| /* |
| * 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.ArrayList; |
| import java.util.Collection; |
| import java.util.List; |
| import org.eclipse.persistence.jpa.jpql.WordParser; |
| |
| /** |
| * The <b>GROUP BY</b> construct enables the aggregation of values according to the properties of an |
| * entity class. |
| * |
| * <div><b>BNF:</b> <code>groupby_clause ::= GROUP BY groupby_item {, groupby_item}*</code></div> |
| * |
| * @version 2.5.1 |
| * @since 2.3 |
| * @author Pascal Filion |
| */ |
| public final class GroupByClause extends AbstractExpression { |
| |
| /** |
| * The unique group by item or the collection of group by items. |
| */ |
| private AbstractExpression groupByItems; |
| |
| /** |
| * Determines whether a whitespace was parsed after <b>GROUP BY</b>. |
| */ |
| private boolean hasSpace; |
| |
| /** |
| * The actual <b>GROUP BY</b> identifier found in the string representation of the JPQL query. |
| */ |
| private String identifier; |
| |
| /** |
| * Creates a new <code>GroupByClause</code>. |
| * |
| * @param parent The parent of this expression |
| */ |
| public GroupByClause(AbstractExpression parent) { |
| super(parent, GROUP_BY); |
| } |
| |
| @Override |
| public void accept(ExpressionVisitor visitor) { |
| visitor.visit(this); |
| } |
| |
| @Override |
| public void acceptChildren(ExpressionVisitor visitor) { |
| getGroupByItems().accept(visitor); |
| } |
| |
| @Override |
| protected void addChildrenTo(Collection<Expression> children) { |
| children.add(getGroupByItems()); |
| } |
| |
| @Override |
| protected void addOrderedChildrenTo(List<Expression> children) { |
| |
| children.add(buildStringExpression(getText())); |
| |
| if (hasSpace) { |
| children.add(buildStringExpression(SPACE)); |
| } |
| |
| if (groupByItems != null) { |
| children.add(groupByItems); |
| } |
| } |
| |
| /** |
| * Creates a new {@link CollectionExpression} that will wrap the single group by item. |
| * |
| * @return The single group by item represented by a temporary collection |
| */ |
| public CollectionExpression buildCollectionExpression() { |
| |
| List<AbstractExpression> children = new ArrayList<>(1); |
| children.add((AbstractExpression) getGroupByItems()); |
| |
| List<Boolean> commas = new ArrayList<>(1); |
| commas.add(Boolean.FALSE); |
| |
| List<Boolean> spaces = new ArrayList<>(1); |
| spaces.add(Boolean.FALSE); |
| |
| return new CollectionExpression(this, children, commas, spaces, true); |
| } |
| |
| @Override |
| public JPQLQueryBNF findQueryBNF(Expression expression) { |
| |
| if ((groupByItems != null) && groupByItems.isAncestor(expression)) { |
| return getQueryBNF(GroupByItemBNF.ID); |
| } |
| |
| return super.findQueryBNF(expression); |
| } |
| |
| /** |
| * Returns the actual <b>GROUP BY</b> found in the string representation of the JPQL query, which |
| * has the actual case that was used. |
| * |
| * @return The <b>GROUP BY</b> identifier that was actually parsed |
| */ |
| public String getActualIdentifier() { |
| return identifier; |
| } |
| |
| /** |
| * Returns the {@link Expression} that represents the list of group by items if any was parsed. |
| * |
| * @return The expression that was parsed representing the list of items |
| */ |
| public Expression getGroupByItems() { |
| if (groupByItems == null) { |
| groupByItems = buildNullExpression(); |
| } |
| return groupByItems; |
| } |
| |
| @Override |
| public JPQLQueryBNF getQueryBNF() { |
| return getQueryBNF(GroupByClauseBNF.ID); |
| } |
| |
| /** |
| * Determines whether the list of items was parsed. |
| * |
| * @return <code>true</code> if at least one item was parsed; <code>false</code> otherwise |
| */ |
| public boolean hasGroupByItems() { |
| return groupByItems != null && |
| !groupByItems.isNull(); |
| } |
| |
| /** |
| * Determines whether a whitespace was found after <b>GROUP BY</b>. |
| * |
| * @return <code>true</code> if there was a whitespace after <b>GROUP BY</b>; <code>false</code> otherwise |
| */ |
| public boolean hasSpaceAfterGroupBy() { |
| return hasSpace; |
| } |
| |
| @Override |
| protected void parse(WordParser wordParser, boolean tolerant) { |
| |
| // Parse 'GROUP BY' |
| identifier = wordParser.moveForwardIgnoreWhitespace(GROUP_BY); |
| |
| hasSpace = wordParser.skipLeadingWhitespace() > 0; |
| |
| // Group by items |
| groupByItems = parse(wordParser, GroupByItemBNF.ID, tolerant); |
| } |
| |
| @Override |
| protected void toParsedText(StringBuilder writer, boolean actual) { |
| |
| // 'GROUP BY' |
| writer.append(actual ? identifier : getText()); |
| |
| if (hasSpace) { |
| writer.append(SPACE); |
| } |
| |
| // Group by items |
| if (groupByItems != null) { |
| groupByItems.toParsedText(writer, actual); |
| } |
| } |
| } |