1 ///////////////////////////////////////////////////////////////////////////////////////////////
2 // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
3 // Copyright (C) 2001-2024 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 * <p>
28 * Checks that method names conform to a specified pattern.
29 * </p>
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 * <ul>
40 * <li>
41 * Property {@code allowClassName} - Control whether to allow a method name to have the same name
42 * as the enclosing class name. Setting this property {@code false} helps to avoid
43 * confusion between constructors and methods.
44 * Type is {@code boolean}.
45 * Default value is {@code false}.
46 * </li>
47 * <li>
48 * Property {@code applyToPackage} - Control if check should apply to package-private members.
49 * Type is {@code boolean}.
50 * Default value is {@code true}.
51 * </li>
52 * <li>
53 * Property {@code applyToPrivate} - Control if check should apply to private members.
54 * Type is {@code boolean}.
55 * Default value is {@code true}.
56 * </li>
57 * <li>
58 * Property {@code applyToProtected} - Control if check should apply to protected members.
59 * Type is {@code boolean}.
60 * Default value is {@code true}.
61 * </li>
62 * <li>
63 * Property {@code applyToPublic} - Control if check should apply to public members.
64 * Type is {@code boolean}.
65 * Default value is {@code true}.
66 * </li>
67 * <li>
68 * Property {@code format} - Sets the pattern to match valid identifiers.
69 * Type is {@code java.util.regex.Pattern}.
70 * Default value is {@code "^[a-z][a-zA-Z0-9]*$"}.
71 * </li>
72 * </ul>
73 * <p>
74 * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
75 * </p>
76 * <p>
77 * Violation Message Keys:
78 * </p>
79 * <ul>
80 * <li>
81 * {@code method.name.equals.class.name}
82 * </li>
83 * <li>
84 * {@code name.invalidPattern}
85 * </li>
86 * </ul>
87 *
88 * @since 3.0
89 */
90 public class MethodNameCheck
91 extends AbstractAccessControlNameCheck {
92
93 /**
94 * A key is pointing to the warning message text in "messages.properties"
95 * file.
96 */
97 public static final String MSG_KEY = "method.name.equals.class.name";
98
99 /**
100 * Control whether to allow a method name to have the same name as the enclosing class name.
101 * Setting this property {@code false} helps to avoid confusion
102 * between constructors and methods.
103 */
104 private boolean allowClassName;
105
106 /** Creates a new {@code MethodNameCheck} instance. */
107 public MethodNameCheck() {
108 super("^[a-z][a-zA-Z0-9]*$");
109 }
110
111 @Override
112 public int[] getDefaultTokens() {
113 return getRequiredTokens();
114 }
115
116 @Override
117 public int[] getAcceptableTokens() {
118 return getRequiredTokens();
119 }
120
121 @Override
122 public int[] getRequiredTokens() {
123 return new int[] {TokenTypes.METHOD_DEF, };
124 }
125
126 @Override
127 public void visitToken(DetailAST ast) {
128 if (!AnnotationUtil.hasOverrideAnnotation(ast)) {
129 // Will check the name against the format.
130 super.visitToken(ast);
131 }
132
133 if (!allowClassName) {
134 final DetailAST method =
135 ast.findFirstToken(TokenTypes.IDENT);
136 // in all cases this will be the classDef type except anon inner
137 // with anon inner classes this will be the Literal_New keyword
138 final DetailAST classDefOrNew = ast.getParent().getParent();
139 final DetailAST classIdent =
140 classDefOrNew.findFirstToken(TokenTypes.IDENT);
141 // Following logic is to handle when a classIdent can not be
142 // found. This is when you have a Literal_New keyword followed
143 // a DOT, which is when you have:
144 // new Outclass.InnerInterface(x) { ... }
145 // Such a rare case, will not have the logic to handle parsing
146 // down the tree looking for the first ident.
147 if (classIdent != null
148 && method.getText().equals(classIdent.getText())) {
149 log(method, MSG_KEY, method.getText());
150 }
151 }
152 }
153
154 /**
155 * Setter to control whether to allow a method name to have the same name
156 * as the enclosing class name. Setting this property {@code false}
157 * helps to avoid confusion between constructors and methods.
158 *
159 * @param allowClassName true to allow false to disallow
160 * @since 5.0
161 */
162 public void setAllowClassName(boolean allowClassName) {
163 this.allowClassName = allowClassName;
164 }
165
166 }