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.checks.imports;
  
  /**
   * Represents whether a class is allowed to be imported or not.
   */
  class ClassImportRule extends AbstractImportRule {
  
      /** Package to control access to. */
      private final String className;
  
      /**
       * Constructs an instance.
       *
       * @param allow whether to allow access.
       * @param localOnly whether the rule is to be applied locally only
       * @param className the class to apply the rule on.
       * @param regExp whether the class name is to be interpreted as a regular
       *        expression.
       */
      /* package */  ClassImportRule(final boolean allow, final boolean localOnly,
          final String className, final boolean regExp) {
          super(allow, localOnly, regExp);
          this.className = className;
      }
  
      /**
       * Verifies whether a class name is used.
       *
       * @param forImport the import to check.
       * @return a result {@link AccessResult} indicating whether it can be used.
       */
      @Override
      public AccessResult verifyImport(final String forImport) {
          final boolean classMatch;
  
          if (isRegExp()) {
              classMatch = forImport.matches(className);
          }
          else {
              classMatch = forImport.equals(className);
          }
  
          return calculateResult(classMatch);
      }
  
  }
  