org.hibernate.sql.ordering.antlr.SortSpecification Maven / Gradle / Ivy
/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2008, Red Hat Middleware LLC or third-party contributors as
* indicated by the @author tags or express copyright attribution
* statements applied by the authors. All third-party contributions are
* distributed under license by Red Hat Middleware LLC.
*
* This copyrighted material is made available to anyone wishing to use, modify,
* copy, or redistribute it subject to the terms and conditions of the GNU
* Lesser General Public License, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this distribution; if not, write to:
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor
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*
*/
package org.hibernate.sql.ordering.antlr;
import antlr.collections.AST;
/**
* Models each sorting exprersion.
*
* @author Steve Ebersole
*/
public class SortSpecification extends NodeSupport {
/**
* Locate the specified {@link SortKey}.
*
* @return The sort key.
*/
public SortKey getSortKey() {
return ( SortKey ) getFirstChild();
}
/**
* Locate the specified collation specification, if one.
*
* @return The collation specification, or null if none was specified.
*/
public CollationSpecification getCollation() {
AST possible = getSortKey().getNextSibling();
return possible != null && OrderByTemplateTokenTypes.COLLATE == possible.getType()
? ( CollationSpecification ) possible
: null;
}
/**
* Locate the specified ordering specification, if one.
*
* @return The ordering specification, or null if none was specified.
*/
public OrderingSpecification getOrdering() {
// IMPL NOTE : the ordering-spec would be either the 2nd or 3rd child (of the overall sort-spec), if it existed,
// depending on whether a collation-spec was specified.
AST possible = getSortKey().getNextSibling();
if ( possible == null ) {
// There was no sort-spec parts specified other then the sort-key so there can be no ordering-spec...
return null;
}
if ( OrderByTemplateTokenTypes.COLLATE == possible.getType() ) {
// the 2nd child was a collation-spec, so we need to check the 3rd child instead.
possible = possible.getNextSibling();
}
return possible != null && OrderByTemplateTokenTypes.ORDER_SPEC == possible.getType()
? ( OrderingSpecification ) possible
: null;
}
}