/*******************************************************************************
* Copyright (c) 2011, 2012 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:
* 01/25/2011-2.3 Guy Pelletier
* - 333913: @OrderBy and <order-by/> without arguments should order by primary
* 03/24/2011-2.3 Guy Pelletier
* - 337323: Multi-tenant with shared schema support (part 1)
******************************************************************************/
package org.eclipse.persistence.internal.jpa.metadata.mappings;
import java.util.List;
import java.util.StringTokenizer;
import org.eclipse.persistence.exceptions.ValidationException;
import org.eclipse.persistence.internal.jpa.metadata.MetadataDescriptor;
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.mappings.MappingAccessor;
import org.eclipse.persistence.internal.jpa.metadata.accessors.objects.MetadataAnnotation;
import org.eclipse.persistence.internal.jpa.metadata.accessors.objects.MetadataClass;
import org.eclipse.persistence.mappings.CollectionMapping;
/**
* Object to hold onto order by metadata.
*
* 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 EclipseLink 2.3
*/
public class OrderByMetadata extends ORMetadata {
// Order by constants
private static final String ASCENDING = "ASC";
private static final String DESCENDING = "DESC";
private String m_value;
/**
* INTERNAL:
* Used for XML loading.
*/
public OrderByMetadata() {
super("<order-by>");
}
/**
* INTERNAL:
* Used for annotation loading.
*/
public OrderByMetadata(MetadataAnnotation orderBy, MetadataAccessor accessor) {
super(orderBy, accessor);
m_value = (String) orderBy.getAttributeString("value");
}
/**
* INTERNAL:
* For merging and overriding to work properly, all ORMetadata must be able
* to compare themselves for metadata equality.
*/
@Override
public boolean equals(Object objectToCompare) {
if (objectToCompare instanceof OrderByMetadata) {
OrderByMetadata orderBy = (OrderByMetadata) objectToCompare;
return valuesMatch(m_value, orderBy.getValue());
}
return false;
}
/**
* INTERNAL:
* Used for OX mapping.
*/
public String getValue() {
return m_value;
}
/**
* INTERNAL:
* Process an order by value (if specified) for the given collection
* mapping. Order by specifies the ordering of the elements of a collection
* valued association at the point when the association is retrieved.
*
* The syntax of the value ordering element is an orderby_list, as follows:
*
* orderby_list ::= orderby_item [, orderby_item]*
* orderby_item ::= property_or_field_name [ASC | DESC]
*
* When ASC or DESC is not specified, ASC is assumed.
*
* If the ordering element is not specified, ordering by the primary key
* of the associated entity is assumed.
*
* The property or field name must correspond to that of a persistent
* property or field of the associated class. The properties or fields
* used in the ordering must correspond to columns for which comparison
* operators are supported.
*/
public void process(CollectionMapping mapping, MetadataDescriptor referenceDescriptor, MetadataClass javaClass) {
if (m_value != null && ! m_value.equals("")) {
StringTokenizer commaTokenizer = new StringTokenizer(m_value, ",");
while (commaTokenizer.hasMoreTokens()) {
StringTokenizer spaceTokenizer = new StringTokenizer(commaTokenizer.nextToken());
String propertyOrFieldName = spaceTokenizer.nextToken();
MappingAccessor referenceAccessor = referenceDescriptor.getMappingAccessor(propertyOrFieldName);
if (referenceAccessor == null) {
throw ValidationException.invalidOrderByValue(propertyOrFieldName, referenceDescriptor.getJavaClass(), getAccessibleObjectName(), javaClass);
}
String attributeName = referenceAccessor.getAttributeName();
String ordering = (spaceTokenizer.hasMoreTokens()) ? spaceTokenizer.nextToken() : ASCENDING;
if (referenceAccessor.isEmbedded()) {
for (String orderByAttributeName : referenceDescriptor.getOrderByAttributeNames()) {
mapping.addAggregateOrderBy(m_value, orderByAttributeName, ordering.equals(DESCENDING));
}
} else if (referenceAccessor.getClassAccessor().isEmbeddableAccessor()) {
// We have a specific order by from an embeddable, we need to rip off
// the last bit of a dot notation if specified and pass in the chained
// string names of the nested embeddables only.
String embeddableChain = m_value;
if (embeddableChain.contains(".")) {
embeddableChain = embeddableChain.substring(0, embeddableChain.lastIndexOf("."));
}
mapping.addAggregateOrderBy(embeddableChain, attributeName, ordering.equals(DESCENDING));
} else {
mapping.addOrderBy(attributeName, ordering.equals(DESCENDING));
}
}
} else {
// Default to the primary key field name(s).
List<String> orderByAttributes = referenceDescriptor.getIdOrderByAttributeNames();
if (referenceDescriptor.hasEmbeddedId()) {
String embeddedIdAttributeName = referenceDescriptor.getEmbeddedIdAttributeName();
for (String orderByAttribute : orderByAttributes) {
mapping.addAggregateOrderBy(embeddedIdAttributeName, orderByAttribute, false);
}
} else {
for (String orderByAttribute : orderByAttributes) {
mapping.addOrderBy(orderByAttribute, false);
}
}
}
}
/**
* INTERNAL:
* Used for OX mapping.
*/
public void setValue(String value) {
m_value = value;
}
}