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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *   http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing,
13   * software distributed under the License is distributed on an
14   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   * KIND, either express or implied.  See the License for the
16   * specific language governing permissions and limitations
17   * under the License.
18   */
19  package org.apache.maven.doxia.sink.impl;
20  
21  import java.util.HashSet;
22  import java.util.Set;
23  
24  import org.apache.maven.doxia.sink.Sink;
25  import org.apache.maven.doxia.sink.SinkEventAttributes;
26  import org.slf4j.Logger;
27  import org.slf4j.LoggerFactory;
28  
29  /**
30   * Validates that each anchor name only appears once per document. Otherwise logs a warning.
31   */
32  public class UniqueAnchorNamesValidator extends SinkWrapper {
33  
34      private static final Logger LOGGER = LoggerFactory.getLogger(UniqueAnchorNamesValidator.class);
35  
36      private final Set<String> usedAnchorNames;
37  
38      public UniqueAnchorNamesValidator(Sink sink) {
39          super(sink);
40          usedAnchorNames = new HashSet<>();
41      }
42  
43      @Override
44      public void anchor(String name, SinkEventAttributes attributes) {
45          // assume that other anchor method signature calls this method under the hood in all relevant sink
46          // implementations
47          super.anchor(name, attributes);
48          if (!usedAnchorNames.add(name)) {
49              LOGGER.warn("{}Anchor name \"{}\" used more than once", getLocationLogPrefix(), name);
50          }
51      }
52  }