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