javax.persistence.AttributeConverter Maven / Gradle / Ivy
/*******************************************************************************
* Copyright (c) 2011 - 2013 Oracle Corporation. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
* which accompanies this distribution.
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
* and the Eclipse Distribution License is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* Contributors:
* Linda DeMichiel - Java Persistence 2.1
*
******************************************************************************/
package javax.persistence;
/**
* A class that implements this interface can be used to convert
* entity attribute state into database column representation
* and back again.
* Note that the X and Y types may be the same Java type.
*
* @param the type of the entity attribute
* @param the type of the database column
*/
public interface AttributeConverter {
/**
* Converts the value stored in the entity attribute into the
* data representation to be stored in the database.
*
* @param attribute the entity attribute value to be converted
* @return the converted data to be stored in the database
* column
*/
public Y convertToDatabaseColumn (X attribute);
/**
* Converts the data stored in the database column into the
* value to be stored in the entity attribute.
* Note that it is the responsibility of the converter writer to
* specify the correct dbData type for the corresponding
* column for use by the JDBC driver: i.e., persistence providers are
* not expected to do such type conversion.
*
* @param dbData the data from the database column to be
* converted
* @return the converted value to be stored in the entity
* attribute
*/
public X convertToEntityAttribute (Y dbData);
}