001/* 002 * Licensed to the Apache Software Foundation (ASF) under one 003 * or more contributor license agreements. See the NOTICE file 004 * distributed with this work for additional information 005 * regarding copyright ownership. The ASF licenses this file 006 * to you under the Apache License, Version 2.0 (the 007 * "License"); you may not use this file except in compliance 008 * with the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, 013 * software distributed under the License is distributed on an 014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 015 * KIND, either express or implied. See the License for the 016 * specific language governing permissions and limitations 017 * under the License. 018 */ 019package org.apache.maven.enforcer.rules.utils; 020 021import java.util.HashMap; 022import java.util.Map; 023import java.util.Stack; 024 025import org.eclipse.aether.graph.DependencyNode; 026import org.eclipse.aether.graph.DependencyVisitor; 027 028/** 029 * A {@link DependencyVisitor} building a map of parent nodes 030 */ 031public class ParentsVisitor implements DependencyVisitor, ParentNodeProvider { 032 033 private final Map<DependencyNode, DependencyNode> parents = new HashMap<>(); 034 private final Stack<DependencyNode> parentStack = new Stack<>(); 035 036 @Override 037 public DependencyNode getParent(DependencyNode node) { 038 return parents.get(node); 039 } 040 041 @Override 042 public boolean visitEnter(DependencyNode node) { 043 parents.put(node, parentStack.isEmpty() ? null : parentStack.peek()); 044 parentStack.push(node); 045 return true; 046 } 047 048 @Override 049 public boolean visitLeave(DependencyNode node) { 050 parentStack.pop(); 051 return true; 052 } 053}