001////////////////////////////////////////////////////////////////////////////////
002// checkstyle: Checks Java source code for adherence to a set of rules.
003// Copyright (C) 2001-2014  Oliver Burn
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////////////////////////////////////////////////////////////////////////////////
019package com.puppycrawl.tools.checkstyle.checks.annotation;
020
021import java.util.regex.Matcher;
022import java.util.regex.Pattern;
023
024import com.puppycrawl.tools.checkstyle.api.AnnotationUtility;
025import com.puppycrawl.tools.checkstyle.api.Check;
026import com.puppycrawl.tools.checkstyle.api.DetailAST;
027import com.puppycrawl.tools.checkstyle.api.JavadocTagInfo;
028import com.puppycrawl.tools.checkstyle.api.TextBlock;
029import com.puppycrawl.tools.checkstyle.api.TokenTypes;
030import com.puppycrawl.tools.checkstyle.api.Utils;
031
032/**
033 * <p>
034 * This class is used to verify that the {@link java.lang.Override Override}
035 * annotation is present when the inheritDoc javadoc tag is present.
036 * </p>
037 *
038 * <p>
039 * Rationale: The {@link java.lang.Override Override} annotation helps
040 * compiler tools ensure that an override is actually occurring.  It is
041 * quite easy to accidentally overload a method or hide a static method
042 * and using the {@link java.lang.Override Override} annotation points
043 * out these problems.
044 * </p>
045 *
046 * <p>
047 * This check will log a violation if using the inheritDoc tag on a method that
048 * is not valid (ex: private, or static method).
049 * </p>
050 *
051 * <p>
052 * There is a slight difference between the Override annotation in Java 5 versus
053 * Java 6 and above. In Java 5, any method overridden from an interface cannot
054 * be annotated with Override. In Java 6 this behavior is allowed.
055 * </p>
056 *
057 * <p>
058 * As a result of the aforementioned difference between Java 5 and Java 6, a
059 * property called <code> javaFiveCompatibility </code> is available. This
060 * property will only check classes, interfaces, etc. that do not contain the
061 * extends or implements keyword or are not anonymous classes. This means it
062 * only checks methods overridden from <code>java.lang.Object</code>
063 *
064 * <b>Java 5 Compatibility mode severely limits this check. It is recommended to
065 * only use it on Java 5 source</b>
066 * </p>
067 *
068 * <pre>
069 * &lt;module name=&quot;MissingOverride&quot;&gt;
070 *    &lt;property name=&quot;javaFiveCompatibility&quot;
071 *        value=&quot;true&quot;/&gt;
072 * &lt;/module&gt;
073 * </pre>
074 *
075 * @author Travis Schneeberger
076 */
077public final class MissingOverrideCheck extends Check
078{
079    /** {@link Override Override} annotation name */
080    private static final String OVERRIDE = "Override";
081
082    /** fully-qualified {@link Override Override} annotation name */
083    private static final String FQ_OVERRIDE = "java.lang." + OVERRIDE;
084
085    /** compiled regexp to match Javadoc tags with no argument and {} * */
086    private static final Pattern MATCH_INHERITDOC =
087        Utils.createPattern("\\{\\s*@(inheritDoc)\\s*\\}");
088
089    /** @see #setJavaFiveCompatibility(boolean) */
090    private boolean mJavaFiveCompatibility;
091
092    /**
093     * Sets Java 5 compatibility mode.
094     *
095     * <p>
096     * In Java 5, this check could flag code that is not valid for the Override
097     * annotation even though it is a proper override. See the class
098     * documentation for more information.
099     * </p>
100     *
101     * <p>
102     * Set this to true to turn on Java 5 compatibility mode. Set this to
103     * false to turn off Java 5 compatibility mode.
104     * </p>
105     *
106     * @param aCompatibility compatibility or not
107     */
108    public void setJavaFiveCompatibility(final boolean aCompatibility)
109    {
110        this.mJavaFiveCompatibility = aCompatibility;
111    }
112
113    /** {@inheritDoc} */
114    @Override
115    public int[] getDefaultTokens()
116    {
117        return this.getRequiredTokens();
118    }
119
120    /** {@inheritDoc} */
121    @Override
122    public int[] getAcceptableTokens()
123    {
124        return this.getRequiredTokens();
125    }
126
127    /** {@inheritDoc} */
128    @Override
129    public int[] getRequiredTokens()
130    {
131        return new int[]
132        {TokenTypes.METHOD_DEF, };
133    }
134
135    /** {@inheritDoc} */
136    @Override
137    public void visitToken(final DetailAST aAST)
138    {
139        final TextBlock javadoc =
140            this.getFileContents().getJavadocBefore(aAST.getLineNo());
141
142
143        final boolean containsTag = this.containsJavadocTag(javadoc);
144        if (containsTag && !JavadocTagInfo.INHERIT_DOC.isValidOn(aAST)) {
145            this.log(aAST.getLineNo(), "tag.not.valid.on",
146                JavadocTagInfo.INHERIT_DOC.getText());
147            return;
148        }
149
150        if (this.mJavaFiveCompatibility) {
151            final DetailAST defOrNew = aAST.getParent().getParent();
152
153            if (defOrNew.branchContains(TokenTypes.EXTENDS_CLAUSE)
154                || defOrNew.branchContains(TokenTypes.IMPLEMENTS_CLAUSE)
155                || defOrNew.getType() == TokenTypes.LITERAL_NEW)
156            {
157                return;
158            }
159        }
160
161        if (containsTag
162            && (!AnnotationUtility.containsAnnotation(aAST, OVERRIDE)
163            && !AnnotationUtility.containsAnnotation(aAST, FQ_OVERRIDE)))
164        {
165            this.log(aAST.getLineNo(), "annotation.missing.override");
166        }
167    }
168
169    /**
170     * Checks to see if the text block contains a inheritDoc tag.
171     *
172     * @param aJavadoc the javadoc of the AST
173     * @return true if contains the tag
174     */
175    private boolean containsJavadocTag(final TextBlock aJavadoc)
176    {
177        if (aJavadoc == null) {
178            return false;
179        }
180
181        final String[] lines = aJavadoc.getText();
182
183        for (final String line : lines) {
184            final Matcher matchInheritDoc =
185                MissingOverrideCheck.MATCH_INHERITDOC.matcher(line);
186
187            if (matchInheritDoc.find()) {
188                return true;
189            }
190        }
191        return false;
192    }
193}