001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2019 the original author or authors.
004//
005// This library is free software; you can redistribute it and/or
006// modify it under the terms of the GNU Lesser General Public
007// License as published by the Free Software Foundation; either
008// version 2.1 of the License, or (at your option) any later version.
009//
010// This library is distributed in the hope that it will be useful,
011// but WITHOUT ANY WARRANTY; without even the implied warranty of
012// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
013// Lesser General Public License for more details.
014//
015// You should have received a copy of the GNU Lesser General Public
016// License along with this library; if not, write to the Free Software
017// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
018////////////////////////////////////////////////////////////////////////////////
019
020package com.puppycrawl.tools.checkstyle.checks.javadoc;
021
022import java.util.ArrayList;
023import java.util.Arrays;
024import java.util.List;
025import java.util.stream.Collectors;
026
027import com.puppycrawl.tools.checkstyle.StatelessCheck;
028import com.puppycrawl.tools.checkstyle.api.DetailAST;
029import com.puppycrawl.tools.checkstyle.api.DetailNode;
030import com.puppycrawl.tools.checkstyle.api.JavadocTokenTypes;
031import com.puppycrawl.tools.checkstyle.utils.JavadocUtil;
032
033/**
034 * Checks that a JavaDoc block can fit on a single line and doesn't
035 * contain at-clauses. Javadoc comment that contains at least one at-clause
036 * should be formatted in a few lines.<br>
037 * All inline at-clauses are ignored by default.
038 *
039 * <p>The Check has the following properties:
040 * <br><b>ignoredTags</b> - allows to specify a list of at-clauses
041 * (including custom at-clauses) to be ignored by the check.
042 * <br><b>ignoreInlineTags</b> - whether inline at-clauses must be ignored.
043 * </p>
044 *
045 * <p>Default configuration:
046 * <pre>
047 * &lt;module name=&quot;SingleLineJavadoc&quot;/&gt;
048 * </pre>
049 * To specify a list of ignored at-clauses and make inline at-clauses not ignored in general:
050 * <pre>
051 * &lt;module name=&quot;SingleLineJavadoc&quot;&gt;
052 *     &lt;property name=&quot;ignoredTags&quot; value=&quot;&#64;inheritDoc, &#64;link&quot;/&gt;
053 *     &lt;property name=&quot;ignoreInlineTags&quot; value=&quot;false&quot;/&gt;
054 * &lt;/module&gt;
055 * </pre>
056 *
057 *
058 */
059@StatelessCheck
060public class SingleLineJavadocCheck extends AbstractJavadocCheck {
061
062    /**
063     * A key is pointing to the warning message text in "messages.properties"
064     * file.
065     */
066    public static final String MSG_KEY = "singleline.javadoc";
067
068    /**
069     * Allows to specify a list of tags to be ignored by check.
070     */
071    private List<String> ignoredTags = new ArrayList<>();
072
073    /** Whether inline tags must be ignored. **/
074    private boolean ignoreInlineTags = true;
075
076    /**
077     * Sets a list of tags to be ignored by check.
078     *
079     * @param tags to be ignored by check.
080     */
081    public void setIgnoredTags(String... tags) {
082        ignoredTags = Arrays.stream(tags).collect(Collectors.toList());
083    }
084
085    /**
086     * Sets whether inline tags must be ignored.
087     *
088     * @param ignoreInlineTags whether inline tags must be ignored.
089     */
090    public void setIgnoreInlineTags(boolean ignoreInlineTags) {
091        this.ignoreInlineTags = ignoreInlineTags;
092    }
093
094    @Override
095    public int[] getDefaultJavadocTokens() {
096        return new int[] {
097            JavadocTokenTypes.JAVADOC,
098        };
099    }
100
101    @Override
102    public int[] getRequiredJavadocTokens() {
103        return getAcceptableJavadocTokens();
104    }
105
106    @Override
107    public void visitJavadocToken(DetailNode ast) {
108        if (isSingleLineJavadoc(getBlockCommentAst())
109                && (hasJavadocTags(ast) || !ignoreInlineTags && hasJavadocInlineTags(ast))) {
110            log(ast.getLineNumber(), MSG_KEY);
111        }
112    }
113
114    /**
115     * Checks if comment is single line comment.
116     *
117     * @param blockCommentStart the AST tree in which a block comment starts
118     * @return true, if comment is single line comment.
119     */
120    private static boolean isSingleLineJavadoc(DetailAST blockCommentStart) {
121        final DetailAST blockCommentEnd = blockCommentStart.getLastChild();
122        return blockCommentStart.getLineNo() == blockCommentEnd.getLineNo();
123    }
124
125    /**
126     * Checks if comment has javadoc tags which are not ignored. Also works
127     * on custom tags. As block tags can be interpreted only at the beginning of a line,
128     * only the first instance is checked.
129     *
130     * @param javadocRoot javadoc root node.
131     * @return true, if comment has javadoc tags which are not ignored.
132     * @see <a href=
133     * "https://docs.oracle.com/javase/7/docs/technotes/tools/windows/javadoc.html#blockandinlinetags">
134     * Block and inline tags</a>
135     */
136    private boolean hasJavadocTags(DetailNode javadocRoot) {
137        final DetailNode javadocTagSection =
138                JavadocUtil.findFirstToken(javadocRoot, JavadocTokenTypes.JAVADOC_TAG);
139        return javadocTagSection != null && !isTagIgnored(javadocTagSection);
140    }
141
142    /**
143     * Checks if comment has in-line tags which are not ignored.
144     *
145     * @param javadocRoot javadoc root node.
146     * @return true, if comment has in-line tags which are not ignored.
147     * @see <a href=
148     * "https://docs.oracle.com/javase/7/docs/technotes/tools/windows/javadoc.html#javadoctags">
149     * JavadocTags</a>
150     */
151    private boolean hasJavadocInlineTags(DetailNode javadocRoot) {
152        DetailNode javadocTagSection =
153                JavadocUtil.findFirstToken(javadocRoot, JavadocTokenTypes.JAVADOC_INLINE_TAG);
154        boolean foundTag = false;
155        while (javadocTagSection != null) {
156            if (!isTagIgnored(javadocTagSection)) {
157                foundTag = true;
158                break;
159            }
160            javadocTagSection = JavadocUtil.getNextSibling(
161                    javadocTagSection, JavadocTokenTypes.JAVADOC_INLINE_TAG);
162        }
163        return foundTag;
164    }
165
166    /**
167     * Checks if list of ignored tags contains javadocTagSection's javadoc tag.
168     *
169     * @param javadocTagSection to check javadoc tag in.
170     * @return true, if ignoredTags contains javadocTagSection's javadoc tag.
171     */
172    private boolean isTagIgnored(DetailNode javadocTagSection) {
173        return ignoredTags.contains(JavadocUtil.getTagName(javadocTagSection));
174    }
175
176}