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. TODO
28 * {@link #DependencyTreeInverseIterator(DependencyNode)} is costly, a better implementation would move the cost to
29 * {@link #next()}
30 *
31 * @author <a href="mailto:carlos@apache.org">Carlos Sanchez</a>
32 * @version $Id: DependencyTreeInverseIterator.java 1595642 2014-05-18 17:32:08Z jvanzyl $
33 */
34 public class DependencyTreeInverseIterator
35 implements Iterator<DependencyNode>
36 {
37 private Stack<DependencyNode> nodesToProcess = new Stack<DependencyNode>();
38
39 public DependencyTreeInverseIterator( DependencyNode rootNode )
40 {
41 DependencyTreePreorderIterator it = new DependencyTreePreorderIterator( rootNode );
42 while ( it.hasNext() )
43 {
44 nodesToProcess.push( it.next() );
45 }
46 }
47
48 public boolean hasNext()
49 {
50 return !nodesToProcess.isEmpty();
51 }
52
53 public DependencyNode next()
54 {
55 if ( !hasNext() )
56 {
57 throw new NoSuchElementException();
58 }
59 return nodesToProcess.pop();
60 }
61
62 /**
63 * @throws UnsupportedOperationException
64 */
65 public void remove()
66 {
67 throw new UnsupportedOperationException();
68 }
69 }