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/*
* Copyright (c) 2011, 2020 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 v. 2.0 which is available at
* http://www.eclipse.org/legal/epl-2.0,
* or the Eclipse Distribution License v. 1.0 which is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
*/
// Contributors:
// Oracle - initial API and implementation
//
package org.eclipse.persistence.jpa.jpql.parser;
import java.util.Random;
/**
* This {@link JPQLQueryBNF} can be used as a virtual BNF, which can wrap another BNF or BNFs and
* modify the default behavior.
*
* The unique identifier for this BNF is automatically generated and can be retrieved with
* {@link VirtualJPQLQueryBNF#getId()}.
*
* Once this BNF is no longer needed, {@link #dispose()} needs to be called.
*
* @version 2.4
* @since 2.4
* @author Pascal Filion
*/
public final class VirtualJPQLQueryBNF extends JPQLQueryBNF {
private static final Random r = new Random(System.currentTimeMillis());
/**
* Creates a new VirtualJPQLQueryBNF.
*
* @param jpqlGrammar The {@link JPQLGrammar} to integrate this virtual query BNF
* @exception NullPointerException If the given {@link JPQLGrammar} is null
*/
public VirtualJPQLQueryBNF(JPQLGrammar jpqlGrammar) {
super(String.valueOf(r.nextLong()));
initialize(jpqlGrammar);
}
/**
* Disposes this "virtual" query BNF.
*/
public void dispose() {
getExpressionRegistry().unregisterBNF(this);
}
private void initialize(JPQLGrammar jpqlGrammar) {
ExpressionRegistry expressionRegistry = jpqlGrammar.getExpressionRegistry();
setExpressionRegistry(expressionRegistry);
expressionRegistry.registerBNF(this);
}
/**
* Registers a unique identifier that will be used to create the {@link Expression} representing
* this BNF rule.
*
* @param expressionFactoryId The unique identifier that is responsible to create the
* {@link Expression} for this BNF rule
*/
public void registerFactory(String expressionFactoryId) {
registerExpressionFactory(expressionFactoryId);
}
/**
* Registers the unique identifier of the BNF rule as a child of this BNF rule.
*
* @param queryBNFId The unique identifier of the BNF rule
* @exception NullPointerException The queryBNFId cannot be null
*/
public void registerQueryBNF(String queryBNFId) {
registerChild(queryBNFId);
}
}