/*
* 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.persistence.graph;
import java.util.AbstractSet;
import java.util.Set;
/**
* Abstract implementation of a {@linkplain Graph} borrows from {@link AbstractSet abstract} implementation of
* {@link Set}. The extended {@link Set#remove(Object) remove()} semantics accounts for
* {@link Graph#delink(Object, Object) removal} of all relationship to the removed element.
*
* @author Pinaki Poddar
*
* @param <E> type of element of the graph.
*/
public abstract class AbstractGraph<E> extends AbstractSet<E> implements Graph<E> {
/**
* Removing an element from this graph has the side effect of removing all
* relations directed to the removed element.
*/
@Override
public boolean remove(Object e) {
E node = (E)e;
Set<Relation<E, E>> rs = getRelationsTo(node);
for (Relation<E,E> r : rs) {
delink(r.getSource(), node);
}
return super.remove(e);
}
}