| /* |
| * Copyright (c) 2011, 2020 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: |
| // ailitchev - Bug 244124 - New support for loading |
| package org.eclipse.persistence.queries; |
| |
| import org.eclipse.persistence.core.queries.CoreAttributeGroup; |
| |
| /** |
| * <b>Purpose</b>: Used to load specified relationship attributes and nested |
| * relationship attributes. |
| * <p> |
| * A LoadGroup can be configured for use on a query using |
| * {@link ObjectLevelReadQuery#setLoadGroup(LoadGroup)} or in the case of JPA |
| * users with LOAD_GROUP query hint. Alternatively a {@link FetchGroup} could be |
| * used with {@link FetchGroup#shouldLoad()} set to true and the FetchGroup |
| * configured on a query be executed. |
| * |
| * @see FetchGroup |
| * |
| * @author ailitchev |
| * @since Eclipselink 2.1 |
| */ |
| public class LoadGroup extends AttributeGroup { |
| |
| protected Boolean isConcurrent; |
| |
| public LoadGroup() { |
| super(); |
| } |
| |
| public LoadGroup(String name) { |
| super(name); |
| } |
| |
| @Override |
| protected LoadGroup newGroup(String name, CoreAttributeGroup parent) { |
| return new LoadGroup(name); |
| } |
| |
| @Override |
| public boolean isLoadGroup() { |
| return true; |
| } |
| |
| @Override |
| public LoadGroup clone() { |
| return (LoadGroup)super.clone(); |
| } |
| |
| /** |
| * Returns LoadGroup corresponding to the passed (possibly nested) attribute. |
| */ |
| @Override |
| public LoadGroup getGroup(String attributeNameOrPath) { |
| return (LoadGroup)super.getGroup(attributeNameOrPath); |
| } |
| |
| @Override |
| public void addAttribute(String attributeNameOrPath, CoreAttributeGroup group) { |
| super.addAttribute(attributeNameOrPath, (group != null ? ((AttributeGroup)group).toLoadGroup() : null)); |
| } |
| |
| public void addAttribute(String attributeNameOrPath, LoadGroup group) { |
| super.addAttribute(attributeNameOrPath, group); |
| } |
| |
| /** |
| * INTERNAL: |
| * Return if the load group should load its relationships concurrently. |
| */ |
| public Boolean getIsConcurrent() { |
| return this.isConcurrent; |
| } |
| |
| /** |
| * ADVANCED: |
| * Return if the load group should load its relationships concurrently. |
| * This will use the session's server platform's thread pool. |
| * Each of the query results objects relationships will be loaded on a different thread. |
| * This can improve performance by processing many queries at once. |
| * Concurrent load is only supported when a shared cache is used. |
| */ |
| @Override |
| public boolean isConcurrent() { |
| if (this.isConcurrent == null) { |
| return false; |
| } |
| return this.isConcurrent.booleanValue(); |
| } |
| |
| /** |
| * ADVANCED: |
| * Set if the load group should load its relationships concurrently. |
| * This will use the session's server platform's thread pool. |
| * Each of the query results objects relationships will be loaded on a different thread. |
| * This can improve performance by processing many queries at once. |
| * Concurrent load is only supported when a shared cache is used. |
| */ |
| public void setIsConcurrent(Boolean isConcurrent) { |
| this.isConcurrent = isConcurrent; |
| } |
| } |