/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
 * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
 */
package org.hibernate.query.criteria.internal.path;

import java.io.Serializable;
import javax.persistence.metamodel.Attribute;
import javax.persistence.metamodel.Bindable;
import javax.persistence.metamodel.EmbeddableType;
import javax.persistence.metamodel.IdentifiableType;
import javax.persistence.metamodel.ManagedType;
import javax.persistence.metamodel.SingularAttribute;

import org.hibernate.query.criteria.internal.CriteriaBuilderImpl;
import org.hibernate.query.criteria.internal.PathSource;
import org.hibernate.query.criteria.internal.compile.RenderingContext;

Models a path for a SingularAttribute generally obtained from a Path.get(SingularAttribute) call
Author:Steve Ebersole
/** * Models a path for a {@link SingularAttribute} generally obtained from a * {@link javax.persistence.criteria.Path#get(SingularAttribute)} call * * @author Steve Ebersole */
public class SingularAttributePath<X> extends AbstractPathImpl<X> implements Serializable { private final SingularAttribute<?,X> attribute; private final ManagedType<X> managedType; @SuppressWarnings({ "unchecked" }) public SingularAttributePath( CriteriaBuilderImpl criteriaBuilder, Class<X> javaType, PathSource pathSource, SingularAttribute<?, X> attribute) { super( criteriaBuilder, javaType, pathSource ); this.attribute = attribute; this.managedType = resolveManagedType( attribute ); } private ManagedType<X> resolveManagedType(SingularAttribute<?, X> attribute) { if ( Attribute.PersistentAttributeType.BASIC == attribute.getPersistentAttributeType() ) { return null; } else if ( Attribute.PersistentAttributeType.EMBEDDED == attribute.getPersistentAttributeType() ) { return (EmbeddableType<X>) attribute.getType(); } else { return (IdentifiableType<X>) attribute.getType(); } } @Override public SingularAttribute<?, X> getAttribute() { return attribute; } @Override public Bindable<X> getModel() { return getAttribute(); } @Override protected boolean canBeDereferenced() { return managedType != null; } @Override protected Attribute locateAttributeInternal(String attributeName) { final Attribute attribute = managedType.getAttribute( attributeName ); // ManagedType.locateAttribute should throw exception rather than return // null, but just to be safe... if ( attribute == null ) { throw new IllegalArgumentException( "Could not resolve attribute named " + attributeName ); } return attribute; } @Override public <T extends X> SingularAttributePath<T> treatAs(Class<T> treatAsType) { return new TreatedSingularAttributePath<T>( this, treatAsType ); } public static class TreatedSingularAttributePath<T> extends SingularAttributePath<T> { private final SingularAttributePath<? super T> original; private final Class<T> treatAsType; @SuppressWarnings("unchecked") public TreatedSingularAttributePath(SingularAttributePath<? super T> original, Class<T> treatAsType) { super( original.criteriaBuilder(), treatAsType, original.getPathSource(), (SingularAttribute<?, T>) original.getAttribute() ); this.original = original; this.treatAsType = treatAsType; } @Override public String getAlias() { return original.getAlias(); } @Override public void prepareAlias(RenderingContext renderingContext) { // do nothing... } @Override public String render(RenderingContext renderingContext) { return "treat(" + original.render( renderingContext ) + " as " + treatAsType.getName() + ")"; } } }