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 @Override
71 public int[] getDefaultTokens() {
72 return getRequiredTokens();
73 }
74
75 @Override
76 public int[] getAcceptableTokens() {
77 return getRequiredTokens();
78 }
79
80 @Override
81 public int[] getRequiredTokens() {
82 return new int[] {
83 TokenTypes.CLASS_DEF,
84 TokenTypes.INTERFACE_DEF,
85 TokenTypes.ENUM_DEF,
86 TokenTypes.ANNOTATION_DEF,
87 TokenTypes.RECORD_DEF,
88 };
89 }
90
91 @Override
92 public void beginTree(DetailAST rootAST) {
93 fileName = getSourceFileName();
94 seenFirstToken = false;
95 hasPublic = false;
96 wrongType = null;
97 isCompactSourceFile = rootAST != null
98 && rootAST.getType() == TokenTypes.COMPACT_COMPILATION_UNIT;
99 }
100
101 @Override
102 public void visitToken(DetailAST ast) {
103 if (!isCompactSourceFile) {
104 if (seenFirstToken) {
105 final DetailAST modifiers = ast.findFirstToken(TokenTypes.MODIFIERS);
106 if (modifiers.findFirstToken(TokenTypes.LITERAL_PUBLIC) != null
107 && TokenUtil.isRootNode(ast.getParent())) {
108 hasPublic = true;
109 }
110 }
111 else {
112 final String outerTypeName = TokenUtil.getIdent(ast).getText();
113
114 if (!fileName.equals(outerTypeName)) {
115 wrongType = ast;
116 }
117 }
118 seenFirstToken = true;
119 }
120 }
121
122 @Override
123 public void finishTree(DetailAST rootAST) {
124 if (!hasPublic && wrongType != null) {
125 log(wrongType, MSG_KEY);
126 }
127 }
128
129 /**
130 * Get source file name.
131 *
132 * @return source file name.
133 */
134 private String getSourceFileName() {
135 String name = getFilePath();
136 name = name.substring(name.lastIndexOf(File.separatorChar) + 1);
137 return FILE_EXTENSION_PATTERN.matcher(name).replaceAll("");
138 }
139
140 }