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;
21
22 import java.io.File;
23 import java.util.regex.Pattern;
24
25 import com.puppycrawl.tools.checkstyle.FileStatefulCheck;
26 import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
27 import com.puppycrawl.tools.checkstyle.api.DetailAST;
28 import com.puppycrawl.tools.checkstyle.api.TokenTypes;
29 import com.puppycrawl.tools.checkstyle.utils.TokenUtil;
30
31 /**
32 * <div>
33 * Checks that the outer type name and the file name match.
34 * For example, the class {@code Foo} must be in a file named {@code Foo.java}.
35 * </div>
36 *
37 * @since 5.3
38 */
39 @FileStatefulCheck
40 public class OuterTypeFilenameCheck extends AbstractCheck {
41
42 /**
43 * A key is pointing to the warning message text in "messages.properties"
44 * file.
45 */
46 public static final String MSG_KEY = "type.file.mismatch";
47
48 /** Pattern matching any file extension with dot included. */
49 private static final Pattern FILE_EXTENSION_PATTERN = Pattern.compile("\\.[^.]*$");
50
51 /** Indicates whether the first token has been seen in the file. */
52 private boolean seenFirstToken;
53
54 /** Current file name. */
55 private String fileName;
56
57 /** If file has public type. */
58 private boolean hasPublic;
59
60 /** Outer type with mismatched file name. */
61 private DetailAST wrongType;
62
63 /**
64 * Indicates whether the file is a compact source file. Its outer type is an
65 * implicit unnamed class that is not declared with a name in the source, so
66 * there is no type name to compare against the file name.
67 */
68 private boolean isCompactSourceFile;
69
70 /**
71 * Creates a new {@code OuterTypeFilenameCheck} instance.
72 */
73 public OuterTypeFilenameCheck() {
74 // no code by default
75 }
76
77 @Override
78 public int[] getDefaultTokens() {
79 return getRequiredTokens();
80 }
81
82 @Override
83 public int[] getAcceptableTokens() {
84 return getRequiredTokens();
85 }
86
87 @Override
88 public int[] getRequiredTokens() {
89 return new int[] {
90 TokenTypes.CLASS_DEF,
91 TokenTypes.INTERFACE_DEF,
92 TokenTypes.ENUM_DEF,
93 TokenTypes.ANNOTATION_DEF,
94 TokenTypes.RECORD_DEF,
95 };
96 }
97
98 @Override
99 public void beginTree(DetailAST rootAST) {
100 fileName = getSourceFileName();
101 seenFirstToken = false;
102 hasPublic = false;
103 wrongType = null;
104 isCompactSourceFile = rootAST != null
105 && rootAST.getType() == TokenTypes.COMPACT_COMPILATION_UNIT;
106 }
107
108 @Override
109 public void visitToken(DetailAST ast) {
110 if (!isCompactSourceFile) {
111 if (seenFirstToken) {
112 final DetailAST modifiers = ast.findFirstToken(TokenTypes.MODIFIERS);
113 if (modifiers.findFirstToken(TokenTypes.LITERAL_PUBLIC) != null
114 && TokenUtil.isRootNode(ast.getParent())) {
115 hasPublic = true;
116 }
117 }
118 else {
119 final String outerTypeName = TokenUtil.getIdent(ast).getText();
120
121 if (!fileName.equals(outerTypeName)) {
122 wrongType = ast;
123 }
124 }
125 seenFirstToken = true;
126 }
127 }
128
129 @Override
130 public void finishTree(DetailAST rootAST) {
131 if (!hasPublic && wrongType != null) {
132 log(wrongType, MSG_KEY);
133 }
134 }
135
136 /**
137 * Get source file name.
138 *
139 * @return source file name.
140 */
141 private String getSourceFileName() {
142 String name = getFilePath();
143 name = name.substring(name.lastIndexOf(File.separatorChar) + 1);
144 return FILE_EXTENSION_PATTERN.matcher(name).replaceAll("");
145 }
146
147 }