jpa/org.eclipse.persistence.jpa/src/main/java/org/eclipse/persistence/internal/jpa/metadata/queries/EntityResultMetadata.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
//     03/24/2011-2.3 Guy Pelletier
//       - 337323: Multi-tenant with shared schema support (part 1)
//     02/08/2012-2.4 Guy Pelletier
//       - 350487: JPA 2.1 Specification defined support for Stored Procedure Calls
//     06/20/2012-2.5 Guy Pelletier
//       - 350487: JPA 2.1 Specification defined support for Stored Procedure Calls
//     11/19/2012-2.5 Guy Pelletier
//       - 389090: JPA 2.1 DDL Generation Support (foreign key metadata support)
package org.eclipse.persistence.internal.jpa.metadata.queries;

import java.util.List;
import java.util.ArrayList;

import org.eclipse.persistence.internal.helper.DatabaseField;
import org.eclipse.persistence.internal.jpa.metadata.ORMetadata;
import org.eclipse.persistence.internal.jpa.metadata.accessors.MetadataAccessor;
import org.eclipse.persistence.internal.jpa.metadata.accessors.objects.MetadataAccessibleObject;
import org.eclipse.persistence.internal.jpa.metadata.accessors.objects.MetadataAnnotation;
import org.eclipse.persistence.internal.jpa.metadata.accessors.objects.MetadataClass;
import org.eclipse.persistence.internal.jpa.metadata.xml.XMLEntityMappings;

import org.eclipse.persistence.queries.EntityResult;

/**
 * INTERNAL:
 * Object to hold onto an entity result metadata.
 *
 * Key notes:
 * - any metadata mapped from XML to this class must be compared in the
 *   equals method.
 * - all metadata mapped from XML must be initialized in the initXMLObject
 *   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 EntityResultMetadata extends ORMetadata {
    private MetadataClass m_entityClass; // Required in both XML and annotations.
    private List<FieldResultMetadata> m_fieldResults = new ArrayList<FieldResultMetadata>();
    private String m_discriminatorColumn;
    private String m_entityClassName;

    /**
     * INTERNAL:
     * Used for XML loading.
     */
    public EntityResultMetadata() {
        super("<entity-result>");
    }

    /**
     * INTERNAL:
     * Used for annotation loading.
     */
    public EntityResultMetadata(MetadataAnnotation entityResult, MetadataAccessor accessor) {
        super(entityResult, accessor);

        m_entityClass = getMetadataClass(entityResult.getAttributeString("entityClass"));
        m_discriminatorColumn = entityResult.getAttributeString("discriminatorColumn");

        for (Object fieldResult : entityResult.getAttributeArray("fields")) {
            m_fieldResults.add(new FieldResultMetadata((MetadataAnnotation) fieldResult, accessor));
        }
    }

    /**
     * INTERNAL:
     * Used for result class processing.
     */
    public EntityResultMetadata(MetadataClass entityClass, MetadataAccessibleObject accessibleObject) {
        m_entityClass = entityClass;
        setAccessibleObject(accessibleObject);
    }

    /**
     * INTERNAL:
     */
    @Override
    public boolean equals(Object objectToCompare) {
        if (objectToCompare instanceof EntityResultMetadata) {
            EntityResultMetadata entityResult = (EntityResultMetadata) objectToCompare;

            if (! valuesMatch(m_entityClass, entityResult.getEntityClass())) {
                return false;
            }

            if (! valuesMatch(m_fieldResults, entityResult.getFieldResults())) {
                return false;
            }

            return valuesMatch(m_discriminatorColumn, entityResult.getDiscriminatorColumn());
        }

        return false;
    }

    @Override
    public int hashCode() {
        int result = m_entityClass != null ? m_entityClass.hashCode() : 0;
        result = 31 * result + (m_fieldResults != null ? m_fieldResults.hashCode() : 0);
        result = 31 * result + (m_discriminatorColumn != null ? m_discriminatorColumn.hashCode() : 0);
        return result;
    }

    /**
     * INTERNAL:
     * Used for OX mapping.
     */
    public String getDiscriminatorColumn() {
        return m_discriminatorColumn;
    }

    /**
     * INTERNAL:
     */
    public MetadataClass getEntityClass() {
        return m_entityClass;
    }

    /**
     * INTERNAL:
     * Used for OX mapping.
     */
    public String getEntityClassName() {
        return m_entityClassName;
    }

    /**
     * INTERNAL:
     * Used for OX mapping.
     */
    public List<FieldResultMetadata> getFieldResults() {
        return m_fieldResults;
    }

    /**
     * INTERNAL:
     */
    @Override
    public void initXMLObject(MetadataAccessibleObject accessibleObject, XMLEntityMappings entityMappings) {
        super.initXMLObject(accessibleObject, entityMappings);

        // Initialize lists of ORMetadata objects.
        initXMLObjects(m_fieldResults, accessibleObject);

        m_entityClass = initXMLClassName(m_entityClassName);
    }

    /**
     * INTERNAL:
     * Process the entity result for the given sql result set mapping.
     */
    public EntityResult process() {
        // Create a new entity result.
        EntityResult entityResult = new EntityResult(getJavaClassName(getEntityClass()));

        // Process the field results.
        for (FieldResultMetadata fieldResult : getFieldResults()) {
            entityResult.addFieldResult(fieldResult.process());
        }

        // Process the discriminator value;
        if (getDiscriminatorColumn() != null) {
            DatabaseField discriminatorField = new DatabaseField();

            // Process the name (taking into consideration delimiters etc.)
            setFieldName(discriminatorField, getDiscriminatorColumn());

            // Set the discriminator column on the entity result.
            entityResult.setDiscriminatorColumn(discriminatorField);
        }

        // Return the entity result to the caller.
        return entityResult;
    }

    /**
     * INTERNAL:
     * Used for OX mapping.
     */
    public void setDiscriminatorColumn(String discriminatorColumn) {
        m_discriminatorColumn = discriminatorColumn;
    }

    /**
     * INTERNAL:
     */
    public void setEntityClass(MetadataClass entityClass) {
        m_entityClass = entityClass;
    }

    /**
     * INTERNAL:
     * Used for OX mapping.
     */
    public void setEntityClassName(String entityClassName) {
        m_entityClassName = entityClassName;
    }

    /**
     * INTERNAL:
     * Used for OX mapping.
     */
    public void setFieldResults(List<FieldResultMetadata> fieldResults) {
        m_fieldResults = fieldResults;
    }
}