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.sizes;
  
  import java.io.File;
  
  import com.puppycrawl.tools.checkstyle.StatelessCheck;
  import com.puppycrawl.tools.checkstyle.api.AbstractFileSetCheck;
  import com.puppycrawl.tools.checkstyle.api.FileText;
  
  /**
   * <p>
   * Checks for long source files.
   * </p>
   * <p>
   * Rationale: If a source file becomes very long it is hard to understand.
   * Therefore, long classes should usually be refactored into several
   * individual classes that focus on a specific task.
   * </p>
   * <ul>
   * <li>
   * Property {@code max} - Specify the maximum number of lines allowed.
   * Type is {@code int}.
   * Default value is {@code 2000}.
   * </li>
   * <li>
   * Property {@code fileExtensions} - Specify the file type extension of files to process.
   * Type is {@code java.lang.String[]}.
   * Default value is {@code ""}.
   * </li>
   * </ul>
   * <p>
   * To configure the check:
   * </p>
   * <pre>
   * &lt;module name="FileLength"/&gt;
   * </pre>
   * <p>
   * To configure the check to accept files with up to 1500 lines:
   * </p>
   * <pre>
   * &lt;module name="FileLength"&gt;
   *   &lt;property name="max" value="1500"/&gt;
   * &lt;/module&gt;
   * </pre>
   * <p>
   * Parent is {@code com.puppycrawl.tools.checkstyle.Checker}
   * </p>
   * <p>
   * Violation Message Keys:
   * </p>
   * <ul>
   * <li>
   * {@code maxLen.file}
   * </li>
   * </ul>
   *
   * @since 5.0
   */
  @StatelessCheck
  public class FileLengthCheck extends AbstractFileSetCheck {
  
      /**
       * A key is pointing to the warning message text in "messages.properties"
       * file.
       */
      public static final String MSG_KEY = "maxLen.file";
  
      /** Default maximum number of lines. */
      private static final int DEFAULT_MAX_LINES = 2000;
  
      /** Specify the maximum number of lines allowed. */
      private int max = DEFAULT_MAX_LINES;
  
      @Override
      protected void processFiltered(File file, FileText fileText) {
          if (fileText.size() > max) {
              log(1, MSG_KEY, fileText.size(), max);
          }
      }
  
      /**
       * Setter to specify the maximum number of lines allowed.
       *
       * @param length the maximum length of a Java source file
       */
      public void setMax(int length) {
          max = length;
      }
  
  }
  