/*******************************************************************************
* Copyright (c) 2011, 2015 Oracle and/or its affiliates. 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:
* dmccann - September 14/2010 - 2.2 - Initial implementation
******************************************************************************/
package org.eclipse.persistence.oxm.annotations;
import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;
/**
* <p>XmlKey is used to mark a property as a key, to be referenced using a key-based mapping via {@code XmlJoinNode}. This is
* similar to the {@code XmlID} annotation, but doesn't require the property be bound to the schema type ID. XmlKey is
* typically used in the composite key use case, since only 1 property can be annotated with the XmlID annotation.
* </p>
*
* <p><b>Example:</b>
* <pre>
* @XmlRootElement
* @XmlAccessorType(XmlAccessType.FIELD)
* public class Employee {
*
* @XmlKey
* public String id;
*
* @XmlKey
* public String department;
*
* @XmlJoinNodes({
* @XmlJoinNode(xmlPath="manager/id/text()", referencedXmlPath="id/text()"),
* @XmlJoinNode(xmlPath="manager/dept/text()", referencedXmlPath="department/text()")
* })
* public Employee manager;
* }
* </pre>
*
* @see XmlJoinNode
* @see XmlJoinNodes
*/
@Target({METHOD, FIELD})
@Retention(RUNTIME)
public @interface XmlKey {}