| /* |
| * Copyright (c) 2006, 2021 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.Arrays; |
| import org.eclipse.persistence.jpa.jpql.WordParser; |
| |
| /** |
| * An <code>ExpressionFactory</code> is responsible to parse a portion of JPQL query which starts |
| * with one of the factory's JPQL identifiers. |
| * <p> |
| * Provisional API: This interface is part of an interim API that is still under development and |
| * expected to change significantly before reaching stability. It is available at this early stage |
| * to solicit feedback from pioneering adopters on the understanding that any code that uses this |
| * API will almost certainly be broken (repeatedly) as the API evolves. |
| * |
| * @version 2.5 |
| * @since 2.3 |
| * @author Pascal Filion |
| */ |
| @SuppressWarnings("nls") |
| public abstract class ExpressionFactory implements Comparable<ExpressionFactory> { |
| |
| /** |
| * The {@link ExpressionRegistry} with which this {@link ExpressionFactory} was registered. |
| */ |
| private ExpressionRegistry expressionRegistry; |
| |
| /** |
| * The unique identifier of this {@link ExpressionFactory}. |
| */ |
| private final String id; |
| |
| /** |
| * The JPQL identifiers handled by this factory. |
| */ |
| private String[] identifiers; |
| |
| /** |
| * Creates a new <code>ExpressionFactory</code>. |
| * |
| * @param id The unique identifier of this <code>ExpressionFactory</code> |
| * @param identifiers The JPQL identifiers handled by this factory |
| * @exception NullPointerException The given unique identifier cannot be <code>null</code> or |
| * the list of JPQL identifiers was <code>null</code> |
| */ |
| protected ExpressionFactory(String id, String... identifiers) { |
| super(); |
| this.id = id; |
| this.identifiers = identifiers; |
| } |
| |
| /** |
| * Adds the given JPQL identifier to this factory. |
| * |
| * @param identifier The JPQL identifier this factory will parse |
| */ |
| void addIdentifier(String identifier) { |
| |
| String[] newIdentifiers = new String[identifiers.length + 1]; |
| newIdentifiers[identifiers.length] = identifier; |
| System.arraycopy(identifiers, 0, newIdentifiers, 0, identifiers.length); |
| |
| identifiers = newIdentifiers; |
| } |
| |
| /** |
| * Adds the given JPQL identifiers to this factory. |
| * |
| * @param identifiers The JPQL identifiers this factory will parse |
| */ |
| void addIdentifiers(String... identifiers) { |
| |
| int originalLength = this.identifiers.length; |
| |
| String[] newIdentifiers = new String[this.identifiers.length + identifiers.length]; |
| System.arraycopy(this.identifiers, 0, newIdentifiers, 0, this.identifiers.length); |
| System.arraycopy(identifiers, 0, newIdentifiers, originalLength, identifiers.length); |
| |
| this.identifiers = newIdentifiers; |
| } |
| |
| /** |
| * Creates a new {@link Expression}. |
| * |
| * @param parent The parent {@link AbstractExpression} |
| * @param wordParser The text to parse based on the current position of the cursor |
| * @param word The current word being parsed |
| * @param queryBNF The BNF grammar that was used to identifier this factory to be capable to |
| * parse a portion of the query |
| * @param expression During the parsing, it is possible the first part of an expression was |
| * parsed which needs to be used as a sub-expression of the newly created expression |
| * @return A new {@link AbstractExpression} representing the portion or the totality of the |
| * text held by {@link WordParser} starting at the cursor position |
| */ |
| protected abstract AbstractExpression buildExpression(AbstractExpression parent, |
| WordParser wordParser, |
| String word, |
| JPQLQueryBNF queryBNF, |
| AbstractExpression expression, |
| boolean tolerant); |
| |
| @Override |
| public final int compareTo(ExpressionFactory expressionFactory) { |
| return id.compareTo(expressionFactory.getId()); |
| } |
| |
| @Override |
| public final boolean equals(Object object) { |
| if (object == null) { |
| return false; |
| } |
| if (this == object) { |
| return true; |
| } |
| |
| ExpressionFactory factory = (ExpressionFactory) object; |
| return id.equals(factory.id); |
| } |
| |
| /** |
| * Returns the registry containing the {@link JPQLQueryBNF JPQLQueryBNFs} and the {@link |
| * org.eclipse.persistence.jpa.jpql.parser.ExpressionFactory ExpressionFactories} that are used |
| * to properly parse a JPQL query. |
| * |
| * @return The registry containing the information related to the JPQL grammar |
| */ |
| public final ExpressionRegistry getExpressionRegistry() { |
| return expressionRegistry; |
| } |
| |
| /** |
| * Returns the unique identifier of this <code>ExpressionFactory</code>. |
| * |
| * @return The identifier used to register this {@link ExpressionFactory} with {@link |
| * ExpressionRegistry} |
| */ |
| public final String getId() { |
| return id; |
| } |
| |
| @Override |
| public final int hashCode() { |
| return id.hashCode(); |
| } |
| |
| /** |
| * Returns the JPQL identifiers handled by this factory. |
| * |
| * @return The list of JPQL identifiers this factory knows how to parse |
| */ |
| public final String[] identifiers() { |
| return identifiers; |
| } |
| |
| /** |
| * Sets the backpointer to the {@link ExpressionRegistry} with which this {@link JPQLQueryBNF} |
| * was registered. |
| * |
| * @param expressionRegistry The registry for a given JPQL grammar |
| */ |
| final void setExpressionRegistry(ExpressionRegistry expressionRegistry) { |
| this.expressionRegistry = expressionRegistry; |
| } |
| |
| @Override |
| public final String toString() { |
| StringBuilder sb = new StringBuilder(); |
| sb.append(getClass().getSimpleName()); |
| sb.append("(id="); |
| sb.append(id); |
| sb.append(", identifiers="); |
| sb.append(Arrays.toString(identifiers)); |
| sb.append(")"); |
| return sb.toString(); |
| } |
| } |