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1   ///////////////////////////////////////////////////////////////////////////////////////////////
2   // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
3   // Copyright (C) 2001-2024 the original author or authors.
4   //
5   // This library is free software; you can redistribute it and/or
6   // modify it under the terms of the GNU Lesser General Public
7   // License as published by the Free Software Foundation; either
8   // version 2.1 of the License, or (at your option) any later version.
9   //
10  // This library is distributed in the hope that it will be useful,
11  // but WITHOUT ANY WARRANTY; without even the implied warranty of
12  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  // Lesser General Public License for more details.
14  //
15  // You should have received a copy of the GNU Lesser General Public
16  // License along with this library; if not, write to the Free Software
17  // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18  ///////////////////////////////////////////////////////////////////////////////////////////////
19  
20  package com.puppycrawl.tools.checkstyle.filters;
21  
22  import java.util.Collections;
23  import java.util.HashSet;
24  import java.util.Objects;
25  import java.util.Set;
26  import java.util.StringTokenizer;
27  
28  /**
29   * <div>
30   * This filter element is immutable and accepts an integer that matches a CSV value, where
31   * each value is an integer or a range of integers.
32   * </div>
33   */
34  class CsvFilterElement implements IntFilterElement {
35  
36      /** Filter set. */
37      private final Set<IntFilterElement> filters = new HashSet<>();
38  
39      /**
40       * Constructs a {@code CsvFilterElement} from a CSV, Comma-Separated Values,
41       * string. Each value is an integer, or a range of integers. A range of
42       * integers is of the form integer-integer, such as 1-10.
43       * Note: integers must be non-negative.
44       *
45       * @param pattern the CSV string.
46       * @throws NumberFormatException if a component substring does not
47       *     contain a parsable integer.
48       */
49      /* package */ CsvFilterElement(String pattern) {
50          final StringTokenizer tokenizer = new StringTokenizer(pattern, ",");
51          while (tokenizer.hasMoreTokens()) {
52              final String token = tokenizer.nextToken().trim();
53              final int index = token.indexOf('-');
54              if (index == -1) {
55                  final int matchValue = Integer.parseInt(token);
56                  addFilter(new IntMatchFilterElement(matchValue));
57              }
58              else {
59                  final int lowerBound =
60                      Integer.parseInt(token.substring(0, index));
61                  final int upperBound =
62                      Integer.parseInt(token.substring(index + 1));
63                  addFilter(new IntRangeFilterElement(lowerBound, upperBound));
64              }
65          }
66      }
67  
68      /**
69       * Adds a IntFilterElement to the set.
70       *
71       * @param filter the IntFilterElement to add.
72       */
73      private void addFilter(IntFilterElement filter) {
74          filters.add(filter);
75      }
76  
77      /**
78       * Returns the IntFilters of the filter set.
79       *
80       * @return the IntFilters of the filter set.
81       */
82      protected Set<IntFilterElement> getFilters() {
83          return Collections.unmodifiableSet(filters);
84      }
85  
86      /**
87       * Determines whether an Integer matches a CSV integer value.
88       *
89       * @param intValue the Integer to check.
90       * @return true if intValue is an Integer that matches a CSV value.
91       */
92      @Override
93      public boolean accept(int intValue) {
94          boolean result = false;
95          for (IntFilterElement filter : getFilters()) {
96              if (filter.accept(intValue)) {
97                  result = true;
98                  break;
99              }
100         }
101         return result;
102     }
103 
104     @Override
105     public boolean equals(Object object) {
106         if (this == object) {
107             return true;
108         }
109         if (object == null || getClass() != object.getClass()) {
110             return false;
111         }
112         final CsvFilterElement csvFilter = (CsvFilterElement) object;
113         return Objects.equals(filters, csvFilter.filters);
114     }
115 
116     @Override
117     public int hashCode() {
118         return Objects.hash(filters);
119     }
120 
121 }