/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2008 Red Hat Inc. 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 Inc.
*
* 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
* Boston, MA 02110-1301 USA
*/
package org.hibernate.sql.ordering.antlr;
import java.io.StringReader;
import java.util.Set;
import org.hibernate.HibernateException;
import org.hibernate.hql.internal.ast.util.ASTPrinter;
import org.jboss.logging.Logger;
/**
* A translator for order-by mappings, whether specified by hbm.xml files, Hibernate
* {@link org.hibernate.annotations.OrderBy} annotation or JPA {@link javax.persistence.OrderBy} annotation.
*
* @author Steve Ebersole
*/
public class OrderByFragmentTranslator {
private static final Logger LOG = Logger.getLogger( OrderByFragmentTranslator.class.getName() );
/**
* Perform the translation of the user-supplied fragment, returning the translation.
* <p/>
* The important distinction to this split between (1) translating and (2) resolving aliases is that
* both happen at different times
*
*
* @param context Context giving access to delegates needed during translation.
* @param fragment The user-supplied order-by fragment
*
* @return The translation.
*/
public static OrderByTranslation translate(TranslationContext context, String fragment) {
GeneratedOrderByLexer lexer = new GeneratedOrderByLexer( new StringReader( fragment ) );
// Perform the parsing (and some analysis/resolution). Another important aspect is the collection
// of "column references" which are important later to seek out replacement points in the
// translated fragment.
OrderByFragmentParser parser = new OrderByFragmentParser( lexer, context );
try {
parser.orderByFragment();
}
catch ( HibernateException e ) {
throw e;
}
catch ( Throwable t ) {
throw new HibernateException( "Unable to parse order-by fragment", t );
}
if ( LOG.isTraceEnabled() ) {
ASTPrinter printer = new ASTPrinter( OrderByTemplateTokenTypes.class );
LOG.trace( printer.showAsString( parser.getAST(), "--- {order-by fragment} ---" ) );
}
// Render the parsed tree to text.
OrderByFragmentRenderer renderer = new OrderByFragmentRenderer( context.getSessionFactory() );
try {
renderer.orderByFragment( parser.getAST() );
}
catch ( HibernateException e ) {
throw e;
}
catch ( Throwable t ) {
throw new HibernateException( "Unable to render parsed order-by fragment", t );
}
return new StandardOrderByTranslationImpl( renderer.getRenderedFragment(), parser.getColumnReferences() );
}
public static class StandardOrderByTranslationImpl implements OrderByTranslation {
private final String sqlTemplate;
private final Set<String> columnReferences;
public StandardOrderByTranslationImpl(String sqlTemplate, Set<String> columnReferences) {
this.sqlTemplate = sqlTemplate;
this.columnReferences = columnReferences;
}
@Override
public String injectAliases(OrderByAliasResolver aliasResolver) {
String sql = sqlTemplate;
for ( String columnReference : columnReferences ) {
final String replacementToken = "{" + columnReference + "}";
sql = sql.replace(
replacementToken,
aliasResolver.resolveTableAlias( columnReference ) + '.' + columnReference
);
}
return sql;
}
}
}