javax.persistence.AttributeConverter Maven / Gradle / Ivy
/*
* Copyright (c) 2008, 2009, 2011 Oracle, Inc. 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.
*/
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
* @since Java Persistence 2.1
*/
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
*/
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
*/
X convertToEntityAttribute(Y dbData);
}