/*
* JBoss, Home of Professional Open Source.
* Copyright 2008, Red Hat Middleware LLC, and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.ejb.plugins.cmp.jdbc;
/**
* Generally, implementations of this interface map instances of one Java type
* into instances of another Java type.
* Mappers are used in cases when instances of "enum" types are used as CMP
* field values. In this case, a mapper represents a mediator and translates
* instances of "enum" to some id when that can be stored in a column when storing
* data and back from id to "enum" instance when data is loaded.
*
* @author <a href="mailto:alex@jboss.org">Alex Loubyansky</a>
*/
public interface Mapper
{
/**
* This method is called when CMP field is stored.
* @param fieldValue - CMP field value
* @return column value.
*/
Object toColumnValue(Object fieldValue);
/**
* This method is called when CMP field is loaded.
* @param columnValue - loaded column value.
* @return CMP field value.
*/
Object toFieldValue(Object columnValue);
}