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.naming;
21
22 import com.puppycrawl.tools.checkstyle.api.DetailAST;
23 import com.puppycrawl.tools.checkstyle.api.TokenTypes;
24 import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
25 import com.puppycrawl.tools.checkstyle.utils.ScopeUtil;
26
27 /**
28 * <div>
29 * Checks that local final variable names conform to a specified pattern.
30 * A catch parameter and resources in try statements
31 * are considered to be a local, final variables.
32 * </div>
33 *
34 * <p>
35 * This check does not support final pattern variables. Instead, use
36 * <a href="https://checkstyle.org/checks/naming/patternvariablename.html#PatternVariableName">
37 * PatternVariableName</a>.
38 * </p>
39 * <ul>
40 * <li>
41 * Property {@code format} - Sets the pattern to match valid identifiers.
42 * Type is {@code java.util.regex.Pattern}.
43 * Default value is {@code "^([a-z][a-zA-Z0-9]*|_)$"}.
44 * </li>
45 * <li>
46 * Property {@code tokens} - tokens to check
47 * Type is {@code java.lang.String[]}.
48 * Validation type is {@code tokenSet}.
49 * Default value is:
50 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#VARIABLE_DEF">
51 * VARIABLE_DEF</a>,
52 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#PARAMETER_DEF">
53 * PARAMETER_DEF</a>,
54 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#RESOURCE">
55 * RESOURCE</a>.
56 * </li>
57 * </ul>
58 *
59 * <p>
60 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
61 * </p>
62 *
63 * <p>
64 * Violation Message Keys:
65 * </p>
66 * <ul>
67 * <li>
68 * {@code name.invalidPattern}
69 * </li>
70 * </ul>
71 *
72 * @since 3.0
73 */
74 public class LocalFinalVariableNameCheck
75 extends AbstractNameCheck {
76
77 /** Creates a new {@code LocalFinalVariableNameCheck} instance. */
78 public LocalFinalVariableNameCheck() {
79 super("^([a-z][a-zA-Z0-9]*|_)$");
80 }
81
82 @Override
83 public int[] getDefaultTokens() {
84 return getAcceptableTokens();
85 }
86
87 @Override
88 public int[] getAcceptableTokens() {
89 return new int[] {
90 TokenTypes.VARIABLE_DEF,
91 TokenTypes.PARAMETER_DEF,
92 TokenTypes.RESOURCE,
93 };
94 }
95
96 @Override
97 public int[] getRequiredTokens() {
98 return CommonUtil.EMPTY_INT_ARRAY;
99 }
100
101 @Override
102 protected final boolean mustCheckName(DetailAST ast) {
103 final DetailAST modifiersAST =
104 ast.findFirstToken(TokenTypes.MODIFIERS);
105 final boolean isFinal = ast.getType() == TokenTypes.RESOURCE
106 || modifiersAST.findFirstToken(TokenTypes.FINAL) != null;
107 return isFinal && ScopeUtil.isLocalVariableDef(ast);
108 }
109
110 }