http://www.avaje.org/java8-parent/persistence-api: For open source java artifacts.
  • Rob Bygrave 
/*
 * 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.

Params:
  • X – the type of the entity attribute
  • Y – the type of the database column
Since:Java Persistence 2.1
/**
 * 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 X the type of the entity attribute
 * @param Y the type of the database column
 * @since Java Persistence 2.1
 */
public interface AttributeConverter<X, Y> {
  
Converts the value stored in the entity attribute into the
data representation to be stored in the database.

Params:
  • attribute – the entity attribute value to be converted
Returns:the converted data to be stored in the database column
/**
   * 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.

Params:
  • dbData – the data from the database column to be converted
Returns:the converted value to be stored in the entity 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);
}