1 package org.apache.maven.shared.dependency.tree; 2 3 /* 4 * Licensed to the Apache Software Foundation (ASF) under one 5 * or more contributor license agreements. See the NOTICE file 6 * distributed with this work for additional information 7 * regarding copyright ownership. The ASF licenses this file 8 * to you under the Apache License, Version 2.0 (the 9 * "License"); you may not use this file except in compliance 10 * with the License. You may obtain a copy of the License at 11 * 12 * http://www.apache.org/licenses/LICENSE-2.0 13 * 14 * Unless required by applicable law or agreed to in writing, 15 * software distributed under the License is distributed on an 16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 17 * KIND, either express or implied. See the License for the 18 * specific language governing permissions and limitations 19 * under the License. 20 */ 21 22 import java.util.Iterator; 23 import java.util.NoSuchElementException; 24 import java.util.Stack; 25 26 /** 27 * {@link Iterator} for {@link DependencyNode} implementing a traversal from leaves to root. 28 * 29 * TODO {@link #DependencyTreeInverseIterator(DependencyNode)} is costly, 30 * a better implementation would move the cost to {@link #next()} 31 * 32 * @author <a href="mailto:carlos@apache.org">Carlos Sanchez</a> 33 * @version $Id: DependencyTreeInverseIterator.java 1100703 2011-05-08 08:27:33Z hboutemy $ 34 */ 35 public class DependencyTreeInverseIterator 36 implements Iterator<DependencyNode> 37 { 38 private Stack<DependencyNode> nodesToProcess = new Stack<DependencyNode>(); 39 40 public DependencyTreeInverseIterator( DependencyNode rootNode ) 41 { 42 DependencyTreePreorderIterator it = new DependencyTreePreorderIterator( rootNode ); 43 while ( it.hasNext() ) 44 { 45 nodesToProcess.push( it.next() ); 46 } 47 } 48 49 public boolean hasNext() 50 { 51 return !nodesToProcess.isEmpty(); 52 } 53 54 public DependencyNode next() 55 { 56 if ( !hasNext() ) 57 { 58 throw new NoSuchElementException(); 59 } 60 return nodesToProcess.pop(); 61 } 62 63 /** 64 * @throws UnsupportedOperationException 65 */ 66 public void remove() 67 { 68 throw new UnsupportedOperationException(); 69 } 70 }