001/////////////////////////////////////////////////////////////////////////////////////////////// 002// checkstyle: Checks Java source code and other text files 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; 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; 026 027/** 028 * <p> 029 * Checks the style of array type definitions. 030 * Some like Java style: {@code public static void main(String[] args)} 031 * and some like C style: {@code public static void main(String args[])}. 032 * </p> 033 * <p> 034 * By default, the Check enforces Java style. 035 * </p> 036 * <p> 037 * This check strictly enforces only Java style for method return types regardless 038 * of the value for 'javaStyle'. For example, {@code byte[] getData()}. 039 * This is because C doesn't compile methods with array declarations on the name. 040 * </p> 041 * <ul> 042 * <li> 043 * Property {@code javaStyle} - Control whether to enforce Java style (true) or C style (false). 044 * Type is {@code boolean}. 045 * Default value is {@code true}. 046 * </li> 047 * </ul> 048 * <p> 049 * To configure the check to enforce Java style: 050 * </p> 051 * <pre> 052 * <module name="ArrayTypeStyle"/> 053 * </pre> 054 * <p> 055 * Example: 056 * </p> 057 * <pre> 058 * public class MyClass { 059 * int[] nums; // OK 060 * String strings[]; // violation 061 * 062 * char[] toCharArray() { // OK 063 * return null; 064 * } 065 * 066 * byte getData()[] { // violation 067 * return null; 068 * } 069 * } 070 * </pre> 071 * <p> 072 * To configure the check to enforce C style: 073 * </p> 074 * <pre> 075 * <module name="ArrayTypeStyle"> 076 * <property name="javaStyle" value="false"/> 077 * </module> 078 * </pre> 079 * <p> 080 * Example: 081 * </p> 082 * <pre> 083 * public class MyClass { 084 * int[] nums; // violation 085 * String strings[]; // OK 086 * 087 * char[] toCharArray() { // OK 088 * return null; 089 * } 090 * 091 * byte getData()[] { // violation 092 * return null; 093 * } 094 * } 095 * </pre> 096 * <p> 097 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker} 098 * </p> 099 * <p> 100 * Violation Message Keys: 101 * </p> 102 * <ul> 103 * <li> 104 * {@code array.type.style} 105 * </li> 106 * </ul> 107 * 108 * @since 3.1 109 */ 110@StatelessCheck 111public class ArrayTypeStyleCheck extends AbstractCheck { 112 113 /** 114 * A key is pointing to the warning message text in "messages.properties" 115 * file. 116 */ 117 public static final String MSG_KEY = "array.type.style"; 118 119 /** Control whether to enforce Java style (true) or C style (false). */ 120 private boolean javaStyle = true; 121 122 @Override 123 public int[] getDefaultTokens() { 124 return getRequiredTokens(); 125 } 126 127 @Override 128 public int[] getAcceptableTokens() { 129 return getRequiredTokens(); 130 } 131 132 @Override 133 public int[] getRequiredTokens() { 134 return new int[] {TokenTypes.ARRAY_DECLARATOR}; 135 } 136 137 @Override 138 public void visitToken(DetailAST ast) { 139 final DetailAST typeAST = ast.getParent(); 140 final DetailAST identAst = typeAST.getNextSibling(); 141 // If identAst is null, we have a 'LITERAL_NEW' expression, i.e. 'new int[2][2]' 142 if (identAst != null) { 143 final boolean isMethod = typeAST.getParent().getType() == TokenTypes.METHOD_DEF; 144 final boolean isJavaStyle = identAst.getLineNo() > ast.getLineNo() 145 || identAst.getColumnNo() - ast.getColumnNo() > -1; 146 147 // force all methods to be Java style (see note in top Javadoc) 148 final boolean isMethodViolation = isMethod && !isJavaStyle; 149 final boolean isVariableViolation = !isMethod 150 && isJavaStyle != javaStyle; 151 152 if (isMethodViolation || isVariableViolation) { 153 log(ast, MSG_KEY); 154 } 155 } 156 } 157 158 /** 159 * Setter to control whether to enforce Java style (true) or C style (false). 160 * 161 * @param javaStyle true if Java style should be used. 162 */ 163 public void setJavaStyle(boolean javaStyle) { 164 this.javaStyle = javaStyle; 165 } 166 167}