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.sizes; 021 022import com.puppycrawl.tools.checkstyle.StatelessCheck; 023import com.puppycrawl.tools.checkstyle.api.AbstractCheck; 024import com.puppycrawl.tools.checkstyle.api.DetailAST; 025import com.puppycrawl.tools.checkstyle.api.TokenTypes; 026import com.puppycrawl.tools.checkstyle.utils.AnnotationUtil; 027import com.puppycrawl.tools.checkstyle.utils.CommonUtil; 028 029/** 030 * <p> 031 * Checks the number of parameters of a method or constructor. 032 * </p> 033 * <ul> 034 * <li> 035 * Property {@code ignoreOverriddenMethods} - Ignore number of parameters for 036 * methods with {@code @Override} annotation. 037 * Type is {@code boolean}. 038 * Default value is {@code false}. 039 * </li> 040 * <li> 041 * Property {@code max} - Specify the maximum number of parameters allowed. 042 * Type is {@code int}. 043 * Default value is {@code 7}. 044 * </li> 045 * <li> 046 * Property {@code tokens} - tokens to check 047 * Type is {@code java.lang.String[]}. 048 * Validation type is {@code tokenSet}. 049 * Default value is: 050 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#METHOD_DEF"> 051 * METHOD_DEF</a>, 052 * <a href="https://checkstyle.org/apidocs/com/puppycrawl/tools/checkstyle/api/TokenTypes.html#CTOR_DEF"> 053 * CTOR_DEF</a>. 054 * </li> 055 * </ul> 056 * <p> 057 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker} 058 * </p> 059 * <p> 060 * Violation Message Keys: 061 * </p> 062 * <ul> 063 * <li> 064 * {@code maxParam} 065 * </li> 066 * </ul> 067 * 068 * @since 3.0 069 */ 070@StatelessCheck 071public class ParameterNumberCheck 072 extends AbstractCheck { 073 074 /** 075 * A key is pointing to the warning message text in "messages.properties" 076 * file. 077 */ 078 public static final String MSG_KEY = "maxParam"; 079 080 /** Default maximum number of allowed parameters. */ 081 private static final int DEFAULT_MAX_PARAMETERS = 7; 082 083 /** Specify the maximum number of parameters allowed. */ 084 private int max = DEFAULT_MAX_PARAMETERS; 085 086 /** Ignore number of parameters for methods with {@code @Override} annotation. */ 087 private boolean ignoreOverriddenMethods; 088 089 /** 090 * Setter to specify the maximum number of parameters allowed. 091 * 092 * @param max the max allowed parameters 093 * @since 3.0 094 */ 095 public void setMax(int max) { 096 this.max = max; 097 } 098 099 /** 100 * Setter to ignore number of parameters for methods with {@code @Override} annotation. 101 * 102 * @param ignoreOverriddenMethods set ignore overridden methods 103 * @since 6.2 104 */ 105 public void setIgnoreOverriddenMethods(boolean ignoreOverriddenMethods) { 106 this.ignoreOverriddenMethods = ignoreOverriddenMethods; 107 } 108 109 @Override 110 public int[] getDefaultTokens() { 111 return getAcceptableTokens(); 112 } 113 114 @Override 115 public int[] getAcceptableTokens() { 116 return new int[] {TokenTypes.METHOD_DEF, TokenTypes.CTOR_DEF}; 117 } 118 119 @Override 120 public int[] getRequiredTokens() { 121 return CommonUtil.EMPTY_INT_ARRAY; 122 } 123 124 @Override 125 public void visitToken(DetailAST ast) { 126 final DetailAST params = ast.findFirstToken(TokenTypes.PARAMETERS); 127 final int count = params.getChildCount(TokenTypes.PARAMETER_DEF); 128 if (count > max && !shouldIgnoreNumberOfParameters(ast)) { 129 final DetailAST name = ast.findFirstToken(TokenTypes.IDENT); 130 log(name, MSG_KEY, max, count); 131 } 132 } 133 134 /** 135 * Determine whether to ignore number of parameters for the method. 136 * 137 * @param ast the token to process 138 * @return true if this is overridden method and number of parameters should be ignored 139 * false otherwise 140 */ 141 private boolean shouldIgnoreNumberOfParameters(DetailAST ast) { 142 // if you override a method, you have no power over the number of parameters 143 return ignoreOverriddenMethods 144 && AnnotationUtil.hasOverrideAnnotation(ast); 145 } 146 147}