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.imports;
21
22 import java.util.regex.Pattern;
23
24 /**
25 * Represents an import rules for a specific file. Only the file name is
26 * considered and only files processed by TreeWalker. The file's
27 * extension is ignored.
28 */
29 class FileImportControl extends AbstractImportControl {
30
31 /** The name for the file. */
32 private final String name;
33 /** The regex pattern for exact matches - only not null if regex is true. */
34 private final Pattern patternForExactMatch;
35 /** If this file name represents a regular expression. */
36 private final boolean regex;
37
38 /**
39 * Construct a file node.
40 *
41 * @param parent the parent node.
42 * @param name the name of the file.
43 * @param regex flags interpretation of name as regex pattern.
44 */
45 /* package */ FileImportControl(PkgImportControl parent, String name, boolean regex) {
46 super(parent, MismatchStrategy.DELEGATE_TO_PARENT);
47 this.regex = regex;
48 this.name = name;
49 patternForExactMatch = createPatternForExactMatch(name);
50 }
51
52 /**
53 * Creates a Pattern from {@code expression}.
54 *
55 * @param expression a self-contained regular expression matching the full
56 * file name exactly.
57 * @return a Pattern.
58 */
59 private static Pattern createPatternForExactMatch(String expression) {
60 return Pattern.compile(expression);
61 }
62
63 @Override
64 public AbstractImportControl locateFinest(String forPkg, String forFileName) {
65 AbstractImportControl finestMatch = null;
66 // Check if we are a match.
67 if (matchesExactly(forPkg, forFileName)) {
68 finestMatch = this;
69 }
70 return finestMatch;
71 }
72
73 @Override
74 protected boolean matchesExactly(String pkg, String fileName) {
75 final boolean result;
76 if (fileName == null) {
77 result = false;
78 }
79 else if (regex) {
80 result = patternForExactMatch.matcher(fileName).matches();
81 }
82 else {
83 result = name.equals(fileName);
84 }
85 return result;
86 }
87
88 }