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.whitespace; 021 022import java.io.File; 023 024import com.puppycrawl.tools.checkstyle.StatelessCheck; 025import com.puppycrawl.tools.checkstyle.api.AbstractFileSetCheck; 026import com.puppycrawl.tools.checkstyle.api.FileText; 027 028/** 029 * <div> 030 * Checks that there are no tab characters ({@code '\t'}) in the source code. 031 * </div> 032 * 033 * <p> 034 * Rationale: 035 * </p> 036 * <ul> 037 * <li> 038 * Developers should not need to configure the tab width of their text editors in order 039 * to be able to read source code. 040 * </li> 041 * <li> 042 * From the Apache jakarta coding standards: In a distributed development environment, 043 * when the commit messages get sent to a mailing list, they are almost impossible to 044 * read if you use tabs. 045 * </li> 046 * </ul> 047 * <ul> 048 * <li> 049 * Property {@code eachLine} - Control whether to report on each line containing a tab, 050 * or just the first instance. 051 * Type is {@code boolean}. 052 * Default value is {@code false}. 053 * </li> 054 * <li> 055 * Property {@code fileExtensions} - Specify the file extensions of the files to process. 056 * Type is {@code java.lang.String[]}. 057 * Default value is {@code ""}. 058 * </li> 059 * </ul> 060 * 061 * <p> 062 * Parent is {@code com.puppycrawl.tools.checkstyle.Checker} 063 * </p> 064 * 065 * <p> 066 * Violation Message Keys: 067 * </p> 068 * <ul> 069 * <li> 070 * {@code containsTab} 071 * </li> 072 * <li> 073 * {@code file.containsTab} 074 * </li> 075 * </ul> 076 * 077 * @since 5.0 078 */ 079@StatelessCheck 080public class FileTabCharacterCheck extends AbstractFileSetCheck { 081 082 /** 083 * A key is pointing to the warning message text in "messages.properties" 084 * file. 085 */ 086 public static final String MSG_CONTAINS_TAB = "containsTab"; 087 088 /** 089 * A key is pointing to the warning message text in "messages.properties" 090 * file. 091 */ 092 public static final String MSG_FILE_CONTAINS_TAB = "file.containsTab"; 093 094 /** Control whether to report on each line containing a tab, or just the first instance. */ 095 private boolean eachLine; 096 097 @Override 098 protected void processFiltered(File file, FileText fileText) { 099 int lineNum = 0; 100 for (int index = 0; index < fileText.size(); index++) { 101 final String line = fileText.get(index); 102 lineNum++; 103 final int tabPosition = line.indexOf('\t'); 104 if (tabPosition != -1) { 105 if (eachLine) { 106 log(lineNum, tabPosition, MSG_CONTAINS_TAB); 107 } 108 else { 109 log(lineNum, tabPosition, MSG_FILE_CONTAINS_TAB); 110 break; 111 } 112 } 113 } 114 } 115 116 /** 117 * Setter to control whether to report on each line containing a tab, or just the first 118 * instance. 119 * 120 * @param eachLine Whether report on each line containing a tab. 121 * @since 5.0 122 */ 123 public void setEachLine(boolean eachLine) { 124 this.eachLine = eachLine; 125 } 126 127}