001///////////////////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code and other text files for adherence to a set of rules.
003// Copyright (C) 2001-2023 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.annotation;
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.AnnotationUtil;
027import com.puppycrawl.tools.checkstyle.utils.CheckUtil;
028
029/**
030 * <p>
031 * Checks that all package annotations are in the package-info.java file.
032 * </p>
033 * <p>
034 * For Java SE8 and above, placement of package annotations in the package-info.java
035 * file is enforced by the compiler and this check is not necessary.
036 * </p>
037 * <p>
038 * For Java SE7 and below, the Java Language Specification highly recommends
039 * but doesn't require that annotations are placed in the package-info.java file,
040 * and this check can help to enforce that placement.
041 * </p>
042 * <p>
043 * See <a href="https://docs.oracle.com/javase/specs/jls/se11/html/jls-7.html#jls-7.4.1">
044 * Java Language Specification, &#167;7.4.1</a> for more info.
045 * </p>
046 * <p>
047 * To configure the check:
048 * </p>
049 * <pre>
050 * &lt;module name=&quot;PackageAnnotation&quot;/&gt;
051 * </pre>
052 * <p>Example of validating MyClass.java:</p>
053 * <pre>
054 * &#64;Deprecated
055 * package com.example.annotations.packageannotation; //violation
056 * </pre>
057 * <p>Example of fixing violation in MyClass.java:</p>
058 * <pre>
059 * package com.example.annotations.packageannotation; //ok
060 * </pre>
061 * <p>Example of validating package-info.java:</p>
062 * <pre>
063 * &#64;Deprecated
064 * package com.example.annotations.packageannotation; //ok
065 * </pre>
066 * <p>
067 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
068 * </p>
069 * <p>
070 * Violation Message Keys:
071 * </p>
072 * <ul>
073 * <li>
074 * {@code annotation.package.location}
075 * </li>
076 * </ul>
077 *
078 * @since 5.0
079 */
080@StatelessCheck
081public class PackageAnnotationCheck extends AbstractCheck {
082
083    /**
084     * A key is pointing to the warning message text in "messages.properties"
085     * file.
086     */
087    public static final String MSG_KEY = "annotation.package.location";
088
089    @Override
090    public int[] getDefaultTokens() {
091        return getRequiredTokens();
092    }
093
094    @Override
095    public int[] getRequiredTokens() {
096        return new int[] {
097            TokenTypes.PACKAGE_DEF,
098        };
099    }
100
101    @Override
102    public int[] getAcceptableTokens() {
103        return getRequiredTokens();
104    }
105
106    @Override
107    public void visitToken(final DetailAST ast) {
108        final boolean containsAnnotation =
109            AnnotationUtil.containsAnnotation(ast);
110
111        if (containsAnnotation && !CheckUtil.isPackageInfo(getFilePath())) {
112            log(ast, MSG_KEY);
113        }
114    }
115
116}