jpa/org.eclipse.persistence.jpa/src/main/java/org/eclipse/persistence/internal/jpa/metadata/columns/PrimaryKeyJoinColumnMetadata.java

/*
 * Copyright (c) 1998, 2020 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 v. 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0,
 * or the Eclipse Distribution License v. 1.0 which is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
 */

// Contributors:
//     Oracle - initial API and implementation from Oracle TopLink
//     05/16/2008-1.0M8 Guy Pelletier
//       - 218084: Implement metadata merging functionality between mapping files
//     06/09/2009-2.0 Guy Pelletier
//       - 249037: JPA 2.0 persisting list item index
//     04/27/2010-2.1 Guy Pelletier
//       - 309856: MappedSuperclasses from XML are not being initialized properly
//     03/24/2011-2.3 Guy Pelletier
//       - 337323: Multi-tenant with shared schema support (part 1)
package org.eclipse.persistence.internal.jpa.metadata.columns;

import org.eclipse.persistence.internal.jpa.metadata.MetadataProject;
import org.eclipse.persistence.internal.jpa.metadata.accessors.MetadataAccessor;
import org.eclipse.persistence.internal.jpa.metadata.accessors.objects.MetadataAnnotation;

/**
 * INTERNAL:
 * Object to process JPA primary key join columns EclipseLink database fields.
 *
 * Key notes:
 * - any metadata mapped from XML to this class must be compared in the
 *   equals method.
 * - when loading from annotations, the constructor accepts the metadata
 *   accessor this metadata was loaded from. Used it to look up any
 *   'companion' annotation needed for processing.
 * - methods should be preserved in alphabetical order.
 *
 * @author Guy Pelletier
 * @since TopLink EJB 3.0 Reference Implementation
 */
public class PrimaryKeyJoinColumnMetadata extends RelationalColumnMetadata {
    /**
     * INTERNAL:
     * Used for XML loading.
     */
    public PrimaryKeyJoinColumnMetadata() {
        super("<primary-key-join-column>");
    }

    /**
     * INTERNAL:
     * Used for annotation loading.
     */
    public PrimaryKeyJoinColumnMetadata(MetadataProject project) {
        this();
        this.m_project = project;
    }

    /**
     * INTERNAL:
     * Used for annotation loading.
     */
    public PrimaryKeyJoinColumnMetadata(MetadataAnnotation primaryKeyJoinColumn, MetadataAccessor accessor) {
        super(primaryKeyJoinColumn, accessor);
    }

    /**
     * INTERNAL:
     */
    @Override
    public boolean equals(Object objectToCompare) {
        return super.equals(objectToCompare) && objectToCompare instanceof PrimaryKeyJoinColumnMetadata;
    }

    @Override
    public int hashCode() {
        return super.hashCode();
    }
}