package org.apache.ojb.broker.metadata.fieldaccess;
/* Copyright 2002-2004 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.core.PersistenceBrokerConfiguration;
import org.apache.ojb.broker.metadata.MetadataException;
import org.apache.ojb.broker.util.ClassHelper;
import org.apache.ojb.broker.util.configuration.ConfigurationException;
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;
/**
* @author <a href="mailto:thma@apache.org">Thomas Mahler<a>
* @version $Id: PersistentFieldFactory.java,v 1.11 2004/04/04 23:53:35 brianm Exp $
*/
public class PersistentFieldFactory
{
private static Logger log = LoggerFactory.getLogger(PersistentFieldFactory.class);
private static final Class DEFAULT_PERSISTENT_FIELD_IMPL = PersistentFieldDirectAccessImpl.class;
private static final Class[] METHOD_PARAMETER_TYPES = {Class.class, String.class};
private static boolean usesAccessorsAndMutators = false;
private static boolean usesAccessorsAndMutatorsCheck = false;
/**
* @throws MetadataException if an erros occours when creating the PersistenteField
*/
public static PersistentField createPersistentField(Class attributeType, String attributeName)
{
return createPersistentField(null,attributeType,attributeName);
}
public static PersistentField createPersistentField(String persistentFieldClassName, Class attributeType, String attributeName)
{
try
{
if (persistentFieldClassName == null)
{
synchronized (PersistentFieldFactory.class)
{
persistentFieldClassName = getDefaultPersistentFieldClassName();
}
}
Object[] args = {attributeType, attributeName};
PersistentField pf = (PersistentField) ClassHelper.newInstance(persistentFieldClassName, METHOD_PARAMETER_TYPES, args);
return pf;
}
catch (Exception ex)
{
throw new MetadataException("Error creating PersistentField: " +
attributeType.getName() + ", " + attributeName, ex);
}
}
public static boolean usesAccessorsAndMutators()
{
boolean retval = false;
if (usesAccessorsAndMutatorsCheck)
retval = usesAccessorsAndMutators;
else
{
String className = getDefaultPersistentFieldClassName();
PersistentField field = null;
try
{
field = (PersistentField) ClassHelper.newInstance(className);
usesAccessorsAndMutators = field.usesAccessorsAndMutators();
retval = usesAccessorsAndMutators;
}
catch (Exception e)
{
log.error("Cannot verify 'usesAccessorsAndMutators' attribute for class " + className, e);
}
finally
{
usesAccessorsAndMutatorsCheck = true;
}
}
return retval;
}
private static String getDefaultPersistentFieldClassName()
{
try
{
PersistenceBrokerConfiguration config =
(PersistenceBrokerConfiguration) OjbConfigurator.getInstance().getConfigurationFor(
null);
Class clazz = config.getPersistentFieldClass();
return clazz.getName();
}
catch (ConfigurationException e)
{
log.error("Cannot look-up PersistentField class, use default implementation instead", e);
return DEFAULT_PERSISTENT_FIELD_IMPL.getName();
}
}
}