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1   ////////////////////////////////////////////////////////////////////////////////
2   // checkstyle: Checks Java source code for adherence to a set of rules.
3   // Copyright (C) 2001-2017 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.filefilters;
21  
22  import java.util.regex.Pattern;
23  
24  import com.puppycrawl.tools.checkstyle.api.AutomaticBean;
25  import com.puppycrawl.tools.checkstyle.api.BeforeExecutionFileFilter;
26  
27  /**
28   * <p>
29   * File filter {@code BeforeExecutionExclusionFileFilter} decides which files should be
30   * excluded from being processed by the utility.
31   * </p>
32   *
33   * <p>
34   * By default Checkstyle includes all files and sub-directories in a directory to be processed and
35   * checked for violations. Users could have files that are in these sub-directories that shouldn't
36   * be processed with their checkstyle configuration for various reasons, one of which is a valid
37   * Java file that won't pass Checkstyle's parser. When Checkstyle tries to parse a Java file and
38   * fails, it will throw an {@code Exception} and halt parsing any more files for violations.
39   * An example of a valid Java file Checkstyle can't parse is JDK 9's {@code module-info.java}.
40   * This file filter will exclude these problem files from being parsed, allowing the rest of the
41   * files to run normal and be validated.
42   * </p>
43   *
44   * <p>
45   * <b>Note:</b> When a file is excluded from the utility, it is excluded from all Checks and no
46   * testing for violations will be performed on them.
47   * </p>
48   *
49   * <p>
50   * Check have following options:
51   * </p>
52   * <ul>
53   * <li>
54   * fileNamePattern - Regular expression to match the file name against. Default value is null.</li>
55   * </ul>
56   * <br>
57   *
58   * <p>
59   * To configure the filter to exclude all 'module-info.java' files:
60   * </p>
61   *
62   * <pre>
63   * &lt;module name=&quot;BeforeExecutionExclusionFileFilter&quot;&gt;
64   *   &lt;property name=&quot;fileNamePattern&quot; value=&quot;module\-info\.java$&quot;/&gt;
65   * &lt;/module&gt;
66   * </pre>
67   *
68   * @author Richard Veach
69   */
70  public final class BeforeExecutionExclusionFileFilter extends AutomaticBean
71          implements BeforeExecutionFileFilter {
72  
73      /** Filename of exclusion. */
74      private Pattern fileNamePattern;
75  
76      /**
77       * Sets regular expression of the file to exclude.
78       *
79       * @param fileNamePattern regular expression of the excluded file.
80       */
81      public void setFileNamePattern(Pattern fileNamePattern) {
82          this.fileNamePattern = fileNamePattern;
83      }
84  
85      @Override
86      protected void finishLocalSetup() {
87          // No code by default
88      }
89  
90      @Override
91      public boolean accept(String uri) {
92          return fileNamePattern == null || !fileNamePattern.matcher(uri).find();
93      }
94  }