001//////////////////////////////////////////////////////////////////////////////// 002// checkstyle: Checks Java source code for adherence to a set of rules. 003// Copyright (C) 2001-2017 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.api.AbstractCheck; 023import com.puppycrawl.tools.checkstyle.api.DetailAST; 024import com.puppycrawl.tools.checkstyle.api.TokenTypes; 025import com.puppycrawl.tools.checkstyle.utils.CommonUtils; 026 027/** 028 * <p>Checks that long constants are defined with an upper ell. 029 * That is <span class="code">'L'</span> and not 030 * <span class="code">'l'</span>. This is in accordance to the Java Language 031 * Specification, <a href="http://docs.oracle.com/javase/specs/jls/se8/html/jls-3.html#jls-3.10.1"> 032 * Section 3.10.1</a>. 033 * </p> 034 * <p> 035 * Rationale: The letter <span class="code">l</span> looks a lot 036 * like the number <span class="code">1</span>. 037 * </p> 038 * 039 * <p>Examples 040 * <p class="body"> 041 * To configure the check: 042 * 043 * </p> 044 * <pre class="body"> 045 * <module name="UpperEll"/> 046 * </pre> 047 * 048 * @author Oliver Burn 049 */ 050public class UpperEllCheck extends AbstractCheck { 051 052 /** 053 * A key is pointing to the warning message text in "messages.properties" 054 * file. 055 */ 056 public static final String MSG_KEY = "upperEll"; 057 058 @Override 059 public int[] getDefaultTokens() { 060 return getAcceptableTokens(); 061 } 062 063 @Override 064 public int[] getAcceptableTokens() { 065 return new int[] {TokenTypes.NUM_LONG}; 066 } 067 068 @Override 069 public int[] getRequiredTokens() { 070 return getAcceptableTokens(); 071 } 072 073 @Override 074 public void visitToken(DetailAST ast) { 075 if (CommonUtils.endsWithChar(ast.getText(), 'l')) { 076 log(ast.getLineNo(), 077 ast.getColumnNo() + ast.getText().length() - 1, 078 MSG_KEY); 079 } 080 } 081}