Hibernate example source code file (OrderByFragmentParser.java)

This example Hibernate source code file (OrderByFragmentParser.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Hibernate tags/keywords

arraylist, ast, ast, orderbyfragmentparser, orderingspecification, override, override, sort_spec, sortspecification, sortspecification, sqlfunction, string, string, translationcontext, util

The Hibernate OrderByFragmentParser.java source code

/*
 * 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
 * Boston, MA  02110-1301  USA
 *
 */
package org.hibernate.sql.ordering.antlr;

import java.util.ArrayList;

import org.hibernate.internal.CoreMessageLogger;
import org.hibernate.dialect.function.SQLFunction;
import org.hibernate.internal.util.StringHelper;
import org.hibernate.sql.Template;
import org.jboss.logging.Logger;
import antlr.CommonAST;
import antlr.TokenStream;
import antlr.collections.AST;

/**
 * Extension of the Antlr-generated parser for the purpose of adding our custom parsing behavior.
 *
 * @author Steve Ebersole
 */
public class OrderByFragmentParser extends GeneratedOrderByFragmentParser {

    private static final CoreMessageLogger LOG = Logger.getMessageLogger(CoreMessageLogger.class, OrderByFragmentParser.class.getName());

	private final TranslationContext context;

	public OrderByFragmentParser(TokenStream lexer, TranslationContext context) {
		super( lexer );
		super.setASTFactory( new Factory() );
		this.context = context;
	}


	// handle trace logging ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    private int traceDepth = 0;


	@Override
    public void traceIn(String ruleName) {
		if ( inputState.guessing > 0 ) {
			return;
		}
		String prefix = StringHelper.repeat( '-', (traceDepth++ * 2) ) + "-> ";
        LOG.trace(prefix + ruleName);
	}

	@Override
    public void traceOut(String ruleName) {
		if ( inputState.guessing > 0 ) {
			return;
		}
		String prefix = "<-" + StringHelper.repeat( '-', (--traceDepth * 2) ) + " ";
        LOG.trace(prefix + ruleName);
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
    protected void trace(String msg) {
        LOG.trace(msg);
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
    protected AST quotedIdentifier(AST ident) {
		return getASTFactory().create(
				OrderByTemplateTokenTypes.IDENT,
				Template.TEMPLATE + "." + context.getDialect().quote( '`' + ident.getText() + '`' )
		);
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
    protected AST quotedString(AST ident) {
		return getASTFactory().create( OrderByTemplateTokenTypes.IDENT, context.getDialect().quote( ident.getText() ) );
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
    protected boolean isFunctionName(AST ast) {
		AST child = ast.getFirstChild();
		// assume it is a function if it has parameters
		if ( child != null && "{param list}".equals( child.getText() ) ) {
			return true;
		}

		final SQLFunction function = context.getSqlFunctionRegistry().findSQLFunction( ast.getText() );
		if ( function == null ) {
			return false;
		}

		// if function.hasParenthesesIfNoArguments() is true, then assume
		// ast.getText() is not a function.
		return ! function.hasParenthesesIfNoArguments();
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
    protected AST resolveFunction(AST ast) {
		AST child = ast.getFirstChild();
		if ( child != null ) {
			assert "{param list}".equals(  child.getText() );
			child = child.getFirstChild();
		}

		final String functionName = ast.getText();
		final SQLFunction function = context.getSqlFunctionRegistry().findSQLFunction( functionName );
		if ( function == null ) {
			String text = functionName;
			if ( child != null ) {
				text += '(';
				while ( child != null ) {
					text += child.getText();
					child = child.getNextSibling();
					if ( child != null ) {
						text += ", ";
					}
				}
				text += ')';
			}
			return getASTFactory().create( OrderByTemplateTokenTypes.IDENT, text );
		}
		else {
			ArrayList expressions = new ArrayList();
			while ( child != null ) {
				expressions.add( child.getText() );
				child = child.getNextSibling();
			}
			final String text = function.render( null, expressions, context.getSessionFactory() );
			return getASTFactory().create( OrderByTemplateTokenTypes.IDENT, text );
		}
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
    protected AST resolveIdent(AST ident) {
		String text = ident.getText();
		String[] replacements;
		try {
			replacements = context.getColumnMapper().map( text );
		}
		catch( Throwable t ) {
			replacements = null;
		}

		if ( replacements == null || replacements.length == 0 ) {
			return getASTFactory().create( OrderByTemplateTokenTypes.IDENT, Template.TEMPLATE + "." + text );
		}
		else if ( replacements.length == 1 ) {
			return getASTFactory().create( OrderByTemplateTokenTypes.IDENT, Template.TEMPLATE + "." + replacements[0] );
		}
		else {
			final AST root = getASTFactory().create( OrderByTemplateTokenTypes.IDENT_LIST, "{ident list}" );
			for ( int i = 0; i < replacements.length; i++ ) {
				final String identText = Template.TEMPLATE + '.' + replacements[i];
				root.addChild( getASTFactory().create( OrderByTemplateTokenTypes.IDENT, identText ) );
			}
			return root;
		}
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
    protected AST postProcessSortSpecification(AST sortSpec) {
		assert SORT_SPEC == sortSpec.getType();
		SortSpecification sortSpecification = ( SortSpecification ) sortSpec;
		AST sortKey = sortSpecification.getSortKey();
		if ( IDENT_LIST == sortKey.getFirstChild().getType() ) {
			AST identList = sortKey.getFirstChild();
			AST ident = identList.getFirstChild();
			AST holder = new CommonAST();
			do {
				holder.addChild(
						createSortSpecification(
								ident,
								sortSpecification.getCollation(),
								sortSpecification.getOrdering()
						)
				);
				ident = ident.getNextSibling();
			} while ( ident != null );
			sortSpec = holder.getFirstChild();
		}
		return sortSpec;
	}

	private SortSpecification createSortSpecification(
			AST ident,
			CollationSpecification collationSpecification,
			OrderingSpecification orderingSpecification) {
		AST sortSpecification = getASTFactory().create( SORT_SPEC, "{{sort specification}}" );
		AST sortKey = getASTFactory().create( SORT_KEY, "{{sort key}}" );
		AST newIdent = getASTFactory().create( ident.getType(), ident.getText() );
		sortKey.setFirstChild( newIdent );
		sortSpecification.setFirstChild( sortKey );
		if ( collationSpecification != null ) {
			sortSpecification.addChild( collationSpecification );
		}
		if ( orderingSpecification != null ) {
			sortSpecification.addChild( orderingSpecification );
		}
		return ( SortSpecification ) sortSpecification;
	}
}