1 ///////////////////////////////////////////////////////////////////////////////////////////////
2 // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
3 // Copyright (C) 2001-2024 the original author or authors.
4 //
5 // This library is free software; you can redistribute it and/or
6 // modify it under the terms of the GNU Lesser General Public
7 // License as published by the Free Software Foundation; either
8 // version 2.1 of the License, or (at your option) any later version.
9 //
10 // This library is distributed in the hope that it will be useful,
11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 // Lesser General Public License for more details.
14 //
15 // You should have received a copy of the GNU Lesser General Public
16 // License along with this library; if not, write to the Free Software
17 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 ///////////////////////////////////////////////////////////////////////////////////////////////
19
20 package com.puppycrawl.tools.checkstyle.checks.whitespace;
21
22 import java.io.File;
23
24 import com.puppycrawl.tools.checkstyle.StatelessCheck;
25 import com.puppycrawl.tools.checkstyle.api.AbstractFileSetCheck;
26 import com.puppycrawl.tools.checkstyle.api.FileText;
27
28 /**
29 * <div>
30 * Checks that there are no tab characters ({@code '\t'}) in the source code.
31 * </div>
32 *
33 * <p>
34 * Rationale:
35 * </p>
36 * <ul>
37 * <li>
38 * Developers should not need to configure the tab width of their text editors in order
39 * to be able to read source code.
40 * </li>
41 * <li>
42 * From the Apache jakarta coding standards: In a distributed development environment,
43 * when the commit messages get sent to a mailing list, they are almost impossible to
44 * read if you use tabs.
45 * </li>
46 * </ul>
47 * <ul>
48 * <li>
49 * Property {@code eachLine} - Control whether to report on each line containing a tab,
50 * or just the first instance.
51 * Type is {@code boolean}.
52 * Default value is {@code false}.
53 * </li>
54 * <li>
55 * Property {@code fileExtensions} - Specify the file extensions of the files to process.
56 * Type is {@code java.lang.String[]}.
57 * Default value is {@code ""}.
58 * </li>
59 * </ul>
60 *
61 * <p>
62 * Parent is {@code com.puppycrawl.tools.checkstyle.Checker}
63 * </p>
64 *
65 * <p>
66 * Violation Message Keys:
67 * </p>
68 * <ul>
69 * <li>
70 * {@code containsTab}
71 * </li>
72 * <li>
73 * {@code file.containsTab}
74 * </li>
75 * </ul>
76 *
77 * @since 5.0
78 */
79 @StatelessCheck
80 public class FileTabCharacterCheck extends AbstractFileSetCheck {
81
82 /**
83 * A key is pointing to the warning message text in "messages.properties"
84 * file.
85 */
86 public static final String MSG_CONTAINS_TAB = "containsTab";
87
88 /**
89 * A key is pointing to the warning message text in "messages.properties"
90 * file.
91 */
92 public static final String MSG_FILE_CONTAINS_TAB = "file.containsTab";
93
94 /** Control whether to report on each line containing a tab, or just the first instance. */
95 private boolean eachLine;
96
97 @Override
98 protected void processFiltered(File file, FileText fileText) {
99 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 }