| /* |
| * 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.tools.model.query; |
| |
| import java.io.IOException; |
| import java.util.List; |
| import java.util.ListIterator; |
| import org.eclipse.persistence.jpa.jpql.Assert; |
| import org.eclipse.persistence.jpa.jpql.parser.Join; |
| import org.eclipse.persistence.jpa.jpql.utility.iterable.ListIterable; |
| import static org.eclipse.persistence.jpa.jpql.parser.AbstractExpression.*; |
| |
| /** |
| * A <code><b>JOIN</b></code> enables the fetching of an association as a side effect of the |
| * execution of a query. A <code><b>JOIN</b></code> is specified over an entity and its related |
| * entities. |
| * |
| * <div><p><b>BNF:</b> <code>join ::= join_spec join_association_path_expression [AS] identification_variable</code></p></div> |
| * <p> |
| * A <b>JOIN FETCH</b> enables the fetching of an association as a side effect of the execution of |
| * a query. A <b>JOIN FETCH</b> is specified over an entity and its related entities. |
| * |
| * <div><p><b>BNF:</b> <code>fetch_join ::= join_spec FETCH join_association_path_expression</code></p></div> |
| * |
| * @see Join |
| * |
| * @version 2.4 |
| * @since 2.4 |
| * @author Pascal Filion |
| */ |
| @SuppressWarnings({"nls", "unused"}) // unused used for the import statement: see bug 330740 |
| public class JoinStateObject extends AbstractStateObject { |
| |
| /** |
| * Flag used to determine if the <code><b>AS</b></code> identifier is used or not. |
| */ |
| private boolean as; |
| |
| /** |
| * The state object holding the identification variable. |
| */ |
| private IdentificationVariableStateObject identificationVariable; |
| |
| /** |
| * The state object holding the join association path. |
| */ |
| private CollectionValuedPathExpressionStateObject joinAssociationPath; |
| |
| /** |
| * One of the joining types used by this state object. |
| */ |
| private String joinType; |
| |
| /** |
| * Notifies the visibility of the <code><b>AS</b></code> identifier has changed. |
| */ |
| public static final String AS_PROPERTY = "as"; |
| |
| /** |
| * Notifies the join type property has changed. |
| */ |
| public static final String JOIN_TYPE_PROPERTY = "joinType"; |
| |
| /** |
| * Creates a new <code>JoinStateObject</code>. |
| * |
| * @param parent The parent of this state object |
| * @param joinType One of the joining types |
| */ |
| public JoinStateObject(AbstractIdentificationVariableDeclarationStateObject parent, |
| String joinType) { |
| |
| this(parent, joinType, false); |
| } |
| |
| /** |
| * Creates a new <code>JoinStateObject</code>. |
| * |
| * @param parent The parent of this state object |
| * @param joinType One of the joining types |
| * @param as Determine whether the <code><b>AS</b></code> identifier is used or not |
| */ |
| public JoinStateObject(AbstractIdentificationVariableDeclarationStateObject parent, |
| String joinType, |
| boolean as) { |
| |
| super(parent); |
| validateJoinType(joinType); |
| this.joinType = joinType; |
| this.as = as; |
| } |
| |
| @Override |
| public void accept(StateObjectVisitor visitor) { |
| visitor.visit(this); |
| } |
| |
| /** |
| * Makes sure the <code><b>AS</b></code> identifier is specified. |
| * |
| * @return This object |
| */ |
| public JoinStateObject addAs() { |
| if (!as) { |
| setAs(true); |
| } |
| return this; |
| } |
| |
| @Override |
| protected void addChildren(List<StateObject> children) { |
| super.addChildren(children); |
| children.add(joinAssociationPath); |
| children.add(identificationVariable); |
| } |
| |
| /** |
| * Adds the given segments to the end of the join association path expression. The identification |
| * variable will not be affected. |
| * |
| * @param paths The new path expression |
| */ |
| public void addJoinAssociationPaths(List<String> paths) { |
| joinAssociationPath.addItems(paths); |
| } |
| |
| @Override |
| public Join getExpression() { |
| return (Join) super.getExpression(); |
| } |
| |
| /** |
| * Returns the name of the identification variable that defines the join association path. |
| * |
| * @return The variable defining the join association path |
| */ |
| public String getIdentificationVariable() { |
| return identificationVariable.getText(); |
| } |
| |
| /** |
| * Returns the state object holding the identification variable. |
| * |
| * @return The portion of the joining expression representing the identification variable |
| */ |
| public IdentificationVariableStateObject getIdentificationVariableStateObject() { |
| return identificationVariable; |
| } |
| |
| /** |
| * Returns the {@link StateObject} representing the identification variable that starts the path |
| * expression, which can be a sample identification variable, a map value, map key or map entry |
| * expression. |
| * |
| * @return The root of the path expression |
| */ |
| public StateObject getJoinAssociationIdentificationVariable() { |
| return joinAssociationPath.getIdentificationVariable(); |
| } |
| |
| /** |
| * Returns the {@link CollectionValuedPathExpressionStateObject} representing the join |
| * association path. |
| * |
| * @return The state object representing the join association path |
| */ |
| public CollectionValuedPathExpressionStateObject getJoinAssociationPathStateObject() { |
| return joinAssociationPath; |
| } |
| |
| /** |
| * Returns the joining type. |
| * |
| * @return The joining type of this joining expression |
| */ |
| public String getJoinType() { |
| return joinType; |
| } |
| |
| @Override |
| public AbstractIdentificationVariableDeclarationStateObject getParent() { |
| return (AbstractIdentificationVariableDeclarationStateObject) super.getParent(); |
| } |
| |
| /** |
| * Determines whether the <code><b>AS</b></code> identifier is used or not. |
| * |
| * @return <code>true</code> if the <code><b>AS</b></code> identifier is part of the expression; |
| * <code>false</code> otherwise |
| */ |
| public boolean hasAs() { |
| return as; |
| } |
| |
| /** |
| * Determines whether the identifier <b>FETCH</b> was parsed. |
| * |
| * @return <code>true</code> if the identifier <b>FETCH</b> was parsed; <code>false</code> otherwise |
| */ |
| public boolean hasFetch() { |
| String joinType = getJoinType(); |
| return joinType == JOIN_FETCH || |
| joinType == INNER_JOIN_FETCH || |
| joinType == LEFT_JOIN_FETCH || |
| joinType == LEFT_OUTER_JOIN_FETCH; |
| } |
| |
| /** |
| * Determines whether the identification variable has been defined. |
| * |
| * @return <code>true</code> if the identification has been defined; <code>false</code> otherwise |
| */ |
| public boolean hasIdentificationVariable() { |
| return identificationVariable.hasText(); |
| } |
| |
| @Override |
| protected void initialize() { |
| super.initialize(); |
| joinAssociationPath = new CollectionValuedPathExpressionStateObject(this); |
| identificationVariable = new IdentificationVariableStateObject(this); |
| } |
| |
| @Override |
| public boolean isEquivalent(StateObject stateObject) { |
| |
| if (super.isEquivalent(stateObject)) { |
| JoinStateObject join = (JoinStateObject) stateObject; |
| return joinType.equals(join.joinType) && |
| areEquivalent(joinAssociationPath, join.joinAssociationPath) && |
| (as == join.as) && |
| identificationVariable.isEquivalent(join.identificationVariable); |
| } |
| |
| return false; |
| } |
| |
| /** |
| * Returns the segments in the state field path in order. |
| * |
| * @return An <code>Iterator</code> over the segments of the state field path |
| */ |
| public ListIterable<String> joinAssociationPaths() { |
| return joinAssociationPath.items(); |
| } |
| |
| /** |
| * Returns the number of segments in the path expression. |
| * |
| * @return The number of segments |
| */ |
| public int joinAssociationPathSize() { |
| return joinAssociationPath.itemsSize(); |
| } |
| |
| /** |
| * Makes sure the <code><b>AS</b></code> identifier is not specified. |
| */ |
| public void removeNot() { |
| if (as) { |
| setAs(false); |
| } |
| } |
| |
| /** |
| * Sets whether the <code><b>AS</b></code> identifier is used or not. |
| * |
| * @param as <code>true</code> if the <code><b>AS</b></code> identifier is part of the expression; |
| * <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 Join 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 Join parsed object} representing a <code><b>JOIN</b></code> |
| * expression |
| */ |
| public void setExpression(Join expression) { |
| super.setExpression(expression); |
| } |
| |
| /** |
| * Sets the name of the identification variable that defines the join association path. |
| * |
| * @param identificationVariable The new variable defining the join association path |
| */ |
| public void setIdentificationVariable(String identificationVariable) { |
| this.identificationVariable.setText(identificationVariable); |
| } |
| |
| /** |
| * Sets the {@link StateObject} representing the identification variable that starts the path |
| * expression, which can be a sample identification variable, a map value, map key or map entry |
| * expression. |
| * |
| * @param identificationVariable The root of the path expression |
| */ |
| public void setJoinAssociationIdentificationVariable(StateObject identificationVariable) { |
| joinAssociationPath.setIdentificationVariable(identificationVariable); |
| } |
| |
| /** |
| * Changes the path expression with the list of segments, the identification variable will also |
| * be updated with the first segment. |
| * |
| * @param path The new path expression |
| */ |
| public void setJoinAssociationPath(String path) { |
| joinAssociationPath.setPath(path); |
| } |
| |
| /** |
| * Changes the path expression with the list of segments, the identification variable will also |
| * be updated with the first segment. |
| * |
| * @param paths The new path expression |
| */ |
| public void setJoinAssociationPaths(ListIterator<String> paths) { |
| joinAssociationPath.setPaths(paths); |
| } |
| |
| /** |
| * Changes the path expression with the list of segments, the identification variable will also |
| * be updated with the first segment. |
| * |
| * @param paths The new path expression |
| */ |
| public void setJoinAssociationPaths(String[] paths) { |
| joinAssociationPath.setPaths(paths); |
| } |
| |
| /** |
| * Sets the joining type. |
| * |
| * @param joinType One of the joining types |
| */ |
| public void setJoinType(String joinType) { |
| validateJoinType(joinType); |
| String oldJoinType = this.joinType; |
| this.joinType = joinType; |
| firePropertyChanged(JOIN_TYPE_PROPERTY, oldJoinType, joinType); |
| } |
| |
| /** |
| * Toggles the usage of the <code><b>AS</b></code> identifier. |
| */ |
| public void toggleAs() { |
| setAs(!as); |
| } |
| |
| @Override |
| protected void toTextInternal(Appendable writer) throws IOException { |
| |
| writer.append(joinType); |
| writer.append(SPACE); |
| |
| joinAssociationPath.toString(writer); |
| writer.append(SPACE); |
| |
| if (as) { |
| writer.append(AS); |
| writer.append(SPACE); |
| } |
| |
| identificationVariable.toString(writer); |
| } |
| |
| /** |
| * Validates the given join type. |
| * |
| * @param joinType One of the possible joining types |
| */ |
| protected void validateJoinType(String joinType) { |
| Assert.isValid( |
| joinType, |
| "The join type is not valid", |
| JOIN, LEFT_JOIN, LEFT_OUTER_JOIN, INNER_JOIN, |
| JOIN_FETCH, LEFT_JOIN_FETCH, LEFT_OUTER_JOIN_FETCH, INNER_JOIN_FETCH |
| ); |
| } |
| } |