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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.checks.sizes;
21  
22  import java.util.Arrays;
23  import java.util.concurrent.atomic.AtomicInteger;
24  
25  import com.puppycrawl.tools.checkstyle.StatelessCheck;
26  import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
27  import com.puppycrawl.tools.checkstyle.api.DetailAST;
28  import com.puppycrawl.tools.checkstyle.api.TokenTypes;
29  import com.puppycrawl.tools.checkstyle.checks.naming.AccessModifierOption;
30  import com.puppycrawl.tools.checkstyle.utils.CheckUtil;
31  import com.puppycrawl.tools.checkstyle.utils.TokenUtil;
32  
33  /**
34   * <p>
35   * Checks the number of record components in the
36   * <a href="https://docs.oracle.com/javase/specs/jls/se14/preview/specs/records-jls.html#jls-8.10.1">
37   * header</a> of a record definition.
38   * </p>
39   * <ul>
40   * <li>
41   * Property {@code accessModifiers} - Access modifiers of record definitions where
42   * the number of record components should be checked.
43   * Type is {@code com.puppycrawl.tools.checkstyle.checks.naming.AccessModifierOption[]}.
44   * Default value is {@code public, protected, package, private}.
45   * </li>
46   * <li>
47   * Property {@code max} - Specify the maximum number of components allowed in the header of a
48   * record definition.
49   * Type is {@code int}.
50   * Default value is {@code 8}.
51   * </li>
52   * </ul>
53   * <p>
54   * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
55   * </p>
56   * <p>
57   * Violation Message Keys:
58   * </p>
59   * <ul>
60   * <li>
61   * {@code too.many.components}
62   * </li>
63   * </ul>
64   *
65   * @since 8.36
66   */
67  @StatelessCheck
68  public class RecordComponentNumberCheck extends AbstractCheck {
69  
70      /**
71       * A key is pointing to the warning message text in "messages.properties"
72       * file.
73       */
74      public static final String MSG_KEY = "too.many.components";
75  
76      /** Default maximum number of allowed components. */
77      private static final int DEFAULT_MAX_COMPONENTS = 8;
78  
79      /** Specify the maximum number of components allowed in the header of a record definition. */
80      private int max = DEFAULT_MAX_COMPONENTS;
81  
82      /**
83       * Access modifiers of record definitions where the number
84       * of record components should be checked.
85       */
86      private AccessModifierOption[] accessModifiers = {
87          AccessModifierOption.PUBLIC,
88          AccessModifierOption.PROTECTED,
89          AccessModifierOption.PACKAGE,
90          AccessModifierOption.PRIVATE,
91      };
92  
93      /**
94       * Setter to specify the maximum number of components allowed in the header
95       * of a record definition.
96       *
97       * @param value the maximum allowed.
98       * @since 8.36
99       */
100     public void setMax(int value) {
101         max = value;
102     }
103 
104     /**
105      * Setter to access modifiers of record definitions where the number of record
106      * components should be checked.
107      *
108      * @param accessModifiers access modifiers of record definitions which should be checked.
109      * @since 8.36
110      */
111     public void setAccessModifiers(AccessModifierOption... accessModifiers) {
112         this.accessModifiers =
113                 Arrays.copyOf(accessModifiers, accessModifiers.length);
114     }
115 
116     @Override
117     public int[] getDefaultTokens() {
118         return getAcceptableTokens();
119     }
120 
121     @Override
122     public int[] getAcceptableTokens() {
123         return new int[] {
124             TokenTypes.RECORD_DEF,
125         };
126     }
127 
128     @Override
129     public int[] getRequiredTokens() {
130         return getAcceptableTokens();
131     }
132 
133     @Override
134     public void visitToken(DetailAST ast) {
135         final AccessModifierOption accessModifier =
136             CheckUtil.getAccessModifierFromModifiersToken(ast);
137 
138         if (matchAccessModifiers(accessModifier)) {
139             final DetailAST recordComponents =
140                 ast.findFirstToken(TokenTypes.RECORD_COMPONENTS);
141             final int componentCount = countComponents(recordComponents);
142 
143             if (componentCount > max) {
144                 log(ast, MSG_KEY, componentCount, max);
145             }
146         }
147     }
148 
149     /**
150      * Method to count the number of record components in this record definition.
151      *
152      * @param recordComponents the ast to check
153      * @return the number of record components in this record definition
154      */
155     private static int countComponents(DetailAST recordComponents) {
156         final AtomicInteger count = new AtomicInteger(0);
157         TokenUtil.forEachChild(recordComponents,
158             TokenTypes.RECORD_COMPONENT_DEF,
159             node -> count.getAndIncrement());
160         return count.get();
161     }
162 
163     /**
164      * Checks whether a record definition has the correct access modifier to be checked.
165      *
166      * @param accessModifier the access modifier of the record definition.
167      * @return whether the record definition matches the expected access modifier.
168      */
169     private boolean matchAccessModifiers(final AccessModifierOption accessModifier) {
170         return Arrays.stream(accessModifiers)
171                 .anyMatch(modifier -> modifier == accessModifier);
172     }
173 }