/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2009 by Red Hat Inc and/or its affiliates or by
 * third-party contributors as indicated by either @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.jpa.criteria.expression;

import java.io.Serializable;

import org.hibernate.jpa.criteria.CriteriaBuilderImpl;
import org.hibernate.jpa.criteria.ParameterRegistry;
import org.hibernate.jpa.criteria.ValueHandlerFactory;
import org.hibernate.jpa.criteria.compile.RenderingContext;

Represents a literal expression.
Author:Steve Ebersole
/** * Represents a literal expression. * * @author Steve Ebersole */
public class LiteralExpression<T> extends ExpressionImpl<T> implements Serializable { private Object literal; @SuppressWarnings({ "unchecked" }) public LiteralExpression(CriteriaBuilderImpl criteriaBuilder, T literal) { this( criteriaBuilder, (Class<T>) determineClass( literal ), literal ); } private static Class determineClass(Object literal) { return literal == null ? null : literal.getClass(); } public LiteralExpression(CriteriaBuilderImpl criteriaBuilder, Class<T> type, T literal) { super( criteriaBuilder, type ); this.literal = literal; } @SuppressWarnings({ "unchecked" }) public T getLiteral() { return (T) literal; } public void registerParameters(ParameterRegistry registry) { // nothing to do } @SuppressWarnings({ "unchecked" }) public String render(RenderingContext renderingContext) { if ( ValueHandlerFactory.isNumeric( literal ) ) { return ValueHandlerFactory.determineAppropriateHandler( (Class) literal.getClass() ).render( literal ); } // else... final String parameterName = renderingContext.registerLiteralParameterBinding( getLiteral(), getJavaType() ); return ':' + parameterName; } @SuppressWarnings({ "unchecked" }) public String renderProjection(RenderingContext renderingContext) { // some drivers/servers do not like parameters in the select clause final ValueHandlerFactory.ValueHandler handler = ValueHandlerFactory.determineAppropriateHandler( literal.getClass() ); if ( ValueHandlerFactory.isCharacter( literal ) ) { return '\'' + handler.render( literal ) + '\''; } else { return handler.render( literal ); } } @Override @SuppressWarnings({ "unchecked" }) protected void resetJavaType(Class targetType) { super.resetJavaType( targetType ); ValueHandlerFactory.ValueHandler valueHandler = getValueHandler(); if ( valueHandler == null ) { valueHandler = ValueHandlerFactory.determineAppropriateHandler( targetType ); forceConversion( valueHandler ); } if ( valueHandler != null ) { literal = valueHandler.convert( literal ); } } }