code: ///////////////////////////////////////////////////////////////////////////////////////////////
  // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
  // Copyright (C) 2001-2023 the original author or authors.
  //
  // This library is free software; you can redistribute it and/or
  // modify it under the terms of the GNU Lesser General Public
  // License as published by the Free Software Foundation; either
  // version 2.1 of the License, or (at your option) any later version.
  //
  // This library is distributed in the hope that it will be useful,
  // but WITHOUT ANY WARRANTY; without even the implied warranty of
  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  // Lesser General Public License for more details.
  //
  // You should have received a copy of the GNU Lesser General Public
  // License along with this library; if not, write to the Free Software
  // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  ///////////////////////////////////////////////////////////////////////////////////////////////
  
  package com.puppycrawl.tools.checkstyle.filefilters;
  
  import java.util.regex.Pattern;
  
  import com.puppycrawl.tools.checkstyle.AbstractAutomaticBean;
  import com.puppycrawl.tools.checkstyle.api.BeforeExecutionFileFilter;
  
  /**
   * <p>
   * File filter {@code BeforeExecutionExclusionFileFilter} decides which files should be
   * excluded from being processed by the utility.
   * </p>
   *
   * <p>
   * By default, Checkstyle includes all files and subdirectories in a directory to be processed and
   * checked for violations. Users could have files that are in these subdirectories that shouldn't
   * be processed with their checkstyle configuration for various reasons, one of which is a valid
   * Java file that won't pass Checkstyle's parser. When Checkstyle tries to parse a Java file and
   * fails, it will throw an {@code Exception} and halt parsing any more files for violations.
   * An example of a valid Java file Checkstyle can't parse is JDK 9's {@code module-info.java}.
   * This file filter will exclude these problem files from being parsed, allowing the rest of the
   * files to run normal and be validated.
   * </p>
   *
   * <p>
   * <b>Note:</b> When a file is excluded from the utility, it is excluded from all Checks and no
   * testing for violations will be performed on them.
   * </p>
   * <ul>
   * <li>
   * Property {@code fileNamePattern} - Define regular expression to match the file name against.
   * Type is {@code java.util.regex.Pattern}.
   * Default value is {@code null}.</li>
   * </ul>
   *
   * <p>
   * To configure the filter to exclude all 'module-info.java' files:
   * </p>
   *
   * <pre>
   * &lt;module name=&quot;BeforeExecutionExclusionFileFilter&quot;&gt;
   *   &lt;property name=&quot;fileNamePattern&quot; value=&quot;module\-info\.java$&quot;/&gt;
   * &lt;/module&gt;
   * </pre>
   * <p>
   * To configure the filter to run only on required files for example that ends with "Remote"
   * or end with "Client" in names or named as "Remote.java" or "Client.java"
   * use <a href="https://www.regular-expressions.info/lookaround.html">negative lookahead</a>:
   * </p>
   *
   * <pre>
   * &lt;module name=&quot;BeforeExecutionExclusionFileFilter&quot;&gt;
   *   &lt;property name=&quot;fileNamePattern&quot;
   *  value=&quot;^(?!.*(Remote\.java|Client\.java|[\\/]Remote\.java|[\\/]Client\.java)).*$&quot;/&gt;
   * &lt;/module&gt;
   * </pre>
   * <p>
   * To configure the filter to exclude all Test folder files:
   * </p>
   *
   * <pre>
   * &lt;module name=&quot;BeforeExecutionExclusionFileFilter&quot;&gt;
   *   &lt;property name=&quot;fileNamePattern&quot;
   *     value=&quot;.*[\\/]src[\\/]test[\\/].*$&quot;/&gt;
   * &lt;/module&gt;
   * </pre>
   * <p>
   * Parent is {@code com.puppycrawl.tools.checkstyle.Checker}
   * </p>
   *
   * @since 7.2
   */
  public final class BeforeExecutionExclusionFileFilter extends AbstractAutomaticBean
          implements BeforeExecutionFileFilter {
  
      /** Define regular expression to match the file name against. */
      private Pattern fileNamePattern;
  
      /**
       * Setter to define regular expression to match the file name against.
       *
       * @param fileNamePattern regular expression of the excluded file.
       */
      public void setFileNamePattern(Pattern fileNamePattern) {
          this.fileNamePattern = fileNamePattern;
      }
  
      @Override
      protected void finishLocalSetup() {
          // No code by default
      }
  
      @Override
      public boolean accept(String uri) {
          return fileNamePattern == null || !fileNamePattern.matcher(uri).find();
      }
  
  }
  