1 ///////////////////////////////////////////////////////////////////////////////////////////////
2 // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
3 // Copyright (C) 2001-2026 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">
37 * PatternVariableName</a>.
38 * </p>
39 *
40 * @since 3.0
41 */
42 public class LocalFinalVariableNameCheck
43 extends AbstractNameCheck {
44
45 /**
46 * A key is pointing to the warning message text in "messages.properties"
47 * file.
48 */
49 public static final String MSG_INVALID_PATTERN = "name.invalidPattern";
50
51 /** Creates a new {@code LocalFinalVariableNameCheck} instance. */
52 public LocalFinalVariableNameCheck() {
53 super("^([a-z][a-zA-Z0-9]*|_)$", MSG_INVALID_PATTERN);
54 }
55
56 @Override
57 public int[] getDefaultTokens() {
58 return getAcceptableTokens();
59 }
60
61 @Override
62 public int[] getAcceptableTokens() {
63 return new int[] {
64 TokenTypes.VARIABLE_DEF,
65 TokenTypes.PARAMETER_DEF,
66 TokenTypes.RESOURCE,
67 };
68 }
69
70 @Override
71 public int[] getRequiredTokens() {
72 return CommonUtil.EMPTY_INT_ARRAY;
73 }
74
75 @Override
76 protected final boolean mustCheckName(DetailAST ast) {
77 final DetailAST modifiersAST =
78 ast.findFirstToken(TokenTypes.MODIFIERS);
79 final boolean isFinal = ast.getType() == TokenTypes.RESOURCE
80 || modifiersAST.findFirstToken(TokenTypes.FINAL) != null;
81 return isFinal && ScopeUtil.isLocalVariableDef(ast);
82 }
83
84 }