org.apache.openjpa.lib.graph.GraphVisitor Maven / Gradle / Ivy
/*
* 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.lib.graph;
/**
* A helper interface that allows third parties to be notified of
* graph events during graph traversals
*
* @author Steve Kim
* @since 1.0.0
*/
public interface GraphVisitor {
/**
* May not be called. The meaning of this method is dependent
* on the traversal being used. See each appropriate graph
* walker for details.
*/
void nodeSeen(Object node);
/**
* will only be called once per node
*/
void nodeVisited(Object node);
/**
* may visit the node twice (both sides)
*/
void edgeVisited(Edge edge);
}