| /* |
| * Copyright (c) 2011, 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.tools.model.query; |
| |
| import java.io.IOException; |
| import java.util.List; |
| import org.eclipse.persistence.jpa.jpql.parser.SimpleSelectClause; |
| import org.eclipse.persistence.jpa.jpql.parser.SimpleSelectExpressionBNF; |
| import org.eclipse.persistence.jpa.jpql.tools.model.ISimpleSelectExpressionStateObjectBuilder; |
| import static org.eclipse.persistence.jpa.jpql.parser.AbstractExpression.*; |
| |
| /** |
| * The <b>SELECT</b> statement queries data from entities. This version simply does not handle |
| * <b>OBJECT</b> and <b>NEW</b> identifiers. It is used from within another expression. |
| * |
| * <div><p><b>BNF:</b> <code>simple_select_clause ::= SELECT [DISTINCT] simple_select_expression</code></p></div> |
| * |
| * @see SimpleSelectClause |
| * |
| * @version 2.4 |
| * @since 2.4 |
| * @author Pascal Filion |
| */ |
| @SuppressWarnings({"nls", "unused"}) // unused used for the import statement: see bug 330740 |
| public class SimpleSelectClauseStateObject extends AbstractSelectClauseStateObject { |
| |
| /** |
| * The builder is cached during the creation of the select expression. |
| */ |
| private ISimpleSelectExpressionStateObjectBuilder builder; |
| |
| /** |
| * The state object representing the single select expression. |
| */ |
| private StateObject stateObject; |
| |
| /** |
| * Notifies the select expression property has changed. |
| */ |
| public static final String SELECT_ITEM_PROPERTY = "stateObject"; |
| |
| /** |
| * Creates a new <code>SubQuerySelectClauseStateObject</code>. |
| * |
| * @param parent The parent of this state object, which cannot be <code>null</code> |
| * @exception NullPointerException The given parent cannot be <code>null</code> |
| */ |
| public SimpleSelectClauseStateObject(SimpleSelectStatementStateObject parent) { |
| super(parent); |
| } |
| |
| @Override |
| public void accept(StateObjectVisitor visitor) { |
| visitor.visit(this); |
| } |
| |
| @Override |
| protected void addChildren(List<StateObject> children) { |
| super.addChildren(children); |
| if (stateObject != null) { |
| children.add(stateObject); |
| } |
| } |
| |
| /** |
| * Creates and returns a new {@link ISimpleSelectExpressionStateObjectBuilder} that can be used |
| * to programmatically create a single select expression and once the expression is complete, |
| * {@link ISimpleSelectExpressionStateObjectBuilder#commit()} will push the {@link StateObject} |
| * representation of that expression as this clause's select expression. |
| * |
| * @return A new builder that can be used to quickly create a select expression |
| */ |
| public ISimpleSelectExpressionStateObjectBuilder getBuilder() { |
| if (builder == null) { |
| builder = getQueryBuilder().buildStateObjectBuilder(this); |
| } |
| return builder; |
| } |
| |
| @Override |
| public SimpleSelectClause getExpression() { |
| return (SimpleSelectClause) super.getExpression(); |
| } |
| |
| @Override |
| public SimpleFromClauseStateObject getFromClause() { |
| return (SimpleFromClauseStateObject) super.getFromClause(); |
| } |
| |
| @Override |
| public SimpleSelectStatementStateObject getParent() { |
| return (SimpleSelectStatementStateObject) super.getParent(); |
| } |
| |
| /** |
| * Returns |
| * |
| */ |
| public StateObject getSelectItem() { |
| return stateObject; |
| } |
| |
| @Override |
| public boolean hasSelectItem() { |
| return stateObject != null; |
| } |
| |
| @Override |
| public boolean isEquivalent(StateObject stateObject) { |
| |
| if (super.isEquivalent(stateObject)) { |
| SimpleSelectClauseStateObject select = (SimpleSelectClauseStateObject) stateObject; |
| return areEquivalent(this.stateObject, select.stateObject); |
| } |
| |
| return false; |
| } |
| |
| @Override |
| public void parse(String jpqlFragment) { |
| StateObject stateObject = buildStateObject(jpqlFragment, SimpleSelectExpressionBNF.ID); |
| setSelectItem(stateObject); |
| } |
| |
| /** |
| * Keeps a reference of the {@link SimpleSelectClause 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 SimpleSelectClause parsed object} representing a subquery |
| * <code><b>SELECT</b></code> clause |
| */ |
| public void setExpression(SimpleSelectClause expression) { |
| super.setExpression(expression); |
| } |
| |
| /** |
| * Sets the given {@link StateObject} as this clause's select item. |
| * |
| * @param stateObject The {@link StateObject} representing the single select item |
| */ |
| public void setSelectItem(StateObject stateObject) { |
| StateObject oldStateObject = this.stateObject; |
| this.stateObject = parent(stateObject); |
| firePropertyChanged(SELECT_ITEM_PROPERTY, oldStateObject, stateObject); |
| } |
| |
| @Override |
| protected void toTextInternal(Appendable writer) throws IOException { |
| |
| // 'SELECT' |
| writer.append(SELECT); |
| |
| // 'DISTINCT' |
| if (hasDistinct()) { |
| writer.append(SPACE); |
| writer.append(DISTINCT); |
| } |
| |
| // Select expression |
| if (stateObject != null) { |
| writer.append(SPACE); |
| stateObject.toString(writer); |
| } |
| } |
| } |