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.annotation;
021
022import java.util.regex.Matcher;
023import java.util.regex.Pattern;
024
025import com.puppycrawl.tools.checkstyle.StatelessCheck;
026import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
027import com.puppycrawl.tools.checkstyle.api.DetailAST;
028import com.puppycrawl.tools.checkstyle.api.TextBlock;
029import com.puppycrawl.tools.checkstyle.api.TokenTypes;
030import com.puppycrawl.tools.checkstyle.checks.javadoc.JavadocTagInfo;
031import com.puppycrawl.tools.checkstyle.utils.AnnotationUtil;
032import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
033
034/**
035 * <p>
036 * This class is used to verify that the {@link Override Override}
037 * annotation is present when the inheritDoc javadoc tag is present.
038 * </p>
039 *
040 * <p>
041 * Rationale: The {@link Override Override} annotation helps
042 * compiler tools ensure that an override is actually occurring.  It is
043 * quite easy to accidentally overload a method or hide a static method
044 * and using the {@link Override Override} annotation points
045 * out these problems.
046 * </p>
047 *
048 * <p>
049 * This check will log a violation if using the inheritDoc tag on a method that
050 * is not valid (ex: private, or static method).
051 * </p>
052 *
053 * <p>
054 * There is a slight difference between the Override annotation in Java 5 versus
055 * Java 6 and above. In Java 5, any method overridden from an interface cannot
056 * be annotated with Override. In Java 6 this behavior is allowed.
057 * </p>
058 *
059 * <p>
060 * As a result of the aforementioned difference between Java 5 and Java 6, a
061 * property called {@code javaFiveCompatibility } is available. This
062 * property will only check classes, interfaces, etc. that do not contain the
063 * extends or implements keyword or are not anonymous classes. This means it
064 * only checks methods overridden from {@code java.lang.Object}
065 *
066 * <b>Java 5 Compatibility mode severely limits this check. It is recommended to
067 * only use it on Java 5 source</b>
068 * </p>
069 *
070 * <pre>
071 * &lt;module name=&quot;MissingOverride&quot;&gt;
072 *    &lt;property name=&quot;javaFiveCompatibility&quot;
073 *        value=&quot;true&quot;/&gt;
074 * &lt;/module&gt;
075 * </pre>
076 *
077 */
078@StatelessCheck
079public final class MissingOverrideCheck extends AbstractCheck {
080
081    /**
082     * A key is pointing to the warning message text in "messages.properties"
083     * file.
084     */
085    public static final String MSG_KEY_TAG_NOT_VALID_ON = "tag.not.valid.on";
086
087    /**
088     * A key is pointing to the warning message text in "messages.properties"
089     * file.
090     */
091    public static final String MSG_KEY_ANNOTATION_MISSING_OVERRIDE =
092        "annotation.missing.override";
093
094    /** {@link Override Override} annotation name. */
095    private static final String OVERRIDE = "Override";
096
097    /** Fully-qualified {@link Override Override} annotation name. */
098    private static final String FQ_OVERRIDE = "java.lang." + OVERRIDE;
099
100    /** Compiled regexp to match Javadoc tags with no argument and {}. */
101    private static final Pattern MATCH_INHERIT_DOC =
102            CommonUtil.createPattern("\\{\\s*@(inheritDoc)\\s*\\}");
103
104    /**
105     * Java 5 compatibility option.
106     * @see #setJavaFiveCompatibility(boolean)
107     */
108    private boolean javaFiveCompatibility;
109
110    /**
111     * Sets Java 5 compatibility mode.
112     *
113     * <p>
114     * In Java 5, this check could flag code that is not valid for the Override
115     * annotation even though it is a proper override. See the class
116     * documentation for more information.
117     * </p>
118     *
119     * <p>
120     * Set this to true to turn on Java 5 compatibility mode. Set this to
121     * false to turn off Java 5 compatibility mode.
122     * </p>
123     *
124     * @param compatibility compatibility or not
125     */
126    public void setJavaFiveCompatibility(final boolean compatibility) {
127        javaFiveCompatibility = compatibility;
128    }
129
130    @Override
131    public int[] getDefaultTokens() {
132        return getRequiredTokens();
133    }
134
135    @Override
136    public int[] getAcceptableTokens() {
137        return getRequiredTokens();
138    }
139
140    @Override
141    public int[] getRequiredTokens() {
142        return new int[]
143        {TokenTypes.METHOD_DEF, };
144    }
145
146    // -@cs[CyclomaticComplexity] Too complex to break apart.
147    @Override
148    public void visitToken(final DetailAST ast) {
149        final TextBlock javadoc =
150            getFileContents().getJavadocBefore(ast.getLineNo());
151
152        final boolean containsTag = containsJavadocTag(javadoc);
153        if (containsTag && !JavadocTagInfo.INHERIT_DOC.isValidOn(ast)) {
154            log(ast.getLineNo(), MSG_KEY_TAG_NOT_VALID_ON,
155                JavadocTagInfo.INHERIT_DOC.getText());
156        }
157        else {
158            boolean check = true;
159
160            if (javaFiveCompatibility) {
161                final DetailAST defOrNew = ast.getParent().getParent();
162
163                if (defOrNew.findFirstToken(TokenTypes.EXTENDS_CLAUSE) != null
164                    || defOrNew.findFirstToken(TokenTypes.IMPLEMENTS_CLAUSE) != null
165                    || defOrNew.getType() == TokenTypes.LITERAL_NEW) {
166                    check = false;
167                }
168            }
169
170            if (check
171                && containsTag
172                && !AnnotationUtil.containsAnnotation(ast, OVERRIDE)
173                && !AnnotationUtil.containsAnnotation(ast, FQ_OVERRIDE)) {
174                log(ast.getLineNo(), MSG_KEY_ANNOTATION_MISSING_OVERRIDE);
175            }
176        }
177    }
178
179    /**
180     * Checks to see if the text block contains a inheritDoc tag.
181     *
182     * @param javadoc the javadoc of the AST
183     * @return true if contains the tag
184     */
185    private static boolean containsJavadocTag(final TextBlock javadoc) {
186        boolean javadocTag = false;
187
188        if (javadoc != null) {
189            final String[] lines = javadoc.getText();
190
191            for (final String line : lines) {
192                final Matcher matchInheritDoc =
193                    MATCH_INHERIT_DOC.matcher(line);
194
195                if (matchInheritDoc.find()) {
196                    javadocTag = true;
197                    break;
198                }
199            }
200        }
201        return javadocTag;
202    }
203
204}