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 java.util.Optional;
23
24 import com.puppycrawl.tools.checkstyle.StatelessCheck;
25 import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
26 import com.puppycrawl.tools.checkstyle.api.DetailAST;
27 import com.puppycrawl.tools.checkstyle.api.TokenTypes;
28 import com.puppycrawl.tools.checkstyle.utils.CheckUtil;
29 import com.puppycrawl.tools.checkstyle.utils.JavadocUtil;
30
31 /**
32 * <div>
33 * Checks for missing package definition Javadoc comments in package-info.java files.
34 * </div>
35 *
36 * <p>
37 * Rationale: description and other related documentation for a package can be written up
38 * in the package-info.java file and it gets used in the production of the Javadocs.
39 * See <a
40 * href="https://docs.oracle.com/javase/8/docs/technotes/tools/windows/javadoc.html#packagecomment"
41 * >link</a> for more info.
42 * </p>
43 *
44 * <p>
45 * This check specifically only validates package definitions. It will not validate any methods or
46 * interfaces declared in the package-info.java file.
47 * </p>
48 *
49 * <p>
50 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
51 * </p>
52 *
53 * <p>
54 * Violation Message Keys:
55 * </p>
56 * <ul>
57 * <li>
58 * {@code package.javadoc.missing}
59 * </li>
60 * </ul>
61 *
62 * @since 8.22
63 */
64 @StatelessCheck
65 public class MissingJavadocPackageCheck extends AbstractCheck {
66
67 /**
68 * A key is pointing to the warning message text in "messages.properties"
69 * file.
70 */
71 public static final String MSG_PKG_JAVADOC_MISSING = "package.javadoc.missing";
72
73 @Override
74 public int[] getDefaultTokens() {
75 return getRequiredTokens();
76 }
77
78 @Override
79 public int[] getAcceptableTokens() {
80 return getRequiredTokens();
81 }
82
83 @Override
84 public int[] getRequiredTokens() {
85 return new int[] {TokenTypes.PACKAGE_DEF};
86 }
87
88 @Override
89 public boolean isCommentNodesRequired() {
90 return true;
91 }
92
93 @Override
94 public void visitToken(DetailAST ast) {
95 if (CheckUtil.isPackageInfo(getFilePath()) && !hasJavadoc(ast)) {
96 log(ast, MSG_PKG_JAVADOC_MISSING);
97 }
98 }
99
100 /**
101 * Checks that there is javadoc before ast.
102 * Because of <a href="https://github.com/checkstyle/checkstyle/issues/4392">parser bug</a>
103 * parser can place javadoc comment either as previous sibling of package definition
104 * or (if there is annotation between package def and javadoc) inside package definition tree.
105 * So we should look for javadoc in both places.
106 *
107 * @param ast {@link TokenTypes#PACKAGE_DEF} token to check
108 * @return true if there is javadoc, false otherwise
109 */
110 private static boolean hasJavadoc(DetailAST ast) {
111 final boolean hasJavadocBefore = ast.getPreviousSibling() != null
112 && isJavadoc(ast.getPreviousSibling());
113 return hasJavadocBefore || hasJavadocAboveAnnotation(ast);
114 }
115
116 /**
117 * Checks javadoc existence in annotations list.
118 *
119 * @param ast package def
120 * @return true if there is a javadoc, false otherwise
121 */
122 private static boolean hasJavadocAboveAnnotation(DetailAST ast) {
123 final Optional<DetailAST> firstAnnotationChild = Optional.of(ast.getFirstChild())
124 .map(DetailAST::getFirstChild)
125 .map(DetailAST::getFirstChild);
126 boolean result = false;
127 if (firstAnnotationChild.isPresent()) {
128 for (DetailAST child = firstAnnotationChild.orElseThrow(); child != null;
129 child = child.getNextSibling()) {
130 if (isJavadoc(child)) {
131 result = true;
132 break;
133 }
134 }
135 }
136 return result;
137 }
138
139 /**
140 * Checks that ast is a javadoc comment.
141 *
142 * @param ast token to check
143 * @return true if ast is a javadoc comment, false otherwise
144 */
145 private static boolean isJavadoc(DetailAST ast) {
146 return ast.getType() == TokenTypes.BLOCK_COMMENT_BEGIN && JavadocUtil.isJavadocComment(ast);
147 }
148 }