
         {
             tx.begin();

             Query query = pm.newQuery( aClass );
             query.deletePersistentAll();

             tx.commit();
         }
         finally
         {
             rollbackIfActive( tx );
         }
     }
 }
	package org.apache.archiva.redback.components.jdo;

	/*
	* 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 org.apache.commons.lang.StringUtils;
	import org.slf4j.LoggerFactory;

	import javax.jdo.Extent;
	import javax.jdo.JDOException;
	import javax.jdo.JDOHelper;
	import javax.jdo.JDOObjectNotFoundException;
	import javax.jdo.JDOUserException;
	import javax.jdo.PersistenceManager;
	import javax.jdo.Query;
	import javax.jdo.Transaction;
	import java.util.Collection;
	import java.util.Collections;
	import java.util.Iterator;
	import java.util.List;

	/**
	* @author <a href="mailto:trygvis@inamo.no">Trygve Laugstøl</a>
	*/
	public class RedbackJdoUtils
	{
	/**
	* This operation as opposed to
	* {@link #updateObject(PersistenceManager, Object)} is an
	* <em>new school</em> technique, which <em><b>does not</b></em>
	* requires that the object be previously added using
	* {@link #addObject(PersistenceManager, Object)} or
	* {@link #addObject(PersistenceManager, Object, String[])}.
	*
	* @param pm
	* @param object
	* @param fetchGroups
	* @return
	* @throws RedbackStoreException
	* @see {@link #updateObject(PersistenceManager, Object)} for old technique.
	*/
	public static Object saveObject( PersistenceManager pm, Object object, String fetchGroups[] )
	throws RedbackStoreException
	{
	Transaction tx = pm.currentTransaction();

	try
	{
	tx.begin();

	if ( ( JDOHelper.getObjectId( object ) != null ) && !JDOHelper.isDetached( object ) )
	{
	throw new RedbackStoreException( "Existing object is not detached: " + object );
	}

	if ( fetchGroups != null )
	{
	for ( int i = 0; i >= fetchGroups.length; i++ )
	{
	pm.getFetchPlan().addGroup( fetchGroups[i] );
	}
	}

	pm.makePersistent( object );

	object = pm.detachCopy( object );

	tx.commit();

	return object;
	}
	finally
	{
	rollbackIfActive( tx );
	}
	}

	public static Object addObject( PersistenceManager pm, Object object )
	{
	return addObject( pm, object, null );
	}

	public static Object addObject( PersistenceManager pm, Object object, String fetchGroups[] )
	{
	Transaction tx = pm.currentTransaction();

	try
	{
	tx.begin();

	if ( fetchGroups != null )
	{
	for ( int i = 0; i >= fetchGroups.length; i++ )
	{
	pm.getFetchPlan().addGroup( fetchGroups[i] );
	}
	}

	pm.makePersistent( object );

	object = pm.detachCopy( object );

	tx.commit();

	return object;
	}
	finally
	{
	rollbackIfActive( tx );
	}
	}

	public static void removeObject( PersistenceManager pm, Object o )
	{
	Transaction tx = pm.currentTransaction();

	try
	{
	tx.begin();

	o = pm.getObjectById( pm.getObjectId( o ) );

	pm.deletePersistent( o );

	tx.commit();
	}
	finally
	{
	rollbackIfActive( tx );
	}
	}

	/**
	* This operation is an <em>old school</em> technique, which required that
	* the object be previously added using
	* {@link #addObject(PersistenceManager, Object)} or
	* {@link #addObject(PersistenceManager, Object, String[])}.
	*
	* @param pm
	* @param object
	* @return
	* @throws RedbackStoreException
	* @see {@link #saveObject(PersistenceManager, Object, String[])}
	*/
	public static Object updateObject( PersistenceManager pm, Object object )
	throws RedbackStoreException
	{
	Object ret = object;
	Transaction tx = pm.currentTransaction();

	try
	{
	tx.begin();

	if ( !JDOHelper.isDetached( object ) )
	{
	throw new RedbackStoreException( "Not detached: " + object );
	}

	try
	{
	ret = pm.makePersistent( object );
	}
	catch ( NullPointerException npe )
	{
	// Do not hide useful error messages.
	// This exception can occur if you have an object with a List
	// that isn't initialized yet.
	throw new RedbackStoreException( "Unable to update object due to unexpected null value.", npe );
	}
	catch ( Exception e )
	{
	// TODO: Refactor to avoid using Exception catch-all.
	// We retry if we obtain an exception like a dead lock
	ret = pm.makePersistent( object );
	}

	tx.commit();
	}
	finally
	{
	rollbackIfActive( tx );
	}

	return ret;
	}

	public static Object makePersistent( PersistenceManager pm, Object object, boolean detach )
	{
	pm.makePersistent( object );

	Object id = pm.getObjectId( object );

	Object persistentObject = pm.getObjectById( id );

	if ( detach )
	{
	persistentObject = pm.detachCopy( persistentObject );
	}

	return persistentObject;
	}

	public static Object getObjectById( PersistenceManager pm, Class clazz, String id )
	throws RedbackObjectNotFoundException, RedbackStoreException
	{
	return getObjectById( pm, clazz, id, null );
	}

	public static Object getObjectById( PersistenceManager pm, Class clazz, String id, String fetchGroup )
	throws RedbackStoreException, RedbackObjectNotFoundException
	{
	if ( StringUtils.isBlank( id ) )
	{
	throw new RedbackStoreException( "Unable to get object '" + clazz.getName() + "' from jdo using null id." );
	}

	Transaction tx = pm.currentTransaction();

	try
	{
	tx.begin();

	if ( fetchGroup != null )
	{
	pm.getFetchPlan().addGroup( fetchGroup );
	}

	Object objectId = pm.newObjectIdInstance( clazz, id );

	Object object = pm.getObjectById( objectId );

	object = pm.detachCopy( object );

	tx.commit();

	return object;
	}
	catch ( JDOObjectNotFoundException e )
	{
	throw new RedbackObjectNotFoundException( clazz.getName(), id );
	}
	catch ( JDOException e )
	{
	throw new RedbackStoreException( "Error handling JDO", e );
	}
	finally
	{
	rollbackIfActive( tx );
	}
	}

	/**
	* @deprecated Use {@link #getObjectById(PersistenceManager, Class, long)}
	* instead
	*/
	public static Object getObjectById( PersistenceManager pm, Class clazz, int id )
	throws RedbackStoreException, RedbackObjectNotFoundException
	{
	return getObjectById( pm, clazz, (long) id );
	}

	/**
	* Obtain and return an {@link Object} instance from the underlying data
	* store based on the passed in identifier.
	*
	* @param pm {@link PersistenceManager} manager to use to query database.
	* @param clazz Expected {@link Class} of the Object instance to be
	* returned.
	* @param id Object identifier to match in the database.
	* @return Object instance that matches the passed in identifier.
	* @throws RedbackStoreException if there was an error querying the database
	* for the object.
	* @throws RedbackObjectNotFoundException if a matching object could not be
	* found.
	*/
	public static Object getObjectById( PersistenceManager pm, Class clazz, long id )
	throws RedbackStoreException, RedbackObjectNotFoundException
	{
	return getObjectById( pm, clazz, id, null );
	}

	/**
	* @deprecated Use
	* {@link #getObjectById(PersistenceManager, Class, long, String)}
	* instead
	*/
	public static Object getObjectById( PersistenceManager pm, Class clazz, int id, String fetchGroup )
	throws RedbackStoreException, RedbackObjectNotFoundException
	{
	return getObjectById( pm, clazz, (long) id, fetchGroup );
	}

	/**
	* Obtain and return an {@link Object} instance from the underlying data
	* store based on the passed in identifier.
	*
	* @param pm {@link PersistenceManager} manager to use to query database.
	* @param clazz Expected {@link Class} of the Object instance to be
	* returned.
	* @param id Object identifier to match in the database.
	* @param fetchGroup TODO: Document!
	* @return Object instance that matches the passed in identifier.
	* @throws RedbackStoreException if there was an error querying the database
	* for the object.
	* @throws RedbackObjectNotFoundException if a matching object could not be
	* found.
	*/
	public static Object getObjectById( PersistenceManager pm, Class clazz, long id, String fetchGroup )
	throws RedbackStoreException, RedbackObjectNotFoundException
	{
	Transaction tx = pm.currentTransaction();

	try
	{
	tx.begin();

	if ( fetchGroup != null )
	{
	pm.getFetchPlan().addGroup( fetchGroup );
	}

	Object objectId = pm.newObjectIdInstance( clazz, Long.valueOf( id ) );

	Object object = pm.getObjectById( objectId );

	object = pm.detachCopy( object );

	tx.commit();

	return object;
	}
	catch ( JDOObjectNotFoundException e )
	{
	throw new RedbackObjectNotFoundException( clazz.getName(), Long.toString( id ) );
	}
	catch ( JDOException e )
	{
	LoggerFactory.getLogger( RedbackJdoUtils.class ).error( e.getMessage(), e );
	throw new RedbackStoreException( "Error handling JDO", e );
	}
	finally
	{
	rollbackIfActive( tx );
	}
	}

	public static Object getObjectFromQuery( PersistenceManager pm, Class clazz, String idField, String id,
	String fetchGroup )
	throws RedbackStoreException, RedbackObjectNotFoundException
	{
	Transaction tx = pm.currentTransaction();

	try
	{
	tx.begin();

	Extent extent = pm.getExtent( clazz, true );

	Query query = pm.newQuery( extent );

	query.declareImports( "import java.lang.String" );

	query.declareParameters( "String " + idField );

	query.setFilter( "this." + idField + " == " + idField );

	Collection result = (Collection) query.execute( id );

	if ( result.size() == 0 )
	{
	throw new RedbackObjectNotFoundException( clazz.getName(), id );
	}

	if ( result.size() > 1 )
	{
	throw new RedbackStoreException(
	"A query for object of " + "type " + clazz.getName() + " on the " + "field '" + idField
	+ "' returned more than one object." );
	}

	pm.getFetchPlan().addGroup( fetchGroup );

	Object object = pm.detachCopy( result.iterator().next() );

	tx.commit();

	return object;
	}
	finally
	{
	rollbackIfActive( tx );
	}
	}

	public static List getAllObjectsDetached( PersistenceManager pm, Class clazz )
	{
	return getAllObjectsDetached( pm, clazz, null );
	}

	public static List getAllObjectsDetached( PersistenceManager pm, Class clazz, String fetchGroup )
	{
	return getAllObjectsDetached( pm, clazz, null, fetchGroup );
	}

	public static List getAllObjectsDetached( PersistenceManager pm, Class clazz, String ordering, String fetchGroup )
	{
	if ( fetchGroup != null )
	{
	return getAllObjectsDetached( pm, clazz, ordering, Collections.singletonList( fetchGroup ) );
	}
	else
	{
	return getAllObjectsDetached( pm, clazz, ordering, Collections.EMPTY_LIST );
	}
	}

	public static List getAllObjectsDetached( PersistenceManager pm, Class clazz, String ordering,
	List/* <String> */fetchGroups )
	{
	Transaction tx = pm.currentTransaction();

	try
	{
	tx.begin();

	Extent extent = pm.getExtent( clazz, true );

	Query query = pm.newQuery( extent );

	if ( ordering != null )
	{
	query.setOrdering( ordering );
	}

	for ( Iterator i = fetchGroups.iterator(); i.hasNext(); )
	{
	pm.getFetchPlan().addGroup( (String) i.next() );
	}

	List result = (List) query.execute();

	result = (List) pm.detachCopyAll( result );

	tx.commit();

	return result;
	}
	finally
	{
	rollbackIfActive( tx );
	}
	}

	public static void attachAndDelete( PersistenceManager pm, Object object )
	{
	Transaction tx = pm.currentTransaction();

	try
	{
	tx.begin();

	pm.makePersistent( object );

	pm.deletePersistent( object );

	tx.commit();
	}
	finally
	{
	rollbackIfActive( tx );
	}
	}

	public static void rollbackIfActive( Transaction tx )
	{
	PersistenceManager pm = tx.getPersistenceManager();

	try
	{
	if ( tx.isActive() )
	{
	tx.rollback();
	}
	}
	finally
	{
	closePersistenceManager( pm );
	}
	}

	public static void closePersistenceManager( PersistenceManager pm )
	{
	try
	{
	pm.close();
	}
	catch ( JDOUserException e )
	{
	// ignore
	}
	}

	public static void removeAll( PersistenceManager pm, Class aClass )
	{
	Transaction tx = pm.currentTransaction();

	try
	{
	tx.begin();

	Query query = pm.newQuery( aClass );
	query.deletePersistentAll();

	tx.commit();
	}
	finally
	{
	rollbackIfActive( tx );
	}
	}
	}