001/////////////////////////////////////////////////////////////////////////////////////////////// 002// checkstyle: Checks Java source code and other text files for adherence to a set of rules. 003// Copyright (C) 2001-2026 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 java.util.Arrays; 023import java.util.Optional; 024 025import com.puppycrawl.tools.checkstyle.api.DetailAST; 026import com.puppycrawl.tools.checkstyle.api.TokenTypes; 027import com.puppycrawl.tools.checkstyle.utils.CheckUtil; 028 029/** 030 * <div> 031 * Checks that method parameter names conform to a specified pattern. 032 * By using {@code accessModifiers} property it is possible 033 * to specify different formats for methods at different visibility levels. 034 * </div> 035 * 036 * <p> 037 * To validate {@code catch} parameters please use 038 * <a href="https://checkstyle.org/checks/naming/catchparametername.html"> 039 * CatchParameterName</a>. 040 * </p> 041 * 042 * <p> 043 * To validate lambda parameters please use 044 * <a href="https://checkstyle.org/checks/naming/lambdaparametername.html"> 045 * LambdaParameterName</a>. 046 * </p> 047 * 048 * @since 3.0 049 */ 050public class ParameterNameCheck extends AbstractNameCheck { 051 052 /** 053 * A key is pointing to the warning message text in "messages.properties" file. 054 */ 055 public static final String MSG_INVALID_PATTERN = "name.invalidPattern"; 056 057 /** 058 * Allows to skip methods with Override annotation from validation. 059 */ 060 private boolean ignoreOverridden; 061 062 /** Access modifiers of methods where parameters are checked. */ 063 private AccessModifierOption[] accessModifiers = { 064 AccessModifierOption.PUBLIC, 065 AccessModifierOption.PROTECTED, 066 AccessModifierOption.PACKAGE, 067 AccessModifierOption.PRIVATE, 068 }; 069 070 /** 071 * Creates a new {@code ParameterNameCheck} instance. 072 */ 073 public ParameterNameCheck() { 074 super("^[a-z][a-zA-Z0-9]*$", MSG_INVALID_PATTERN); 075 } 076 077 /** 078 * Setter to allows to skip methods with Override annotation from validation. 079 * 080 * @param ignoreOverridden Flag for skipping methods with Override annotation. 081 * @since 6.12.1 082 */ 083 public void setIgnoreOverridden(boolean ignoreOverridden) { 084 this.ignoreOverridden = ignoreOverridden; 085 } 086 087 /** 088 * Setter to access modifiers of methods where parameters are checked. 089 * 090 * @param accessModifiers access modifiers of methods which should be checked. 091 * @since 7.5 092 */ 093 public void setAccessModifiers(AccessModifierOption... accessModifiers) { 094 this.accessModifiers = 095 Arrays.copyOf(accessModifiers, accessModifiers.length); 096 } 097 098 @Override 099 public int[] getDefaultTokens() { 100 return getRequiredTokens(); 101 } 102 103 @Override 104 public int[] getAcceptableTokens() { 105 return getRequiredTokens(); 106 } 107 108 @Override 109 public int[] getRequiredTokens() { 110 return new int[] {TokenTypes.PARAMETER_DEF}; 111 } 112 113 @Override 114 protected boolean mustCheckName(DetailAST ast) { 115 boolean checkName = true; 116 final DetailAST parent = ast.getParent(); 117 if (ignoreOverridden && isOverriddenMethod(ast) 118 || parent.getType() == TokenTypes.LITERAL_CATCH 119 || parent.getParent().getType() == TokenTypes.LAMBDA 120 || CheckUtil.isReceiverParameter(ast) 121 || !matchAccessModifiers( 122 CheckUtil.getAccessModifierFromModifiersToken(parent.getParent()))) { 123 checkName = false; 124 } 125 return checkName; 126 } 127 128 /** 129 * Checks whether a method has the correct access modifier to be checked. 130 * 131 * @param accessModifier the access modifier of the method. 132 * @return whether the method matches the expected access modifier. 133 */ 134 private boolean matchAccessModifiers(final AccessModifierOption accessModifier) { 135 return Arrays.stream(accessModifiers) 136 .anyMatch(modifier -> modifier == accessModifier); 137 } 138 139 /** 140 * Checks whether a method is annotated with Override annotation. 141 * 142 * @param ast method parameter definition token. 143 * @return true if a method is annotated with Override annotation. 144 */ 145 private static boolean isOverriddenMethod(DetailAST ast) { 146 boolean overridden = false; 147 148 final DetailAST parent = ast.getParent().getParent(); 149 final Optional<DetailAST> annotation = 150 Optional.ofNullable(parent.getFirstChild().getFirstChild()); 151 152 if (annotation.isPresent()) { 153 final Optional<DetailAST> overrideToken = 154 Optional.ofNullable(annotation.orElseThrow().findFirstToken(TokenTypes.IDENT)); 155 if (overrideToken.isPresent() 156 && "Override".equals(overrideToken.orElseThrow().getText())) { 157 overridden = true; 158 } 159 } 160 return overridden; 161 } 162 163}