001//////////////////////////////////////////////////////////////////////////////// 002// checkstyle: Checks Java source code for adherence to a set of rules. 003// Copyright (C) 2001-2014 Oliver Burn 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//////////////////////////////////////////////////////////////////////////////// 019package com.puppycrawl.tools.checkstyle.checks.naming; 020 021import java.util.regex.Pattern; 022 023import com.puppycrawl.tools.checkstyle.api.DetailAST; 024import com.puppycrawl.tools.checkstyle.api.ScopeUtils; 025import com.puppycrawl.tools.checkstyle.api.TokenTypes; 026import com.puppycrawl.tools.checkstyle.api.Utils; 027 028/** 029 * <p> 030 * Checks that local, non-final variable names conform to a format specified 031 * by the format property. A catch parameter is considered to be 032 * a local variable. The format is a 033 * {@link java.util.regex.Pattern regular expression} 034 * and defaults to 035 * <strong>^[a-z][a-zA-Z0-9]*$</strong>. 036 * </p> 037 * <p> 038 * An example of how to configure the check is: 039 * </p> 040 * <pre> 041 * <module name="LocalVariableName"/> 042 * </pre> 043 * <p> 044 * An example of how to configure the check for names that begin with a lower 045 * case letter, followed by letters, digits, and underscores is: 046 * </p> 047 * <pre> 048 * <module name="LocalVariableName"> 049 * <property name="format" value="^[a-z](_?[a-zA-Z0-9]+)*$"/> 050 * </module> 051 * </pre> 052 * <p> 053 * An example of one character variable name in 054 * initialization expression(like "i") in FOR loop: 055 * </p> 056 * <pre> 057 * for(int i = 1; i < 10; i++) {} 058 * </pre> 059 * <p> 060 * An example of how to configure the check to allow one char variable name in 061 * <a href="http://docs.oracle.com/javase/tutorial/java/nutsandbolts/for.html"> 062 * initialization expressions</a> in FOR loop: 063 * </p> 064 * <pre> 065 * <module name="LocalVariableName"> 066 * <property name="allowOneCharVarInForLoop" value="true"/> 067 * </module> 068 * </pre> 069 * <p> 070 * 071 * @author Rick Giles 072 * @author maxvetrenko 073 * @version 1.0 074 */ 075public class LocalVariableNameCheck 076 extends AbstractNameCheck 077{ 078 /** 079 * Allow one character name for initialization expression in FOR loop. 080 */ 081 private boolean allowOneCharVarInForLoop; 082 083 /** Regexp for one-char loop variables. */ 084 private static Pattern sSingleChar = Utils.getPattern("^[a-z]$"); 085 086 /** Creates a new <code>LocalVariableNameCheck</code> instance. */ 087 public LocalVariableNameCheck() 088 { 089 super("^[a-z][a-zA-Z0-9]*$"); 090 } 091 092 public final void setAllowOneCharVarInForLoop(boolean allow) 093 { 094 allowOneCharVarInForLoop = allow; 095 } 096 097 @Override 098 public int[] getDefaultTokens() 099 { 100 return new int[] { 101 TokenTypes.VARIABLE_DEF, 102 TokenTypes.PARAMETER_DEF, 103 }; 104 } 105 106 @Override 107 protected final boolean mustCheckName(DetailAST ast) 108 { 109 final DetailAST modifiersAST = 110 ast.findFirstToken(TokenTypes.MODIFIERS); 111 final boolean isFinal = (modifiersAST != null) 112 && modifiersAST.branchContains(TokenTypes.FINAL); 113 if (allowOneCharVarInForLoop && isForLoopVariable(ast)) { 114 final String variableName = 115 ast.findFirstToken(TokenTypes.IDENT).getText(); 116 return !sSingleChar.matcher(variableName).find(); 117 } 118 return (!isFinal && ScopeUtils.isLocalVariableDef(ast)); 119 } 120 121 /** 122 * Checks if a variable is the loop's one. 123 * @param variableDef variable definition. 124 * @return true if a variable is the loop's one. 125 */ 126 private boolean isForLoopVariable(DetailAST variableDef) 127 { 128 final int parentType = variableDef.getParent().getType(); 129 return parentType == TokenTypes.FOR_INIT 130 || parentType == TokenTypes.FOR_EACH_CLAUSE; 131 } 132}