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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
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package org.apache.cayenne.access;
import java.util.List;
import org.apache.cayenne.CayenneRuntimeException;
import org.apache.cayenne.Fault;
import org.apache.cayenne.ObjectContext;
import org.apache.cayenne.PersistenceState;
import org.apache.cayenne.Persistent;
import org.apache.cayenne.query.RelationshipQuery;
/**
* @since 3.0
*/
public class ToOneFault extends Fault {
/**
* Resolves this fault to a DataObject.
*/
@Override
public Object resolveFault(Persistent sourceObject, String relationshipName) {
if (sourceObject.getObjectContext() == null) {
throw new IllegalStateException(
"Null ObjectContext. Can't read a to-one relationship '"
+ relationshipName
+ "' for an object with ID: "
+ sourceObject.getObjectId());
}
int state = sourceObject.getPersistenceState();
if (state == PersistenceState.NEW) {
return null;
}
Object target = doResolveFault(sourceObject, relationshipName);
// must update the diff for the object
ObjectContext context = sourceObject.getObjectContext();
if ((state == PersistenceState.MODIFIED || state == PersistenceState.DELETED)
&& context instanceof DataContext) {
ObjectDiff diff = ((DataContext) context)
.getObjectStore()
.getChangesByObjectId()
.get(sourceObject.getObjectId());
if (diff != null) {
diff.updateArcSnapshot(relationshipName, (Persistent) target);
}
}
return target;
}
Object doResolveFault(Persistent sourceObject, String relationshipName) {
RelationshipQuery query = new RelationshipQuery(
sourceObject.getObjectId(),
relationshipName,
false);
List objects = sourceObject.getObjectContext().performQuery(query);
if (objects.isEmpty()) {
return null;
}
else if (objects.size() == 1) {
return objects.get(0);
}
else {
throw new CayenneRuntimeException("Error resolving to-one fault. "
+ "More than one object found. "
+ "Source Id: "
+ sourceObject.getObjectId()
+ ", relationship: "
+ relationshipName);
}
}
}