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/*
* Copyright (c) 1998, 2018 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 from Oracle TopLink
package org.eclipse.persistence.sdo;
import commonj.sdo.DataObject;
import commonj.sdo.ChangeSummary;
import commonj.sdo.Type;
import commonj.sdo.DataGraph;
import commonj.sdo.helper.HelperContext;
import commonj.sdo.impl.HelperProvider;
/**
* Purpose:A data graph is used to package a graph of {@link DataObject data objects} along with their
* metadata, that is, data describing the data.
* A data graph also contains a {@link #getChangeSummary change summary}
* which is used to record changes made to the objects in the graph.
*/
public class SDODataGraph implements DataGraph {
private HelperContext helperContext;
private SDODataObject rootObject;
private SDOChangeSummary changeSummary;
public SDODataGraph(HelperContext helperContext) {
super();
if(null == helperContext) {
this.helperContext = HelperProvider.getDefaultContext();
} else {
this.helperContext = helperContext;
}
this.changeSummary = new SDOChangeSummary(this, helperContext);
}
/**
* Returns the root {@link DataObject data object} of this data graph.
* @return the root data object.
* @see DataObject#getDataGraph
*/
public SDODataObject getRootObject() {
return this.rootObject;
}
/**
* Returns the {@link ChangeSummary change summary} associated with this data graph.
* @return the change summary.
* @see ChangeSummary#getDataGraph
*/
public SDOChangeSummary getChangeSummary() {
return this.changeSummary;
}
/**
* Returns the {@link Type type} with the given the {@link Type#getURI() URI},
* or contained by the resource at the given URI,
* and with the given {@link Type#getName name}.
* @param uri the namespace URI of a type or the location URI of a resource containing a type.
* @param typeName name of a type.
* @return the type with the corresponding namespace and name.
*/
public SDOType getType(String uri, String typeName) {
return (SDOType) helperContext.getTypeHelper().getType(uri, typeName);
}
/**
* Creates a new root data object of the {@link #getType specified type}.
* An exception is thrown if a root object exists.
* @param namespaceURI namespace of the type.
* @param typeName name of the type.
* @return the new root.
* @throws IllegalStateException if the root object already exists.
* @see #createRootObject(Type)
* @see #getType(String, String)
*/
public SDODataObject createRootObject(String namespaceURI, String typeName) {
if(null != rootObject) {
throw new IllegalStateException();
}
rootObject = (SDODataObject) helperContext.getDataFactory().create(namespaceURI, typeName);
rootObject.setDataGraph(this);
rootObject._setChangeSummary(changeSummary);
changeSummary.setRootDataObject(rootObject);
return rootObject;
}
/**
* Creates a new root data object of the specified type.
* An exception is thrown if a root object exists.
* @param type the type of the new root.
* @return the new root.
* @throws IllegalStateException if the root object already exists.
* @see #createRootObject(String, String)
*/
public SDODataObject createRootObject(Type type) {
if(null != rootObject) {
throw new IllegalStateException();
}
rootObject = (SDODataObject) helperContext.getDataFactory().create(type);
rootObject.setDataGraph(this);
rootObject._setChangeSummary(changeSummary);
changeSummary.setRootDataObject(rootObject);
return rootObject;
}
}