View Javadoc
1   ////////////////////////////////////////////////////////////////////////////////
2   // checkstyle: Checks Java source code for adherence to a set of rules.
3   // Copyright (C) 2001-2017 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.ArrayList;
23  import java.util.Arrays;
24  import java.util.List;
25  import java.util.stream.Collectors;
26  
27  import com.puppycrawl.tools.checkstyle.api.DetailAST;
28  import com.puppycrawl.tools.checkstyle.api.DetailNode;
29  import com.puppycrawl.tools.checkstyle.api.JavadocTokenTypes;
30  import com.puppycrawl.tools.checkstyle.utils.JavadocUtils;
31  
32  /**
33   * Checks that a JavaDoc block can fit on a single line and doesn't
34   * contain at-clauses. Javadoc comment that contains at least one at-clause
35   * should be formatted in a few lines.<br>
36   * All inline at-clauses are ignored by default.
37   *
38   * <p>The Check has the following properties:
39   * <br><b>ignoredTags</b> - allows to specify a list of at-clauses
40   * (including custom at-clauses) to be ignored by the check.
41   * <br><b>ignoreInlineTags</b> - whether inline at-clauses must be ignored.
42   * </p>
43   *
44   * <p>Default configuration:
45   * <pre>
46   * &lt;module name=&quot;SingleLineJavadoc&quot;/&gt;
47   * </pre>
48   * To specify a list of ignored at-clauses and make inline at-clauses not ignored in general:
49   * <pre>
50   * &lt;module name=&quot;SingleLineJavadoc&quot;&gt;
51   *     &lt;property name=&quot;ignoredTags&quot; value=&quot;&#64;inheritDoc, &#64;link&quot;/&gt;
52   *     &lt;property name=&quot;ignoreInlineTags&quot; value=&quot;false&quot;/&gt;
53   * &lt;/module&gt;
54   * </pre>
55   *
56   * @author baratali
57   * @author maxvetrenko
58   * @author vladlis
59   *
60   */
61  public class SingleLineJavadocCheck extends AbstractJavadocCheck {
62  
63      /**
64       * A key is pointing to the warning message text in "messages.properties"
65       * file.
66       */
67      public static final String MSG_KEY = "singleline.javadoc";
68  
69      /**
70       * Allows to specify a list of tags to be ignored by check.
71       */
72      private List<String> ignoredTags = new ArrayList<>();
73  
74      /** Whether inline tags must be ignored. **/
75      private boolean ignoreInlineTags = true;
76  
77      /**
78       * Sets a list of tags to be ignored by check.
79       *
80       * @param tags to be ignored by check.
81       */
82      public void setIgnoredTags(String... tags) {
83          ignoredTags = Arrays.stream(tags).collect(Collectors.toList());
84      }
85  
86      /**
87       * Sets whether inline tags must be ignored.
88       *
89       * @param ignoreInlineTags whether inline tags must be ignored.
90       */
91      public void setIgnoreInlineTags(boolean ignoreInlineTags) {
92          this.ignoreInlineTags = ignoreInlineTags;
93      }
94  
95      @Override
96      public int[] getDefaultJavadocTokens() {
97          return new int[] {
98              JavadocTokenTypes.JAVADOC,
99          };
100     }
101 
102     @Override
103     public int[] getRequiredJavadocTokens() {
104         return getAcceptableJavadocTokens();
105     }
106 
107     @Override
108     public void visitJavadocToken(DetailNode ast) {
109         if (isSingleLineJavadoc(getBlockCommentAst())
110                 && (hasJavadocTags(ast) || !ignoreInlineTags && hasJavadocInlineTags(ast))) {
111             log(ast.getLineNumber(), MSG_KEY);
112         }
113     }
114 
115     /**
116      * Checks if comment is single line comment.
117      *
118      * @param blockCommentStart the AST tree in which a block comment starts
119      * @return true, if comment is single line comment.
120      */
121     private static boolean isSingleLineJavadoc(DetailAST blockCommentStart) {
122         final DetailAST blockCommentEnd = blockCommentStart.getLastChild();
123         return blockCommentStart.getLineNo() == blockCommentEnd.getLineNo();
124     }
125 
126     /**
127      * Checks if comment has javadoc tags which are not ignored. Also works
128      * on custom tags. As block tags can be interpreted only at the beginning of a line,
129      * only the first instance is checked.
130      *
131      * @param javadocRoot javadoc root node.
132      * @return true, if comment has javadoc tags which are not ignored.
133      * @see <a href=
134      * https://docs.oracle.com/javase/7/docs/technotes/tools/windows/javadoc.html#blockandinlinetags>
135      * Block and inline tags</a>
136      */
137     private boolean hasJavadocTags(DetailNode javadocRoot) {
138         final DetailNode javadocTagSection =
139                 JavadocUtils.findFirstToken(javadocRoot, JavadocTokenTypes.JAVADOC_TAG);
140         return javadocTagSection != null && !isTagIgnored(javadocTagSection);
141     }
142 
143     /**
144      * Checks if comment has in-line tags which are not ignored.
145      *
146      * @param javadocRoot javadoc root node.
147      * @return true, if comment has in-line tags which are not ignored.
148      * @see <a href=
149      * https://docs.oracle.com/javase/7/docs/technotes/tools/windows/javadoc.html#javadoctags>
150      * JavadocTags</a>
151      */
152     private boolean hasJavadocInlineTags(DetailNode javadocRoot) {
153         DetailNode javadocTagSection =
154                 JavadocUtils.findFirstToken(javadocRoot, JavadocTokenTypes.JAVADOC_INLINE_TAG);
155         boolean foundTag = false;
156         while (javadocTagSection != null) {
157             if (!isTagIgnored(javadocTagSection)) {
158                 foundTag = true;
159                 break;
160             }
161             javadocTagSection = JavadocUtils.getNextSibling(
162                     javadocTagSection, JavadocTokenTypes.JAVADOC_INLINE_TAG);
163         }
164         return foundTag;
165     }
166 
167     /**
168      * Checks if list of ignored tags contains javadocTagSection's javadoc tag.
169      *
170      * @param javadocTagSection to check javadoc tag in.
171      * @return true, if ignoredTags contains javadocTagSection's javadoc tag.
172      */
173     private boolean isTagIgnored(DetailNode javadocTagSection) {
174         return ignoredTags.contains(JavadocUtils.getTagName(javadocTagSection));
175     }
176 }