1 ///////////////////////////////////////////////////////////////////////////////////////////////
2 // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
3 // Copyright (C) 2001-2025 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 * Control whether to allow a method name to have the same name as the enclosing class name.
52 * Setting this property {@code false} helps to avoid confusion
53 * between constructors and methods.
54 */
55 private boolean allowClassName;
56
57 /** Creates a new {@code MethodNameCheck} instance. */
58 public MethodNameCheck() {
59 super("^[a-z][a-zA-Z0-9]*$");
60 }
61
62 @Override
63 public int[] getDefaultTokens() {
64 return getRequiredTokens();
65 }
66
67 @Override
68 public int[] getAcceptableTokens() {
69 return getRequiredTokens();
70 }
71
72 @Override
73 public int[] getRequiredTokens() {
74 return new int[] {TokenTypes.METHOD_DEF, };
75 }
76
77 /**
78 * Setter to control if check should apply to package-private members.
79 *
80 * @param applyTo new value of the property.
81 * @propertySince 5.1
82 */
83 @Override
84 public final void setApplyToPackage(boolean applyTo) {
85 super.setApplyToPackage(applyTo);
86 }
87
88 /**
89 * Setter to control if check should apply to private members.
90 *
91 * @param applyTo new value of the property.
92 * @propertySince 5.1
93 */
94 @Override
95 public final void setApplyToPrivate(boolean applyTo) {
96 super.setApplyToPrivate(applyTo);
97 }
98
99 /**
100 * Setter to control if check should apply to protected members.
101 *
102 * @param applyTo new value of the property.
103 * @propertySince 5.1
104 */
105 @Override
106 public final void setApplyToProtected(boolean applyTo) {
107 super.setApplyToProtected(applyTo);
108 }
109
110 /**
111 * Setter to control if check should apply to public members.
112 *
113 * @param applyTo new value of the property.
114 * @propertySince 5.1
115 */
116 @Override
117 public final void setApplyToPublic(boolean applyTo) {
118 super.setApplyToPublic(applyTo);
119 }
120
121 @Override
122 public void visitToken(DetailAST ast) {
123 if (!AnnotationUtil.hasOverrideAnnotation(ast)) {
124 // Will check the name against the format.
125 super.visitToken(ast);
126 }
127
128 if (!allowClassName) {
129 final DetailAST method =
130 ast.findFirstToken(TokenTypes.IDENT);
131 // in all cases this will be the classDef type except anon inner
132 // with anon inner classes this will be the Literal_New keyword
133 final DetailAST classDefOrNew = ast.getParent().getParent();
134 final DetailAST classIdent =
135 classDefOrNew.findFirstToken(TokenTypes.IDENT);
136 // Following logic is to handle when a classIdent can not be
137 // found. This is when you have a Literal_New keyword followed
138 // a DOT, which is when you have:
139 // new Outclass.InnerInterface(x) { ... }
140 // Such a rare case, will not have the logic to handle parsing
141 // down the tree looking for the first ident.
142 if (classIdent != null
143 && method.getText().equals(classIdent.getText())) {
144 log(method, MSG_KEY, method.getText());
145 }
146 }
147 }
148
149 /**
150 * Setter to control whether to allow a method name to have the same name
151 * as the enclosing class name. Setting this property {@code false}
152 * helps to avoid confusion between constructors and methods.
153 *
154 * @param allowClassName true to allow false to disallow
155 * @since 5.0
156 */
157 public void setAllowClassName(boolean allowClassName) {
158 this.allowClassName = allowClassName;
159 }
160
161 }