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>
   * Checks that array initialization do not contain a trailing comma.
   * Rationale: JLS allows trailing commas in arrays and enumerations, but does not allow
   * them in other locations. To unify the coding style, the use of trailing commas should
   * be prohibited.
   * </p>
   * <pre>
   * int[] foo = new int[] {
   *   1,
   *   2
   * };
   * </pre>
   * <p>
   * The check demands that there should not be any comma after the last element of an array.
   * </p>
   * <pre>
   * String[] foo = new String[] {
   *   "FOO",
   *   "BAR", //violation
   * }
   * </pre>
   * <p>
   * To configure the check:
   * </p>
   * <pre>
   * &lt;module name=&quot;NoArrayTrailingComma&quot;/&gt;
   * </pre>
   * <p>
   * Which results in the following violations:
   * </p>
   * <pre>
   * String[] foo1 = {
   *   "FOO", // OK
   *   "BAR", // violation
   * };
   * String[] foo2 = { "FOO", "BAR", }; // violation
   * String[] foo3 = {
   *   "FOO", // OK
   *   "BAR" // OK
   * };
   * String[] foo4 = { "FOO", "BAR" }; // OK
   * </pre>
   * <p>
   * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
   * </p>
   * <p>
   * Violation Message Keys:
   * </p>
   * <ul>
   * <li>
   * {@code no.array.trailing.comma}
   * </li>
   * </ul>
   *
   * @since 8.28
   */
  @StatelessCheck
  public class NoArrayTrailingCommaCheck extends AbstractCheck {
  
      /**
       * A key is pointing to the warning message text in "messages.properties"
       * file.
       */
      public static final String MSG_KEY = "no.array.trailing.comma";
  
      @Override
      public int[] getDefaultTokens() {
          return getRequiredTokens();
      }
  
      @Override
      public int[] getAcceptableTokens() {
          return getRequiredTokens();
      }
  
      @Override
      public int[] getRequiredTokens() {
          return new int[] {TokenTypes.ARRAY_INIT};
      }
  
      @Override
      public void visitToken(DetailAST arrayInit) {
          final DetailAST rcurly = arrayInit.findFirstToken(TokenTypes.RCURLY);
          final DetailAST previousSibling = rcurly.getPreviousSibling();
          if (previousSibling != null && previousSibling.getType() == TokenTypes.COMMA) {
              log(previousSibling, MSG_KEY);
          }
      }
  }
  