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 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#CatchParameterName"> 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#LambdaParameterName"> 045 * LambdaParameterName</a>. 046 * </p> 047 * <ul> 048 * <li> 049 * Property {@code accessModifiers} - Access modifiers of methods where parameters are 050 * checked. 051 * Type is {@code com.puppycrawl.tools.checkstyle.checks.naming.AccessModifierOption[]}. 052 * Default value is {@code public, protected, package, private}. 053 * </li> 054 * <li> 055 * Property {@code format} - Sets the pattern to match valid identifiers. 056 * Type is {@code java.util.regex.Pattern}. 057 * Default value is {@code "^[a-z][a-zA-Z0-9]*$"}. 058 * </li> 059 * <li> 060 * Property {@code ignoreOverridden} - Allows to skip methods with Override annotation from 061 * validation. 062 * Type is {@code boolean}. 063 * Default value is {@code false}. 064 * </li> 065 * </ul> 066 * 067 * <p> 068 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker} 069 * </p> 070 * 071 * <p> 072 * Violation Message Keys: 073 * </p> 074 * <ul> 075 * <li> 076 * {@code name.invalidPattern} 077 * </li> 078 * </ul> 079 * 080 * @since 3.0 081 */ 082public class ParameterNameCheck extends AbstractNameCheck { 083 084 /** 085 * Allows to skip methods with Override annotation from validation. 086 */ 087 private boolean ignoreOverridden; 088 089 /** Access modifiers of methods where parameters are checked. */ 090 private AccessModifierOption[] accessModifiers = { 091 AccessModifierOption.PUBLIC, 092 AccessModifierOption.PROTECTED, 093 AccessModifierOption.PACKAGE, 094 AccessModifierOption.PRIVATE, 095 }; 096 097 /** 098 * Creates a new {@code ParameterNameCheck} instance. 099 */ 100 public ParameterNameCheck() { 101 super("^[a-z][a-zA-Z0-9]*$"); 102 } 103 104 /** 105 * Setter to allows to skip methods with Override annotation from validation. 106 * 107 * @param ignoreOverridden Flag for skipping methods with Override annotation. 108 * @since 6.12.1 109 */ 110 public void setIgnoreOverridden(boolean ignoreOverridden) { 111 this.ignoreOverridden = ignoreOverridden; 112 } 113 114 /** 115 * Setter to access modifiers of methods where parameters are checked. 116 * 117 * @param accessModifiers access modifiers of methods which should be checked. 118 * @since 7.5 119 */ 120 public void setAccessModifiers(AccessModifierOption... accessModifiers) { 121 this.accessModifiers = 122 Arrays.copyOf(accessModifiers, accessModifiers.length); 123 } 124 125 @Override 126 public int[] getDefaultTokens() { 127 return getRequiredTokens(); 128 } 129 130 @Override 131 public int[] getAcceptableTokens() { 132 return getRequiredTokens(); 133 } 134 135 @Override 136 public int[] getRequiredTokens() { 137 return new int[] {TokenTypes.PARAMETER_DEF}; 138 } 139 140 @Override 141 protected boolean mustCheckName(DetailAST ast) { 142 boolean checkName = true; 143 final DetailAST parent = ast.getParent(); 144 if (ignoreOverridden && isOverriddenMethod(ast) 145 || parent.getType() == TokenTypes.LITERAL_CATCH 146 || parent.getParent().getType() == TokenTypes.LAMBDA 147 || CheckUtil.isReceiverParameter(ast) 148 || !matchAccessModifiers( 149 CheckUtil.getAccessModifierFromModifiersToken(parent.getParent()))) { 150 checkName = false; 151 } 152 return checkName; 153 } 154 155 /** 156 * Checks whether a method has the correct access modifier to be checked. 157 * 158 * @param accessModifier the access modifier of the method. 159 * @return whether the method matches the expected access modifier. 160 */ 161 private boolean matchAccessModifiers(final AccessModifierOption accessModifier) { 162 return Arrays.stream(accessModifiers) 163 .anyMatch(modifier -> modifier == accessModifier); 164 } 165 166 /** 167 * Checks whether a method is annotated with Override annotation. 168 * 169 * @param ast method parameter definition token. 170 * @return true if a method is annotated with Override annotation. 171 */ 172 private static boolean isOverriddenMethod(DetailAST ast) { 173 boolean overridden = false; 174 175 final DetailAST parent = ast.getParent().getParent(); 176 final Optional<DetailAST> annotation = 177 Optional.ofNullable(parent.getFirstChild().getFirstChild()); 178 179 if (annotation.isPresent()) { 180 final Optional<DetailAST> overrideToken = 181 Optional.ofNullable(annotation.orElseThrow().findFirstToken(TokenTypes.IDENT)); 182 if (overrideToken.isPresent() 183 && "Override".equals(overrideToken.orElseThrow().getText())) { 184 overridden = true; 185 } 186 } 187 return overridden; 188 } 189 190}