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 * <p>
30 * Checks that there are no tab characters ({@code '\t'}) in the source code.
31 * </p>
32 * <p>
33 * Rationale:
34 * </p>
35 * <ul>
36 * <li>
37 * Developers should not need to configure the tab width of their text editors in order
38 * to be able to read source code.
39 * </li>
40 * <li>
41 * From the Apache jakarta coding standards: In a distributed development environment,
42 * when the commit messages get sent to a mailing list, they are almost impossible to
43 * read if you use tabs.
44 * </li>
45 * </ul>
46 * <ul>
47 * <li>
48 * Property {@code eachLine} - Control whether to report on each line containing a tab,
49 * or just the first instance.
50 * Type is {@code boolean}.
51 * Default value is {@code false}.
52 * </li>
53 * <li>
54 * Property {@code fileExtensions} - Specify the file extensions of the files to process.
55 * Type is {@code java.lang.String[]}.
56 * Default value is {@code ""}.
57 * </li>
58 * </ul>
59 * <p>
60 * Parent is {@code com.puppycrawl.tools.checkstyle.Checker}
61 * </p>
62 * <p>
63 * Violation Message Keys:
64 * </p>
65 * <ul>
66 * <li>
67 * {@code containsTab}
68 * </li>
69 * <li>
70 * {@code file.containsTab}
71 * </li>
72 * </ul>
73 *
74 * @since 5.0
75 */
76 @StatelessCheck
77 public class FileTabCharacterCheck extends AbstractFileSetCheck {
78
79 /**
80 * A key is pointing to the warning message text in "messages.properties"
81 * file.
82 */
83 public static final String MSG_CONTAINS_TAB = "containsTab";
84
85 /**
86 * A key is pointing to the warning message text in "messages.properties"
87 * file.
88 */
89 public static final String MSG_FILE_CONTAINS_TAB = "file.containsTab";
90
91 /** Control whether to report on each line containing a tab, or just the first instance. */
92 private boolean eachLine;
93
94 @Override
95 protected void processFiltered(File file, FileText fileText) {
96 int lineNum = 0;
97 for (int index = 0; index < fileText.size(); index++) {
98 final String line = fileText.get(index);
99 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 }