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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *     https://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.apache.commons.configuration2;
18  
19  import org.apache.commons.configuration2.tree.ConfigurationNodeVisitorAdapter;
20  import org.apache.commons.configuration2.tree.NodeHandler;
21  
22  /**
23   * <p>
24   * A specialized {@code NodeVisitor} implementation which searches for a specific node in a hierarchy.
25   * </p>
26   *
27   * @param <T> the type of the nodes to be visited
28   */
29  final class FindNodeVisitor<T> extends ConfigurationNodeVisitorAdapter<T> {
30  
31      /** The node to be searched for. */
32      private final T searchNode;
33  
34      /** A flag whether the node was found. */
35      private boolean found;
36  
37      /**
38       * Creates a new instance of {@code FindNodeVisitor} and sets the node to be searched for.
39       *
40       * @param node the search node
41       */
42      public FindNodeVisitor(final T node) {
43          searchNode = node;
44      }
45  
46      /**
47       * Returns a flag whether the search node was found in the last search operation.
48       *
49       * @return <strong>true</strong> if the search node was found; <strong>false</strong> otherwise
50       */
51      public boolean isFound() {
52          return found;
53      }
54  
55      /**
56       * Resets this visitor. This method sets the {@code found} property to <strong>false</strong> again, so that this instance can be
57       * used to inspect another nodes hierarchy.
58       */
59      public void reset() {
60          found = false;
61      }
62  
63      /**
64       * {@inheritDoc} This implementation returns <strong>true</strong> as soon as the node was found.
65       */
66      @Override
67      public boolean terminate() {
68          return found;
69      }
70  
71      @Override
72      public void visitBeforeChildren(final T node, final NodeHandler<T> handler) {
73          if (node.equals(searchNode)) {
74              found = true;
75          }
76      }
77  }