001///////////////////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code and other text files for adherence to a set of rules.
003// Copyright (C) 2001-2024 the original author or authors.
004//
005// This library is free software; you can redistribute it and/or
006// modify it under the terms of the GNU Lesser General Public
007// License as published by the Free Software Foundation; either
008// version 2.1 of the License, or (at your option) any later version.
009//
010// This library is distributed in the hope that it will be useful,
011// but WITHOUT ANY WARRANTY; without even the implied warranty of
012// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
013// Lesser General Public License for more details.
014//
015// You should have received a copy of the GNU Lesser General Public
016// License along with this library; if not, write to the Free Software
017// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
018///////////////////////////////////////////////////////////////////////////////////////////////
019
020package com.puppycrawl.tools.checkstyle.checks.naming;
021
022import com.puppycrawl.tools.checkstyle.api.DetailAST;
023import com.puppycrawl.tools.checkstyle.api.TokenTypes;
024import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
025import com.puppycrawl.tools.checkstyle.utils.ScopeUtil;
026
027/**
028 * <div>
029 * Checks that local final variable names conform to a specified pattern.
030 *  A catch parameter and resources in try statements
031 * are considered to be a local, final variables.
032 * </div>
033 *
034 * <p>
035 * This check does not support final pattern variables. Instead, use
036 * <a href="https://checkstyle.org/checks/naming/patternvariablename.html#PatternVariableName">
037 * PatternVariableName</a>.
038 * </p>
039 * <ul>
040 * <li>
041 * Property {@code format} - Sets the pattern to match valid identifiers.
042 * Type is {@code java.util.regex.Pattern}.
043 * Default value is {@code "^([a-z][a-zA-Z0-9]*|_)$"}.
044 * </li>
045 * <li>
046 * Property {@code tokens} - tokens to check
047 * Type is {@code java.lang.String[]}.
048 * Validation type is {@code tokenSet}.
049 * Default value is:
050 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#VARIABLE_DEF">
051 * VARIABLE_DEF</a>,
052 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#PARAMETER_DEF">
053 * PARAMETER_DEF</a>,
054 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#RESOURCE">
055 * RESOURCE</a>.
056 * </li>
057 * </ul>
058 *
059 * <p>
060 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
061 * </p>
062 *
063 * <p>
064 * Violation Message Keys:
065 * </p>
066 * <ul>
067 * <li>
068 * {@code name.invalidPattern}
069 * </li>
070 * </ul>
071 *
072 * @since 3.0
073 */
074public class LocalFinalVariableNameCheck
075    extends AbstractNameCheck {
076
077    /** Creates a new {@code LocalFinalVariableNameCheck} instance. */
078    public LocalFinalVariableNameCheck() {
079        super("^([a-z][a-zA-Z0-9]*|_)$");
080    }
081
082    @Override
083    public int[] getDefaultTokens() {
084        return getAcceptableTokens();
085    }
086
087    @Override
088    public int[] getAcceptableTokens() {
089        return new int[] {
090            TokenTypes.VARIABLE_DEF,
091            TokenTypes.PARAMETER_DEF,
092            TokenTypes.RESOURCE,
093        };
094    }
095
096    @Override
097    public int[] getRequiredTokens() {
098        return CommonUtil.EMPTY_INT_ARRAY;
099    }
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}