| /* |
| * 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. |
| * <p> |
| * The unique identifier for this BNF is automatically generated and can be retrieved with |
| * {@link VirtualJPQLQueryBNF#getId()}. |
| * <p> |
| * 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 <code>VirtualJPQLQueryBNF</code>. |
| * |
| * @param jpqlGrammar The {@link JPQLGrammar} to integrate this virtual query BNF |
| * @exception NullPointerException If the given {@link JPQLGrammar} is <code>null</code> |
| */ |
| 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 <code>queryBNFId</code> cannot be <code>null</code> |
| */ |
| public void registerQueryBNF(String queryBNFId) { |
| registerChild(queryBNFId); |
| } |
| } |