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.naming;
021
022import com.puppycrawl.tools.checkstyle.api.DetailAST;
023import com.puppycrawl.tools.checkstyle.api.TokenTypes;
024import com.puppycrawl.tools.checkstyle.utils.AnnotationUtil;
025
026/**
027 * <div>
028 * Checks that method names conform to a specified pattern.
029 * </div>
030 *
031 * <p>Also, checks if a method name has the same name as the residing class.
032 * The default is false (it is not allowed). It is legal in Java to have
033 * method with the same name as a class. As long as a return type is specified
034 * it is a method and not a constructor which it could be easily confused as.
035 * Does not check-style the name of an overridden methods because the developer does not
036 * have a choice in renaming such methods.
037 * </p>
038 *
039 * @since 3.0
040 */
041public class MethodNameCheck
042    extends AbstractAccessControlNameCheck {
043
044    /**
045     * A key is pointing to the warning message text in "messages.properties"
046     * file.
047     */
048    public static final String MSG_KEY = "method.name.equals.class.name";
049
050    /**
051     * A key is pointing to the warning message text in "messages.properties"
052     * file.
053     */
054    public static final String MSG_INVALID_PATTERN = "name.invalidPattern";
055
056    /**
057     * Control whether to allow a method name to have the same name as the enclosing class name.
058     * Setting this property {@code false} helps to avoid confusion
059     * between constructors and methods.
060     */
061    private boolean allowClassName;
062
063    /** Creates a new {@code MethodNameCheck} instance. */
064    public MethodNameCheck() {
065        super("^[a-z][a-zA-Z0-9]*$", MSG_INVALID_PATTERN);
066    }
067
068    @Override
069    public int[] getDefaultTokens() {
070        return getRequiredTokens();
071    }
072
073    @Override
074    public int[] getAcceptableTokens() {
075        return getRequiredTokens();
076    }
077
078    @Override
079    public int[] getRequiredTokens() {
080        return new int[] {TokenTypes.METHOD_DEF, };
081    }
082
083    /**
084     * Setter to control if check should apply to package-private members.
085     *
086     * @param applyTo new value of the property.
087     * @propertySince 5.1
088     */
089    @Override
090    public final void setApplyToPackage(boolean applyTo) {
091        super.setApplyToPackage(applyTo);
092    }
093
094    /**
095     * Setter to control if check should apply to private members.
096     *
097     * @param applyTo new value of the property.
098     * @propertySince 5.1
099     */
100    @Override
101    public final void setApplyToPrivate(boolean applyTo) {
102        super.setApplyToPrivate(applyTo);
103    }
104
105    /**
106     * Setter to control if check should apply to protected members.
107     *
108     * @param applyTo new value of the property.
109     * @propertySince 5.1
110     */
111    @Override
112    public final void setApplyToProtected(boolean applyTo) {
113        super.setApplyToProtected(applyTo);
114    }
115
116    /**
117     * Setter to control if check should apply to public members.
118     *
119     * @param applyTo new value of the property.
120     * @propertySince 5.1
121     */
122    @Override
123    public final void setApplyToPublic(boolean applyTo) {
124        super.setApplyToPublic(applyTo);
125    }
126
127    @Override
128    public void visitToken(DetailAST ast) {
129        if (!AnnotationUtil.hasOverrideAnnotation(ast)) {
130            // Will check the name against the format.
131            super.visitToken(ast);
132        }
133
134        if (!allowClassName) {
135            // in all cases this will be the classDef type except anon inner
136            // with anon inner classes this will be the Literal_New keyword
137            final DetailAST classDefOrNew = ast.getParent().getParent();
138
139            if (classDefOrNew != null) {
140                final DetailAST method = ast.findFirstToken(TokenTypes.IDENT);
141                final DetailAST classIdent =
142                    classDefOrNew.findFirstToken(TokenTypes.IDENT);
143                // Following logic is to handle when a classIdent can not be
144                // found. This is when you have a Literal_New keyword followed
145                // a DOT, which is when you have:
146                // new Outclass.InnerInterface(x) { ... }
147                // Such a rare case, will not have the logic to handle parsing
148                // down the tree looking for the first ident.
149                if (classIdent != null
150                    && method.getText().equals(classIdent.getText())) {
151                    log(method, MSG_KEY, method.getText());
152                }
153            }
154        }
155    }
156
157    /**
158     * Setter to control whether to allow a method name to have the same name
159     * as the enclosing class name. Setting this property {@code false}
160     * helps to avoid confusion between constructors and methods.
161     *
162     * @param allowClassName true to allow false to disallow
163     * @since 5.0
164     */
165    public void setAllowClassName(boolean allowClassName) {
166        this.allowClassName = allowClassName;
167    }
168
169}