1 ///////////////////////////////////////////////////////////////////////////////////////////////
2 // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
3 // Copyright (C) 2001-2026 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;
21
22 import java.util.ArrayList;
23 import java.util.List;
24
25 import com.puppycrawl.tools.checkstyle.StatelessCheck;
26 import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
27 import com.puppycrawl.tools.checkstyle.api.DetailAST;
28 import com.puppycrawl.tools.checkstyle.api.TokenTypes;
29 import com.puppycrawl.tools.checkstyle.utils.JavadocUtil;
30
31 /**
32 * <div>
33 * Checks if the
34 * <a href="https://www.oracle.com/java/technologies/javase/codeconventions-comments.html">
35 * multi-line comments</a> have leading asterisks on each line.
36 * </div>
37 *
38 * <p>
39 * Every line in multi-line comment should have leading asterisk including blank line.
40 * </p>
41 *
42 * @since 13.9.0
43 */
44 @StatelessCheck
45 public class MultilineCommentLeadingAsteriskPresenceCheck extends AbstractCheck {
46
47 /**
48 * A key is pointing to the warning message text in "messages.properties"
49 * file.
50 */
51 public static final String MSG_MISSING_ASTERISK = "multiline.comment.missing.asterisk";
52
53 /**
54 * Creates a new {@code MultilineCommentLeadingAsteriskPresenceCheck} instance.
55 */
56 public MultilineCommentLeadingAsteriskPresenceCheck() {
57 // no code by default
58 }
59
60 @Override
61 public int[] getRequiredTokens() {
62 return new int[] {
63 TokenTypes.BLOCK_COMMENT_BEGIN,
64 };
65 }
66
67 @Override
68 public int[] getAcceptableTokens() {
69 return getRequiredTokens();
70 }
71
72 @Override
73 public int[] getDefaultTokens() {
74 return getRequiredTokens();
75 }
76
77 @Override
78 public boolean isCommentNodesRequired() {
79 return true;
80 }
81
82 @Override
83 public void visitToken(DetailAST ast) {
84 if (!JavadocUtil.isJavadocComment(ast)) {
85 final String commentText = JavadocUtil.getBlockCommentContent(ast);
86 int lineNumber = ast.getLineNo();
87 final int commentEndLineNumber = ast.getLastChild().getLineNo();
88 final List<String> lines = commentText.lines().toList();
89 final List<Integer> nonAsteriskLineNumbers = new ArrayList<>();
90 for (int cur = 1; cur < lines.size(); cur++) {
91 lineNumber++;
92 final String line = lines.get(cur).trim();
93 // is block comment end
94 if (lineNumber == commentEndLineNumber && line.isEmpty()) {
95 continue;
96 }
97 if (!line.startsWith("*")) {
98 nonAsteriskLineNumbers.add(lineNumber);
99 }
100 }
101
102 if (!nonAsteriskLineNumbers.isEmpty()) {
103 final String allLineNumbers = nonAsteriskLineNumbers.toString();
104 log(ast, MSG_MISSING_ASTERISK, allLineNumbers.substring(1,
105 allLineNumbers.length() - 1));
106 }
107 }
108 }
109
110 }