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/*******************************************************************************
* Copyright (c) 2011, 2014 Oracle and/or its affiliates. All rights reserved.
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
* which accompanies this distribution.
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
* and the Eclipse Distribution License is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* Contributors:
* Oracle - initial API and implementation
*
******************************************************************************/
package org.eclipse.persistence.jpa.jpql.tools.model.query;
import org.eclipse.persistence.jpa.jpql.parser.InternalEntityTypeExpressionBNF;
import org.eclipse.persistence.jpa.jpql.parser.TypeExpression;
import static org.eclipse.persistence.jpa.jpql.parser.Expression.*;
/**
* An entity type expression can be used to restrict query polymorphism. The TYPE
* operator returns the exact type of the argument.
*
* Part of JPA 2.0.
*
*
BNF: type_discriminator ::= TYPE(identification_variable |
* single_valued_object_path_expression |
* input_parameter)
*
* @see TypeExpression
*
* @version 2.4
* @since 2.4
* @author Pascal Filion
*/
public class TypeExpressionStateObject extends AbstractSingleEncapsulatedExpressionStateObject {
/**
* Creates a new TypeExpressionStateObject
.
*
* @param parent The parent of this state object, which cannot be null
* @exception NullPointerException The given parent cannot be null
*/
public TypeExpressionStateObject(StateObject parent) {
super(parent);
}
/**
* Creates a new TypeExpressionStateObject
.
*
* @param parent The parent of this state object, which cannot be null
* @param stateObject The {@link StateObject} representing the encapsulated expression
* @exception NullPointerException The given parent cannot be null
*/
public TypeExpressionStateObject(StateObject parent, StateObject stateObject) {
super(parent, stateObject);
}
/**
* Creates a new TypeExpressionStateObject
.
*
* @param parent The parent of this state object, which cannot be null
* @param path Either the identification variable, the singled-valued object path expression or
* the input parameter
* @exception NullPointerException The given parent cannot be null
*/
public TypeExpressionStateObject(StateObject parent, String path) {
super(parent, path);
}
/**
* {@inheritDoc}
*/
public void accept(StateObjectVisitor visitor) {
visitor.visit(this);
}
/**
* {@inheritDoc}
*/
@Override
public TypeExpression getExpression() {
return (TypeExpression) super.getExpression();
}
/**
* {@inheritDoc}
*/
@Override
public String getIdentifier() {
return TYPE;
}
/**
* {@inheritDoc}
*/
@Override
protected String getQueryBNFId() {
return InternalEntityTypeExpressionBNF.ID;
}
/**
* Keeps a reference of the {@link TypeExpression parsed object} object, which should only be
* done when this object is instantiated during the conversion of a parsed JPQL query into
* {@link StateObject StateObjects}.
*
* @param expression The {@link TypeExpression parsed object} representing a TYPE
* expression
*/
public void setExpression(TypeExpression expression) {
super.setExpression(expression);
}
/**
* {@inheritDoc}
*/
@Override
public void setStateObject(StateObject stateObject) {
super.setStateObject(stateObject);
}
}