001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2021 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;
027
028/**
029 * <p>
030 * Checks that all package annotations are in the package-info.java file.
031 * </p>
032 * <p>
033 * For Java SE8 and above, placement of package annotations in the package-info.java
034 * file is enforced by the compiler and this check is not necessary.
035 * </p>
036 * <p>
037 * For Java SE7 and below, the Java Language Specification highly recommends
038 * but doesn't require that annotations are placed in the package-info.java file,
039 * and this check can help to enforce that placement.
040 * </p>
041 * <p>
042 * See <a href="https://docs.oracle.com/javase/specs/jls/se11/html/jls-7.html#jls-7.4.1">
043 * Java Language Specification, &#167;7.4.1</a> for more info.
044 * </p>
045 * <p>
046 * To configure the check:
047 * </p>
048 * <pre>
049 * &lt;module name=&quot;PackageAnnotation&quot;/&gt;
050 * </pre>
051 * <p>Example of validating MyClass.java:</p>
052 * <pre>
053 * &#64;Deprecated
054 * package com.example.annotations.packageannotation; //violation
055 * </pre>
056 * <p>Example of fixing violation in MyClass.java:</p>
057 * <pre>
058 * package com.example.annotations.packageannotation; //ok
059 * </pre>
060 * <p>Example of validating package-info.java:</p>
061 * <pre>
062 * &#64;Deprecated
063 * package com.example.annotations.packageannotation; //ok
064 * </pre>
065 * <p>
066 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
067 * </p>
068 * <p>
069 * Violation Message Keys:
070 * </p>
071 * <ul>
072 * <li>
073 * {@code annotation.package.location}
074 * </li>
075 * </ul>
076 *
077 * @since 5.0
078 */
079@StatelessCheck
080public class PackageAnnotationCheck extends AbstractCheck {
081
082    /**
083     * A key is pointing to the warning message text in "messages.properties"
084     * file.
085     */
086    public static final String MSG_KEY = "annotation.package.location";
087
088    @Override
089    public int[] getDefaultTokens() {
090        return getRequiredTokens();
091    }
092
093    @Override
094    public int[] getRequiredTokens() {
095        return new int[] {
096            TokenTypes.PACKAGE_DEF,
097        };
098    }
099
100    @Override
101    public int[] getAcceptableTokens() {
102        return getRequiredTokens();
103    }
104
105    @Override
106    public void visitToken(final DetailAST ast) {
107        final boolean containsAnnotation =
108            AnnotationUtil.containsAnnotation(ast);
109        final boolean inPackageInfo =
110            getFileContents().inPackageInfo();
111
112        if (containsAnnotation && !inPackageInfo) {
113            log(ast, MSG_KEY);
114        }
115    }
116
117}