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.header;
21
22 import java.io.File;
23 import java.util.BitSet;
24
25 import com.puppycrawl.tools.checkstyle.StatelessCheck;
26 import com.puppycrawl.tools.checkstyle.api.FileText;
27 import com.puppycrawl.tools.checkstyle.utils.TokenUtil;
28
29 /**
30 * <div>
31 * Checks that a source file begins with a specified header.
32 * Property {@code headerFile} specifies a file that contains the required header.
33 * Alternatively, the header specification can be set directly in the
34 * {@code header} property without the need for an external file.
35 * </div>
36 *
37 * <p>
38 * Property {@code ignoreLines} specifies the line numbers to ignore when matching
39 * lines in a header file. This property is very useful for supporting headers
40 * that contain copyright dates. For example, consider the following header:
41 * </p>
42 * <pre>
43 * line 1: ////////////////////////////////////////////////////////////////////
44 * line 2: // checkstyle:
45 * line 3: // Checks Java source code for adherence to a set of rules.
46 * line 4: // Copyright (C) 2002 Oliver Burn
47 * line 5: ////////////////////////////////////////////////////////////////////
48 * </pre>
49 *
50 * <p>
51 * Since the year information will change over time, you can tell Checkstyle
52 * to ignore line 4 by setting property {@code ignoreLines} to {@code 4}.
53 * </p>
54 *
55 * <p>
56 * In default configuration, if header is not specified, the default value
57 * of header is set to {@code null} and the check does not rise any violations.
58 * </p>
59 * <ul>
60 * <li>
61 * Property {@code charset} - Specify the character encoding to use when reading the headerFile.
62 * Type is {@code java.lang.String}.
63 * Default value is {@code the charset property of the parent
64 * <a href="https://checkstyle.org/config.html#Checker">Checker</a> module}.
65 * </li>
66 * <li>
67 * Property {@code fileExtensions} - Specify the file extensions of the files to process.
68 * Type is {@code java.lang.String[]}.
69 * Default value is {@code ""}.
70 * </li>
71 * <li>
72 * Property {@code header} - Specify the required header specified inline.
73 * Individual header lines must be separated by the string {@code "\n"}
74 * (even on platforms with a different line separator).
75 * Type is {@code java.lang.String}.
76 * Default value is {@code null}.
77 * </li>
78 * <li>
79 * Property {@code headerFile} - Specify the name of the file containing the required header.
80 * Type is {@code java.net.URI}.
81 * Default value is {@code null}.
82 * </li>
83 * <li>
84 * Property {@code ignoreLines} - Specify the line numbers to ignore.
85 * Type is {@code int[]}.
86 * Default value is {@code ""}.
87 * </li>
88 * </ul>
89 *
90 * <p>
91 * Parent is {@code com.puppycrawl.tools.checkstyle.Checker}
92 * </p>
93 *
94 * <p>
95 * Violation Message Keys:
96 * </p>
97 * <ul>
98 * <li>
99 * {@code header.mismatch}
100 * </li>
101 * <li>
102 * {@code header.missing}
103 * </li>
104 * </ul>
105 *
106 * @since 6.9
107 */
108 @StatelessCheck
109 public class HeaderCheck extends AbstractHeaderCheck {
110
111 /**
112 * A key is pointing to the warning message text in "messages.properties"
113 * file.
114 */
115 public static final String MSG_MISSING = "header.missing";
116
117 /**
118 * A key is pointing to the warning message text in "messages.properties"
119 * file.
120 */
121 public static final String MSG_MISMATCH = "header.mismatch";
122
123 /** Specify the line numbers to ignore. */
124 private BitSet ignoreLines = new BitSet();
125
126 /**
127 * Returns true if lineNo is header lines or false.
128 *
129 * @param lineNo a line number
130 * @return if {@code lineNo} is one of the ignored header lines.
131 */
132 private boolean isIgnoreLine(int lineNo) {
133 return ignoreLines.get(lineNo);
134 }
135
136 /**
137 * Checks if a code line matches the required header line.
138 *
139 * @param lineNumber the line number to check against the header
140 * @param line the line contents
141 * @return true if and only if the line matches the required header line
142 */
143 private boolean isMatch(int lineNumber, String line) {
144 // skip lines we are meant to ignore
145 return isIgnoreLine(lineNumber + 1)
146 || getHeaderLines().get(lineNumber).equals(line);
147 }
148
149 /**
150 * Setter to specify the line numbers to ignore.
151 *
152 * @param lines line numbers to ignore in header.
153 * @since 3.2
154 */
155 public void setIgnoreLines(int... lines) {
156 ignoreLines = TokenUtil.asBitSet(lines);
157 }
158
159 @Override
160 protected void processFiltered(File file, FileText fileText) {
161 if (getHeaderLines().size() > fileText.size()) {
162 log(1, MSG_MISSING);
163 }
164 else {
165 for (int i = 0; i < getHeaderLines().size(); i++) {
166 if (!isMatch(i, fileText.get(i))) {
167 log(i + 1, MSG_MISMATCH, getHeaderLines().get(i));
168 break;
169 }
170 }
171 }
172 }
173
174 @Override
175 protected void postProcessHeaderLines() {
176 // no code
177 }
178
179 }