| /* |
| * 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 org.eclipse.persistence.jpa.jpql.parser.CollectionValuedPathExpression; |
| import org.eclipse.persistence.jpa.jpql.tools.TypeHelper; |
| import org.eclipse.persistence.jpa.jpql.tools.spi.IManagedType; |
| import org.eclipse.persistence.jpa.jpql.tools.spi.IMapping; |
| import org.eclipse.persistence.jpa.jpql.tools.spi.IType; |
| import org.eclipse.persistence.jpa.jpql.tools.spi.ITypeDeclaration; |
| |
| /** |
| * A collection-valued field is designated by the name of an association field in a one-to-many or a |
| * many-to-many relationship or by the name of an element collection field. The type of a |
| * collection-valued field is a collection of values of the abstract schema type of the related |
| * entity or element type. |
| * |
| * <div><p><b>BNF:</b> <code>collection_valued_path_expression ::= general_identification_variable.{single_valued_object_field.}*collection_valued_field</code></p></div> |
| * |
| * @see CollectionValuedPathExpression |
| * |
| * @version 2.4 |
| * @since 2.4 |
| * @author Pascal Filion |
| */ |
| public class CollectionValuedPathExpressionStateObject extends AbstractPathExpressionStateObject { |
| |
| /** |
| * Creates a new <code>CollectionValuedPathExpressionStateObject</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 CollectionValuedPathExpressionStateObject(StateObject parent) { |
| super(parent); |
| } |
| |
| /** |
| * Creates a new <code>CollectionValuedPathExpressionStateObject</code>. |
| * |
| * @param parent The parent of this state object, which cannot be <code>null</code> |
| * @param path The collection-valued path expression |
| * @exception NullPointerException The given parent cannot be <code>null</code> |
| */ |
| public CollectionValuedPathExpressionStateObject(StateObject parent, String path) { |
| super(parent, path); |
| } |
| |
| @Override |
| public void accept(StateObjectVisitor visitor) { |
| visitor.visit(this); |
| } |
| |
| @Override |
| public CollectionValuedPathExpression getExpression() { |
| return (CollectionValuedPathExpression) super.getExpression(); |
| } |
| |
| @Override |
| protected IManagedType resolveManagedType() { |
| |
| IMapping mapping = getMapping(); |
| |
| if (mapping == null) { |
| return null; |
| } |
| |
| TypeHelper typeHelper = getTypeHelper(); |
| ITypeDeclaration typeDeclaration = mapping.getTypeDeclaration(); |
| IType type = typeDeclaration.getType(); |
| |
| // Collection type cannot be traversed |
| // Example: SELECT e.employees. FROM Employee e where employees is a collection, |
| // it cannot be traversed |
| if (typeHelper.isCollectionType(type)) { |
| return null; |
| } |
| |
| // Primitive types cannot have a managed type |
| if (typeHelper.isPrimitiveType(type)) { |
| return null; |
| } |
| |
| // Retrieve the corresponding managed type for the mapping's type |
| return getManagedTypeProvider().getManagedType(type); |
| } |
| |
| @Override |
| protected IType resolveType() { |
| |
| TypeHelper typeHelper = getTypeHelper(); |
| ITypeDeclaration typeDeclaration = getTypeDeclaration(); |
| IType type = typeDeclaration.getType(); |
| |
| // For a collection type, return the first type parameter |
| if (typeHelper.isCollectionType(type)) { |
| |
| ITypeDeclaration[] typeParameters = typeDeclaration.getTypeParameters(); |
| |
| if (typeParameters.length > 0) { |
| type = typeParameters[0].getType(); |
| } |
| } |
| // For a map type, by default the value is the actual type to return |
| else if (typeHelper.isMapType(type)) { |
| |
| ITypeDeclaration[] typeParameters = typeDeclaration.getTypeParameters(); |
| |
| if (typeParameters.length == 2) { |
| type = typeParameters[1].getType(); |
| } |
| } |
| |
| // A collection-valued path expression should not reference a primitive, |
| // however, in an invalid query, this could potentially happen and the API |
| // only deals with the primitive wrapper type |
| return typeHelper.convertPrimitive(type); |
| } |
| |
| /** |
| * Keeps a reference of the {@link CollectionValuedPathExpression 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 CollectionValuedPathExpression parsed object} representing a |
| * collection-valued path expression |
| */ |
| public void setExpression(CollectionValuedPathExpression expression) { |
| super.setExpression(expression); |
| } |
| } |