1 ///////////////////////////////////////////////////////////////////////////////////////////////
2 // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
3 // Copyright (C) 2001-2026 the original author or authors.
4 //
5 // This library is free software; you can redistribute it and/or
6 // modify it under the terms of the GNU Lesser General Public
7 // License as published by the Free Software Foundation; either
8 // version 2.1 of the License, or (at your option) any later version.
9 //
10 // This library is distributed in the hope that it will be useful,
11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 // Lesser General Public License for more details.
14 //
15 // You should have received a copy of the GNU Lesser General Public
16 // License along with this library; if not, write to the Free Software
17 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 ///////////////////////////////////////////////////////////////////////////////////////////////
19
20 package com.puppycrawl.tools.checkstyle.checks.naming;
21
22 import com.puppycrawl.tools.checkstyle.api.DetailAST;
23 import com.puppycrawl.tools.checkstyle.api.TokenTypes;
24 import com.puppycrawl.tools.checkstyle.utils.AnnotationUtil;
25
26 /**
27 * <div>
28 * Checks that method names conform to a specified pattern.
29 * </div>
30 *
31 * <p>Also, checks if a method name has the same name as the residing class.
32 * The default is false (it is not allowed). It is legal in Java to have
33 * method with the same name as a class. As long as a return type is specified
34 * it is a method and not a constructor which it could be easily confused as.
35 * Does not check-style the name of an overridden methods because the developer does not
36 * have a choice in renaming such methods.
37 * </p>
38 *
39 * @since 3.0
40 */
41 public class MethodNameCheck
42 extends AbstractAccessControlNameCheck {
43
44 /**
45 * A key is pointing to the warning message text in "messages.properties"
46 * file.
47 */
48 public static final String MSG_KEY = "method.name.equals.class.name";
49
50 /**
51 * A key is pointing to the warning message text in "messages.properties"
52 * file.
53 */
54 public static final String MSG_INVALID_PATTERN = "name.invalidPattern";
55
56 /**
57 * Control whether to allow a method name to have the same name as the enclosing class name.
58 * Setting this property {@code false} helps to avoid confusion
59 * between constructors and methods.
60 */
61 private boolean allowClassName;
62
63 /** Creates a new {@code MethodNameCheck} instance. */
64 public MethodNameCheck() {
65 super("^[a-z][a-zA-Z0-9]*$", MSG_INVALID_PATTERN);
66 }
67
68 @Override
69 public int[] getDefaultTokens() {
70 return getRequiredTokens();
71 }
72
73 @Override
74 public int[] getAcceptableTokens() {
75 return getRequiredTokens();
76 }
77
78 @Override
79 public int[] getRequiredTokens() {
80 return new int[] {TokenTypes.METHOD_DEF, };
81 }
82
83 /**
84 * Setter to control if check should apply to package-private members.
85 *
86 * @param applyTo new value of the property.
87 * @propertySince 5.1
88 */
89 @Override
90 public final void setApplyToPackage(boolean applyTo) {
91 super.setApplyToPackage(applyTo);
92 }
93
94 /**
95 * Setter to control if check should apply to private members.
96 *
97 * @param applyTo new value of the property.
98 * @propertySince 5.1
99 */
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 }