/*******************************************************************************
 * Copyright (c) 2008, 2009 Sun Microsystems. 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 2.0 - Version 2.0 (October 1, 2009)
 *     Specification available from http://jcp.org/en/jsr/detail?id=317
 *
 ******************************************************************************/
package javax.persistence;

import java.lang.annotation.Target;
import java.lang.annotation.Retention;
import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.RetentionPolicy.RUNTIME;

/**
 * Supports composite map keys that reference entities.  
 * <p> The <code>MapKeyJoinColumns</code> annotation groups
 * <code>MapKeyJoinColumn</code> annotations.  When the
 * <code>MapKeyJoinColumns</code> annotation is used, both the
 * <code>name</code> and the <code>referencedColumnName</code>
 * elements must be specified in each of the grouped
 * <code>MapKeyJoinColumn</code> annotations.
 * 
 * @see MapKeyJoinColumn
 * 
 * @since Java Persistence 2.0
 */
@Target( { METHOD, FIELD })
@Retention(RUNTIME)
public @interface MapKeyJoinColumns {
	/**
	 * (Required) The map key join columns that are used to map to the entity
	 * that is the map key.
	 */
	MapKeyJoinColumn[] value();
}