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.coding;
  
  import com.puppycrawl.tools.checkstyle.StatelessCheck;
  import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
  import com.puppycrawl.tools.checkstyle.api.DetailAST;
  import com.puppycrawl.tools.checkstyle.api.TokenTypes;
  
  /**
   * <p>
   * Detects empty statements (standalone {@code ";"} semicolon).
   * Empty statements often introduce bugs that are hard to spot
   * </p>
   * <p>
   * To configure the check:
   * </p>
   * <pre>
   * &lt;module name=&quot;EmptyStatement&quot;/&gt;
   * </pre>
   * <p>
   * Example:
   * </p>
   * <pre>
   * public void foo() {
   *   int i = 5;
   *   if (i &gt; 3); // violation, ";" right after if statement
   *     i++;
   *   for (i = 0; i &lt; 5; i++); // violation
   *     i++;
   *   while (i &gt; 10) // OK
   *     i++;
   * }
   * </pre>
   * <p>
   * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
   * </p>
   * <p>
   * Violation Message Keys:
   * </p>
   * <ul>
   * <li>
   * {@code empty.statement}
   * </li>
   * </ul>
   *
   * @since 3.1
   */
  @StatelessCheck
  public class EmptyStatementCheck extends AbstractCheck {
  
      /**
       * A key is pointing to the warning message text in "messages.properties"
       * file.
       */
      public static final String MSG_KEY = "empty.statement";
  
      @Override
      public int[] getDefaultTokens() {
          return getRequiredTokens();
      }
  
      @Override
      public int[] getAcceptableTokens() {
          return getRequiredTokens();
      }
  
      @Override
      public int[] getRequiredTokens() {
          return new int[] {TokenTypes.EMPTY_STAT};
      }
  
      @Override
      public void visitToken(DetailAST ast) {
          log(ast, MSG_KEY);
      }
  
  }
  