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.javadoc;
21
22 import com.puppycrawl.tools.checkstyle.StatelessCheck;
23 import com.puppycrawl.tools.checkstyle.api.DetailNode;
24 import com.puppycrawl.tools.checkstyle.api.JavadocTokenTypes;
25 import com.puppycrawl.tools.checkstyle.utils.JavadocUtil;
26
27 /**
28 * <div>
29 * Checks that there is at least one whitespace after the leading asterisk.
30 * Although spaces after asterisks are optional in the Javadoc comments, their absence
31 * makes the documentation difficult to read. It is the de facto standard to put at least
32 * one whitespace after the leading asterisk.
33 * </div>
34 * <ul>
35 * <li>
36 * Property {@code violateExecutionOnNonTightHtml} - Control when to print violations
37 * if the Javadoc being examined by this check violates the tight html rules defined at
38 * <a href="https://checkstyle.org/writingjavadocchecks.html#Tight-HTML_rules">Tight-HTML Rules</a>.
39 * Type is {@code boolean}.
40 * Default value is {@code false}.
41 * </li>
42 * </ul>
43 *
44 * <p>
45 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
46 * </p>
47 *
48 * <p>
49 * Violation Message Keys:
50 * </p>
51 * <ul>
52 * <li>
53 * {@code javadoc.missed.html.close}
54 * </li>
55 * <li>
56 * {@code javadoc.missing.whitespace}
57 * </li>
58 * <li>
59 * {@code javadoc.parse.rule.error}
60 * </li>
61 * <li>
62 * {@code javadoc.unclosedHtml}
63 * </li>
64 * <li>
65 * {@code javadoc.wrong.singleton.html.tag}
66 * </li>
67 * </ul>
68 *
69 * @since 8.32
70 */
71 @StatelessCheck
72 public class JavadocMissingWhitespaceAfterAsteriskCheck extends AbstractJavadocCheck {
73
74 /**
75 * A key is pointing to the warning message text in "messages.properties" file.
76 */
77 public static final String MSG_KEY = "javadoc.missing.whitespace";
78
79 @Override
80 public int[] getDefaultJavadocTokens() {
81 return new int[] {
82 JavadocTokenTypes.JAVADOC,
83 JavadocTokenTypes.LEADING_ASTERISK,
84 };
85 }
86
87 @Override
88 public int[] getRequiredJavadocTokens() {
89 return getAcceptableJavadocTokens();
90 }
91
92 @Override
93 public void visitJavadocToken(DetailNode detailNode) {
94 final DetailNode textNode;
95
96 if (detailNode.getType() == JavadocTokenTypes.JAVADOC) {
97 textNode = JavadocUtil.getFirstChild(detailNode);
98 }
99 else {
100 textNode = JavadocUtil.getNextSibling(detailNode);
101 }
102
103 if (textNode != null && textNode.getType() != JavadocTokenTypes.EOF) {
104 final String text = textNode.getText();
105 final int lastAsteriskPosition = getLastLeadingAsteriskPosition(text);
106
107 if (!isLast(lastAsteriskPosition, text)
108 && !Character.isWhitespace(text.charAt(lastAsteriskPosition + 1))) {
109 log(textNode.getLineNumber(), textNode.getColumnNumber(), MSG_KEY);
110 }
111 }
112 }
113
114 /**
115 * Checks if the character position is the last one of the string.
116 *
117 * @param position the position of the character
118 * @param text String literal.
119 * @return true if the character position is the last one of the string.
120 *
121 */
122 private static boolean isLast(int position, String text) {
123 return position == text.length() - 1;
124 }
125
126 /**
127 * Finds the position of the last leading asterisk in the string.
128 * If {@code text} contains no leading asterisk, -1 will be returned.
129 *
130 * @param text String literal.
131 * @return the index of the last leading asterisk.
132 *
133 */
134 private static int getLastLeadingAsteriskPosition(String text) {
135 int index = -1;
136
137 for (int i = 0; i < text.length(); i++) {
138 if (text.charAt(i) != '*') {
139 break;
140 }
141 index++;
142 }
143
144 return index;
145 }
146
147 }