001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2020 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 com.puppycrawl.tools.checkstyle.StatelessCheck;
023import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
024import com.puppycrawl.tools.checkstyle.api.DetailAST;
025import com.puppycrawl.tools.checkstyle.api.TokenTypes;
026import com.puppycrawl.tools.checkstyle.utils.JavadocUtil;
027
028/**
029 * <p>
030 * Checks that Javadocs are located at the correct position. As specified at
031 * <a href="https://docs.oracle.com/en/java/javase/11/docs/specs/doc-comment-spec.html">
032 * Documentation Comment Specification for the Standard Doclet</a>, Javadocs are recognized
033 * only when placed immediately before module, package, class, interface,
034 * constructor, method, or field declarations. Any other position, like in the
035 * body of a method, will be ignored by the javadoc tool and is considered
036 * invalid by this check.
037 * </p>
038 * <p>
039 * To configure the check:
040 * </p>
041 * <pre>
042 * &lt;module name="InvalidJavadocPosition"/&gt;
043 * </pre>
044 * <p>
045 * The following code produces a violation because Javadocs should be before all annotations of
046 * the Javadoc's target:
047 * </p>
048 * <pre>
049 * &#064;SuppressWarnings("serial")
050 * /**
051 *  * This comment looks like javadoc but it at an invalid location.
052 *  * Therefore, the text will not get into TestClass.html and the check will produce a violation.
053 *  *&#47;
054 * public class TestClass {
055 * }
056 * </pre>
057 *
058 * @since 8.23
059 */
060@StatelessCheck
061public class InvalidJavadocPositionCheck extends AbstractCheck {
062
063    /**
064     * A key is pointing to the warning message text in "messages.properties"
065     * file.
066     */
067    public static final String MSG_KEY = "invalid.position";
068
069    @Override
070    public int[] getDefaultTokens() {
071        return new int[] {
072            TokenTypes.BLOCK_COMMENT_BEGIN,
073        };
074    }
075
076    @Override
077    public int[] getAcceptableTokens() {
078        return getDefaultTokens();
079    }
080
081    @Override
082    public int[] getRequiredTokens() {
083        return getDefaultTokens();
084    }
085
086    @Override
087    public boolean isCommentNodesRequired() {
088        return true;
089    }
090
091    @Override
092    public void visitToken(DetailAST ast) {
093        final String commentContent = JavadocUtil.getBlockCommentContent(ast);
094
095        if (JavadocUtil.isJavadocComment(commentContent)
096                && !JavadocUtil.isCorrectJavadocPosition(ast)) {
097            log(ast, MSG_KEY);
098        }
099    }
100
101}