| /* |
| * 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.ResultVariable; |
| import org.eclipse.persistence.jpa.jpql.parser.SelectExpressionBNF; |
| import static org.eclipse.persistence.jpa.jpql.parser.AbstractExpression.*; |
| |
| /** |
| * A result variable may be used to name a select item in the query result. |
| * |
| * <div><p><b>BNF:</b> <code>select_item ::= select_expression [[AS] result_variable]</code></p></div> |
| * |
| * @see ResultVariable |
| * |
| * @version 2.4 |
| * @since 2.4 |
| * @author Pascal Filion |
| */ |
| @SuppressWarnings({"nls", "unused"}) // unused used for the import statement: see bug 330740 |
| public class ResultVariableStateObject extends AbstractStateObject { |
| |
| /** |
| * Flag used to determine if the <code><b>AS</b></code> identifier is used or not. |
| */ |
| private boolean as; |
| |
| /** |
| * The result variable identifies the select expression, which can be used in the |
| * <code><b>ORDER BY</b></code> clause. |
| */ |
| private IdentificationVariableStateObject resultVariable; |
| |
| /** |
| * The state object representing the select expression that is named with a result variable. |
| */ |
| private StateObject stateObject; |
| |
| /** |
| * Notifies the visibility of the <code><b>AS</b></code> identifier has changed. |
| */ |
| public static final String AS_PROPERTY = "as"; |
| |
| /** |
| * Notifies the result variable property has changed. |
| */ |
| public static final String RESULT_VARIABLE_PROPERTY = "resultVariable"; |
| |
| /** |
| * Notifies the select state object property has changed. |
| */ |
| public static final String STATE_OBJECT_PROPERTY = "selectStateObject"; |
| |
| /** |
| * Creates a new <code>ResultVariableStateObject</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 ResultVariableStateObject(SelectClauseStateObject parent) { |
| super(parent); |
| } |
| |
| /** |
| * Creates a new <code>ResultVariableStateObject</code>. |
| * |
| * @param parent The parent of this state object, which cannot be <code>null</code> |
| * @param stateObject The {@link StateObject} representing the select item |
| * @param as Determines whether the <code><b>AS</b></code> identifier is used or not |
| * @param resultVariable The variable identifying the select item |
| * @exception NullPointerException The given parent cannot be <code>null</code> |
| */ |
| public ResultVariableStateObject(SelectClauseStateObject parent, |
| StateObject stateObject, |
| boolean as, |
| String resultVariable) { |
| |
| super(parent); |
| this.as = as; |
| this.stateObject = parent(stateObject); |
| this.resultVariable.setTextInternally(resultVariable); |
| } |
| |
| /** |
| * Creates a new <code>ResultVariableStateObject</code>. |
| * |
| * @param parent The parent of this state object, which cannot be <code>null</code> |
| * @param stateObject The {@link StateObject} representing the select item |
| * @param resultVariable The variable identifying the select item |
| * @exception NullPointerException The given parent cannot be <code>null</code> |
| */ |
| public ResultVariableStateObject(SelectClauseStateObject parent, |
| StateObject stateObject, |
| String resultVariable) { |
| |
| this(parent, stateObject, false, resultVariable); |
| } |
| |
| @Override |
| public void accept(StateObjectVisitor visitor) { |
| visitor.visit(this); |
| } |
| |
| /** |
| * Makes sure the <code><b>AS</b></code> identifier is used. |
| * |
| * @return This object |
| */ |
| public ResultVariableStateObject addAs() { |
| if (!as) { |
| setAs(true); |
| } |
| return this; |
| } |
| |
| @Override |
| protected void addChildren(List<StateObject> children) { |
| super.addChildren(children); |
| if (stateObject != null) { |
| children.add(stateObject); |
| } |
| children.add(resultVariable); |
| } |
| |
| @Override |
| public ResultVariable getExpression() { |
| return (ResultVariable) super.getExpression(); |
| } |
| |
| @Override |
| public SelectClauseStateObject getParent() { |
| return (SelectClauseStateObject) super.getParent(); |
| } |
| |
| /** |
| * Returns the result variable identifies the select expression, which can be used in the |
| * <code><b>ORDER BY</b></code> clause. |
| * |
| * @return The unique identifier declaring the select expression |
| */ |
| public String getResultVariable() { |
| return resultVariable.getText(); |
| } |
| |
| /** |
| * Returns the {@link StateObject} representing a single select expression. |
| * |
| * @return The {@link StateObject} representing a single select expression |
| */ |
| public StateObject getStateObject() { |
| return stateObject; |
| } |
| |
| /** |
| * Determines whether the <code><b>AS</b></code> identifier is used. |
| * |
| * @return <code>true</code> if the <code><b>AS</b></code> identifier is used; <code>false</code> |
| * otherwise |
| */ |
| public boolean hasAs() { |
| return as; |
| } |
| |
| /** |
| * Determines whether the result variable has been defined. |
| * |
| * @return <code>true</code> if the result variable is defined; <code>false</code> otherwise |
| */ |
| public boolean hasResultVariable() { |
| return resultVariable.hasText(); |
| } |
| |
| /** |
| * Determines whether the select item has been defined. |
| * |
| * @return <code>true</code> if there the selected expression has been defined; <code>false</code> |
| * if it's missing |
| */ |
| public boolean hasStateObject() { |
| return stateObject != null; |
| } |
| |
| @Override |
| protected void initialize() { |
| super.initialize(); |
| resultVariable = new IdentificationVariableStateObject(this); |
| } |
| |
| @Override |
| public boolean isEquivalent(StateObject stateObject) { |
| |
| if (super.isEquivalent(stateObject)) { |
| ResultVariableStateObject resultVariable = (ResultVariableStateObject) stateObject; |
| return as == resultVariable.as && |
| resultVariable.isEquivalent(resultVariable.resultVariable) && |
| areEquivalent(stateObject, resultVariable.stateObject); |
| } |
| |
| return false; |
| } |
| |
| /** |
| * Parses the given JPQL fragment, which represents a single select expression, and creates the |
| * {@link StateObject}. |
| * |
| * @param jpqlFragment The portion of the query representing a single select expression |
| */ |
| public void parse(String jpqlFragment) { |
| StateObject stateObject = buildStateObject(jpqlFragment, SelectExpressionBNF.ID); |
| setStateObject(stateObject); |
| } |
| |
| /** |
| * Makes sure the <code><b>AS</b></code> identifier is not used. |
| */ |
| public void removeAs() { |
| if (as) { |
| setAs(true); |
| } |
| } |
| |
| /** |
| * Sets whether the <code><b>AS</b></code> identifier should be used. |
| * |
| * @param as <code>true</code> if the <code><b>AS</b></code> identifier should be used part; |
| * <code>false</code> otherwise |
| */ |
| public void setAs(boolean as) { |
| boolean oldAs = this.as; |
| this.as = as; |
| firePropertyChanged(AS_PROPERTY, oldAs, as); |
| } |
| |
| /** |
| * Keeps a reference of the {@link ResultVariable 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 ResultVariable parsed object} representing a result variable |
| * expression |
| */ |
| public void setExpression(ResultVariable expression) { |
| super.setExpression(expression); |
| } |
| |
| /** |
| * Sets the result variable that identifies the select expression, which can be used in the |
| * <code><b>ORDER BY</b></code> clause. |
| * |
| * @param resultVariable The unique identifier declaring the select expression |
| */ |
| public void setResultVariable(String resultVariable) { |
| String oldResultVariable = getResultVariable(); |
| this.resultVariable.setText(resultVariable); |
| firePropertyChanged(RESULT_VARIABLE_PROPERTY, oldResultVariable, resultVariable); |
| } |
| |
| /** |
| * Sets the {@link StateObject} representing a single select expression. |
| * |
| * @param stateObject The {@link StateObject} representing a single select expression |
| */ |
| public void setStateObject(StateObject stateObject) { |
| StateObject oldStateObject = this.stateObject; |
| this.stateObject = parent(stateObject); |
| firePropertyChanged(STATE_OBJECT_PROPERTY, oldStateObject, stateObject); |
| } |
| |
| /** |
| * Toggles the visibility of the <code><b>AS</b></code> identifier; either adds it if it's not |
| * present otherwise removes it if it's present. |
| */ |
| public void toggleAs() { |
| setAs(!as); |
| } |
| |
| @Override |
| protected void toTextInternal(Appendable writer) throws IOException { |
| |
| if (stateObject != null) { |
| stateObject.toString(writer); |
| writer.append(SPACE); |
| } |
| |
| if (as) { |
| writer.append(AS); |
| } |
| |
| if (hasResultVariable()) { |
| writer.append(SPACE); |
| resultVariable.toTextInternal(writer); |
| } |
| } |
| } |