001///////////////////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code and other text files for adherence to a set of rules.
003// Copyright (C) 2001-2026 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.Locale;
023
024import com.puppycrawl.tools.checkstyle.StatelessCheck;
025import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
026import com.puppycrawl.tools.checkstyle.api.DetailAST;
027import com.puppycrawl.tools.checkstyle.api.TokenTypes;
028import com.puppycrawl.tools.checkstyle.utils.JavadocUtil;
029import com.puppycrawl.tools.checkstyle.utils.TokenUtil;
030
031/**
032 * <div>
033 * Checks that the Javadoc block comment end <code class="language-java">*&#47;</code>
034 * position is either alone on its own line or on the same line as
035 * the block comment begin code <code class="language-java">&#47;**</code>.
036 * </div>
037 *
038 * <p>
039 * It is possible to enforce two different strategies:
040 * </p>
041 * <ul>
042 * <li>
043 * {@code alone} - The block comment end must be alone on its own line.
044 * This allows only multi-line Javadoc comments:
045 * <div class="wrapper"><pre class="prettyprint"><code class="language-java">
046 * &#47;**
047 *  * Multiple lines of Javadoc text are written here,
048 *  * wrapped normally...
049 *  *&#47;
050 * public void method();
051 * </code></pre></div>
052 * </li>
053 * <li>
054 * {@code alone_or_singleline} - The block comment end must be either
055 * alone on its own line or on the same line as the block comment begin.
056 * This allows multi-line Javadoc as well as single-line Javadoc comments:
057 * <div class="wrapper"><pre class="prettyprint"><code class="language-java">
058 * // Block comment end is alone on its own line
059 * &#47;**
060 *  * Multiple lines of Javadoc text are written here,
061 *  * wrapped normally...
062 *  *&#47;
063 * public void method();
064 *
065 * // Single-line Javadoc
066 * &#47;** Javadoc summary. *&#47;
067 * public void method1();
068 * </code></pre></div>
069 * </li>
070 * </ul>
071 *
072 * @since 13.3.0
073 */
074@StatelessCheck
075public class BlockCommentEndPositionCheck extends AbstractCheck {
076
077    /**
078     * A key is pointing to the warning message text in "messages.properties" file.
079     */
080    public static final String MSG_BLOCK_COMMENT_END = "block.comment.end";
081
082    /**
083     * Specify the strategy policy for the block comment end position.
084     */
085    private BlockCommentEndPositionOption strategy =
086            BlockCommentEndPositionOption.ALONE_OR_SINGLELINE;
087
088    @Override
089    public int[] getRequiredTokens() {
090        return new int[] {
091            TokenTypes.BLOCK_COMMENT_BEGIN,
092        };
093    }
094
095    @Override
096    public int[] getAcceptableTokens() {
097        return getRequiredTokens();
098    }
099
100    @Override
101    public int[] getDefaultTokens() {
102        return getRequiredTokens();
103    }
104
105    @Override
106    public boolean isCommentNodesRequired() {
107        return true;
108    }
109
110    /**
111     * Setter to specify the policy on strategy of the block comment end position.
112     *
113     * @param value string to decode strategy from
114     * @throws IllegalArgumentException if unable to decode
115     * @since 13.3.0
116     */
117    public void setStrategy(String value) {
118        strategy = BlockCommentEndPositionOption.valueOf(value.trim().toUpperCase(Locale.ENGLISH));
119    }
120
121    @Override
122    public void visitToken(DetailAST ast) {
123        final DetailAST lastChild = ast.getLastChild();
124        if (JavadocUtil.isJavadocComment(ast)
125                && (strategy == BlockCommentEndPositionOption.ALONE
126                || !TokenUtil.areOnSameLine(ast, lastChild))
127                && !isAlone(lastChild)) {
128            log(lastChild, MSG_BLOCK_COMMENT_END, "BLOCK_COMMENT_END");
129        }
130    }
131
132    /**
133     * Checks whether the block comment end token is located alone on its own line.
134     *
135     * @param ast the block comment end token
136     * @return true if block comment end is alone
137     */
138    private boolean isAlone(DetailAST ast) {
139        final String lineText = getLine(ast.getLineNo() - 1).trim();
140        return "*/".equals(lineText);
141    }
142}