001//////////////////////////////////////////////////////////////////////////////// 002// checkstyle: Checks Java source code for adherence to a set of rules. 003// Copyright (C) 2001-2022 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.coding; 021 022import java.util.HashMap; 023import java.util.Map; 024 025import com.puppycrawl.tools.checkstyle.StatelessCheck; 026import com.puppycrawl.tools.checkstyle.api.AbstractCheck; 027import com.puppycrawl.tools.checkstyle.api.DetailAST; 028import com.puppycrawl.tools.checkstyle.api.TokenTypes; 029import com.puppycrawl.tools.checkstyle.utils.TokenUtil; 030 031/** 032 * <p> 033 * Checks that overloaded methods are grouped together. Overloaded methods have the same 034 * name but different signatures where the signature can differ by the number of 035 * input parameters or type of input parameters or both. 036 * </p> 037 * <p> 038 * To configure the check: 039 * </p> 040 * <pre> 041 * <module name="OverloadMethodsDeclarationOrder"/> 042 * </pre> 043 * <p> 044 * Example of correct grouping of overloaded methods: 045 * </p> 046 * <pre> 047 * public void foo(int i) {} 048 * public void foo(String s) {} 049 * public void foo(String s, int i) {} 050 * public void foo(int i, String s) {} 051 * public void notFoo() {} 052 * </pre> 053 * <p> 054 * Example of incorrect grouping of overloaded methods: 055 * </p> 056 * <pre> 057 * public void foo(int i) {} // OK 058 * public void foo(String s) {} // OK 059 * public void notFoo() {} // violation. Have to be after foo(String s, int i) 060 * public void foo(int i, String s) {} 061 * public void foo(String s, int i) {} 062 * </pre> 063 * <p> 064 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker} 065 * </p> 066 * <p> 067 * Violation Message Keys: 068 * </p> 069 * <ul> 070 * <li> 071 * {@code overload.methods.declaration} 072 * </li> 073 * </ul> 074 * 075 * @since 5.8 076 */ 077@StatelessCheck 078public class OverloadMethodsDeclarationOrderCheck extends AbstractCheck { 079 080 /** 081 * A key is pointing to the warning message text in "messages.properties" 082 * file. 083 */ 084 public static final String MSG_KEY = "overload.methods.declaration"; 085 086 @Override 087 public int[] getDefaultTokens() { 088 return getRequiredTokens(); 089 } 090 091 @Override 092 public int[] getAcceptableTokens() { 093 return getRequiredTokens(); 094 } 095 096 @Override 097 public int[] getRequiredTokens() { 098 return new int[] { 099 TokenTypes.OBJBLOCK, 100 }; 101 } 102 103 @Override 104 public void visitToken(DetailAST ast) { 105 final int parentType = ast.getParent().getType(); 106 107 final int[] tokenTypes = { 108 TokenTypes.CLASS_DEF, 109 TokenTypes.ENUM_DEF, 110 TokenTypes.INTERFACE_DEF, 111 TokenTypes.LITERAL_NEW, 112 TokenTypes.RECORD_DEF, 113 }; 114 115 if (TokenUtil.isOfType(parentType, tokenTypes)) { 116 checkOverloadMethodsGrouping(ast); 117 } 118 } 119 120 /** 121 * Checks that if overload methods are grouped together they should not be 122 * separated from each other. 123 * 124 * @param objectBlock 125 * is a class, interface or enum object block. 126 */ 127 private void checkOverloadMethodsGrouping(DetailAST objectBlock) { 128 final int allowedDistance = 1; 129 DetailAST currentToken = objectBlock.getFirstChild(); 130 final Map<String, Integer> methodIndexMap = new HashMap<>(); 131 final Map<String, Integer> methodLineNumberMap = new HashMap<>(); 132 int currentIndex = 0; 133 while (currentToken != null) { 134 if (currentToken.getType() == TokenTypes.METHOD_DEF) { 135 currentIndex++; 136 final String methodName = 137 currentToken.findFirstToken(TokenTypes.IDENT).getText(); 138 final Integer previousIndex = methodIndexMap.get(methodName); 139 if (previousIndex != null && currentIndex - previousIndex > allowedDistance) { 140 final int previousLineWithOverloadMethod = 141 methodLineNumberMap.get(methodName); 142 log(currentToken, MSG_KEY, 143 previousLineWithOverloadMethod); 144 } 145 methodIndexMap.put(methodName, currentIndex); 146 methodLineNumberMap.put(methodName, currentToken.getLineNo()); 147 } 148 currentToken = currentToken.getNextSibling(); 149 } 150 } 151 152}