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.AnnotationUtil; 025 026/** 027 * <div> 028 * Checks that method names conform to a specified pattern. 029 * </div> 030 * 031 * <p>Also, checks if a method name has the same name as the residing class. 032 * The default is false (it is not allowed). It is legal in Java to have 033 * method with the same name as a class. As long as a return type is specified 034 * it is a method and not a constructor which it could be easily confused as. 035 * Does not check-style the name of an overridden methods because the developer does not 036 * have a choice in renaming such methods. 037 * </p> 038 * 039 * <ul> 040 * <li> 041 * Property {@code allowClassName} - Control whether to allow a method name to have the same name 042 * as the enclosing class name. Setting this property {@code false} helps to avoid 043 * confusion between constructors and methods. 044 * Type is {@code boolean}. 045 * Default value is {@code false}. 046 * </li> 047 * <li> 048 * Property {@code applyToPackage} - Control if check should apply to package-private members. 049 * Type is {@code boolean}. 050 * Default value is {@code true}. 051 * </li> 052 * <li> 053 * Property {@code applyToPrivate} - Control if check should apply to private members. 054 * Type is {@code boolean}. 055 * Default value is {@code true}. 056 * </li> 057 * <li> 058 * Property {@code applyToProtected} - Control if check should apply to protected members. 059 * Type is {@code boolean}. 060 * Default value is {@code true}. 061 * </li> 062 * <li> 063 * Property {@code applyToPublic} - Control if check should apply to public members. 064 * Type is {@code boolean}. 065 * Default value is {@code true}. 066 * </li> 067 * <li> 068 * Property {@code format} - Sets the pattern to match valid identifiers. 069 * Type is {@code java.util.regex.Pattern}. 070 * Default value is {@code "^[a-z][a-zA-Z0-9]*$"}. 071 * </li> 072 * </ul> 073 * 074 * <p> 075 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker} 076 * </p> 077 * 078 * <p> 079 * Violation Message Keys: 080 * </p> 081 * <ul> 082 * <li> 083 * {@code method.name.equals.class.name} 084 * </li> 085 * <li> 086 * {@code name.invalidPattern} 087 * </li> 088 * </ul> 089 * 090 * @since 3.0 091 */ 092public class MethodNameCheck 093 extends AbstractAccessControlNameCheck { 094 095 /** 096 * A key is pointing to the warning message text in "messages.properties" 097 * file. 098 */ 099 public static final String MSG_KEY = "method.name.equals.class.name"; 100 101 /** 102 * Control whether to allow a method name to have the same name as the enclosing class name. 103 * Setting this property {@code false} helps to avoid confusion 104 * between constructors and methods. 105 */ 106 private boolean allowClassName; 107 108 /** Creates a new {@code MethodNameCheck} instance. */ 109 public MethodNameCheck() { 110 super("^[a-z][a-zA-Z0-9]*$"); 111 } 112 113 @Override 114 public int[] getDefaultTokens() { 115 return getRequiredTokens(); 116 } 117 118 @Override 119 public int[] getAcceptableTokens() { 120 return getRequiredTokens(); 121 } 122 123 @Override 124 public int[] getRequiredTokens() { 125 return new int[] {TokenTypes.METHOD_DEF, }; 126 } 127 128 @Override 129 public void visitToken(DetailAST ast) { 130 if (!AnnotationUtil.hasOverrideAnnotation(ast)) { 131 // Will check the name against the format. 132 super.visitToken(ast); 133 } 134 135 if (!allowClassName) { 136 final DetailAST method = 137 ast.findFirstToken(TokenTypes.IDENT); 138 // in all cases this will be the classDef type except anon inner 139 // with anon inner classes this will be the Literal_New keyword 140 final DetailAST classDefOrNew = ast.getParent().getParent(); 141 final DetailAST classIdent = 142 classDefOrNew.findFirstToken(TokenTypes.IDENT); 143 // Following logic is to handle when a classIdent can not be 144 // found. This is when you have a Literal_New keyword followed 145 // a DOT, which is when you have: 146 // new Outclass.InnerInterface(x) { ... } 147 // Such a rare case, will not have the logic to handle parsing 148 // down the tree looking for the first ident. 149 if (classIdent != null 150 && method.getText().equals(classIdent.getText())) { 151 log(method, MSG_KEY, method.getText()); 152 } 153 } 154 } 155 156 /** 157 * Setter to control whether to allow a method name to have the same name 158 * as the enclosing class name. Setting this property {@code false} 159 * helps to avoid confusion between constructors and methods. 160 * 161 * @param allowClassName true to allow false to disallow 162 * @since 5.0 163 */ 164 public void setAllowClassName(boolean allowClassName) { 165 this.allowClassName = allowClassName; 166 } 167 168}