/*
* 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
* under the License.
*/
package org.apache.openjpa.meta;
/**
* Comparator that keeps metadatas in inheritance order. Also places relation
* types used as primary keys before the primary key field owner types.
*
* @author Abe White
*/
public class MetaDataInheritanceComparator
extends InheritanceComparator {
protected Class toClass(Object elem) {
if (elem == null)
return null;
return ((ClassMetaData) elem).getDescribedType();
}
public int compare(Object o1, Object o2) {
if (o1 == o2)
return 0;
if (o1 == null)
return -1;
if (o2 == null)
return 1;
ClassMetaData m1 = (ClassMetaData) o1;
ClassMetaData m2 = (ClassMetaData) o2;
FieldMetaData[] fmds = m1.getDeclaredFields();
for (int i = 0; i < fmds.length; i++) {
if (fmds[i].isPrimaryKey() && m2.getDescribedType().
isAssignableFrom(fmds[i].getDeclaredType()))
return 1;
}
fmds = m2.getDeclaredFields();
for (int i = 0; i < fmds.length; i++) {
if (fmds[i].isPrimaryKey() && m1.getDescribedType().
isAssignableFrom(fmds[i].getDeclaredType()))
return -1;
}
return super.compare(o1, o2);
}
}