1 ///////////////////////////////////////////////////////////////////////////////////////////////
2 // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
3 // Copyright (C) 2001-2025 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
24 import com.puppycrawl.tools.checkstyle.StatelessCheck;
25 import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
26 import com.puppycrawl.tools.checkstyle.api.DetailAST;
27 import com.puppycrawl.tools.checkstyle.api.TokenTypes;
28 import com.puppycrawl.tools.checkstyle.checks.naming.AccessModifierOption;
29 import com.puppycrawl.tools.checkstyle.utils.CheckUtil;
30
31 /**
32 * <div>
33 * Checks the number of record components in the
34 * <a href="https://docs.oracle.com/javase/specs/jls/se14/preview/specs/records-jls.html#jls-8.10.1">
35 * header</a> of a record definition.
36 * </div>
37 *
38 * @since 8.36
39 */
40 @StatelessCheck
41 public class RecordComponentNumberCheck extends AbstractCheck {
42
43 /**
44 * A key is pointing to the warning message text in "messages.properties"
45 * file.
46 */
47 public static final String MSG_KEY = "too.many.components";
48
49 /** Default maximum number of allowed components. */
50 private static final int DEFAULT_MAX_COMPONENTS = 8;
51
52 /** Specify the maximum number of components allowed in the header of a record definition. */
53 private int max = DEFAULT_MAX_COMPONENTS;
54
55 /**
56 * Access modifiers of record definitions where the number
57 * of record components should be checked.
58 */
59 private AccessModifierOption[] accessModifiers = {
60 AccessModifierOption.PUBLIC,
61 AccessModifierOption.PROTECTED,
62 AccessModifierOption.PACKAGE,
63 AccessModifierOption.PRIVATE,
64 };
65
66 /**
67 * Setter to specify the maximum number of components allowed in the header
68 * of a record definition.
69 *
70 * @param value the maximum allowed.
71 * @since 8.36
72 */
73 public void setMax(int value) {
74 max = value;
75 }
76
77 /**
78 * Setter to access modifiers of record definitions where the number of record
79 * components should be checked.
80 *
81 * @param accessModifiers access modifiers of record definitions which should be checked.
82 * @since 8.36
83 */
84 public void setAccessModifiers(AccessModifierOption... accessModifiers) {
85 this.accessModifiers =
86 Arrays.copyOf(accessModifiers, accessModifiers.length);
87 }
88
89 @Override
90 public int[] getDefaultTokens() {
91 return getAcceptableTokens();
92 }
93
94 @Override
95 public int[] getAcceptableTokens() {
96 return new int[] {
97 TokenTypes.RECORD_DEF,
98 };
99 }
100
101 @Override
102 public int[] getRequiredTokens() {
103 return getAcceptableTokens();
104 }
105
106 @Override
107 public void visitToken(DetailAST ast) {
108 final AccessModifierOption accessModifier =
109 CheckUtil.getAccessModifierFromModifiersToken(ast);
110
111 if (matchAccessModifiers(accessModifier)) {
112 final DetailAST recordComponents =
113 ast.findFirstToken(TokenTypes.RECORD_COMPONENTS);
114 final int componentCount = countComponents(recordComponents);
115
116 if (componentCount > max) {
117 log(ast, MSG_KEY, componentCount, max);
118 }
119 }
120 }
121
122 /**
123 * Method to count the number of record components in this record definition.
124 *
125 * @param recordComponents the ast to check
126 * @return the number of record components in this record definition
127 */
128 private static int countComponents(DetailAST recordComponents) {
129 return recordComponents.getChildCount(TokenTypes.RECORD_COMPONENT_DEF);
130 }
131
132 /**
133 * Checks whether a record definition has the correct access modifier to be checked.
134 *
135 * @param accessModifier the access modifier of the record definition.
136 * @return whether the record definition matches the expected access modifier.
137 */
138 private boolean matchAccessModifiers(final AccessModifierOption accessModifier) {
139 return Arrays.stream(accessModifiers)
140 .anyMatch(modifier -> modifier == accessModifier);
141 }
142 }