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 * <p> 028 * Checks that method names conform to a specified pattern. 029 * </p> 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]*$"}. 071 * </li> 072 * </ul> 073 * <p> 074 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker} 075 * </p> 076 * <p> 077 * Violation Message Keys: 078 * </p> 079 * <ul> 080 * <li> 081 * {@code method.name.equals.class.name} 082 * </li> 083 * <li> 084 * {@code name.invalidPattern} 085 * </li> 086 * </ul> 087 * 088 * @since 3.0 089 */ 090public class MethodNameCheck 091 extends AbstractAccessControlNameCheck { 092 093 /** 094 * A key is pointing to the warning message text in "messages.properties" 095 * file. 096 */ 097 public static final String MSG_KEY = "method.name.equals.class.name"; 098 099 /** 100 * Control whether to allow a method name to have the same name as the enclosing class name. 101 * Setting this property {@code false} helps to avoid confusion 102 * between constructors and methods. 103 */ 104 private boolean allowClassName; 105 106 /** Creates a new {@code MethodNameCheck} instance. */ 107 public MethodNameCheck() { 108 super("^[a-z][a-zA-Z0-9]*$"); 109 } 110 111 @Override 112 public int[] getDefaultTokens() { 113 return getRequiredTokens(); 114 } 115 116 @Override 117 public int[] getAcceptableTokens() { 118 return getRequiredTokens(); 119 } 120 121 @Override 122 public int[] getRequiredTokens() { 123 return new int[] {TokenTypes.METHOD_DEF, }; 124 } 125 126 @Override 127 public void visitToken(DetailAST ast) { 128 if (!AnnotationUtil.hasOverrideAnnotation(ast)) { 129 // Will check the name against the format. 130 super.visitToken(ast); 131 } 132 133 if (!allowClassName) { 134 final DetailAST method = 135 ast.findFirstToken(TokenTypes.IDENT); 136 // in all cases this will be the classDef type except anon inner 137 // with anon inner classes this will be the Literal_New keyword 138 final DetailAST classDefOrNew = ast.getParent().getParent(); 139 final DetailAST classIdent = 140 classDefOrNew.findFirstToken(TokenTypes.IDENT); 141 // Following logic is to handle when a classIdent can not be 142 // found. This is when you have a Literal_New keyword followed 143 // a DOT, which is when you have: 144 // new Outclass.InnerInterface(x) { ... } 145 // Such a rare case, will not have the logic to handle parsing 146 // down the tree looking for the first ident. 147 if (classIdent != null 148 && method.getText().equals(classIdent.getText())) { 149 log(method, MSG_KEY, method.getText()); 150 } 151 } 152 } 153 154 /** 155 * Setter to control whether to allow a method name to have the same name 156 * as the enclosing class name. Setting this property {@code false} 157 * helps to avoid confusion between constructors and methods. 158 * 159 * @param allowClassName true to allow false to disallow 160 * @since 5.0 161 */ 162 public void setAllowClassName(boolean allowClassName) { 163 this.allowClassName = allowClassName; 164 } 165 166}