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;
  
  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 the style of array type definitions.
   * Some like Java style: {@code public static void main(String[] args)}
   * and some like C style: {@code public static void main(String args[])}.
   * </p>
   * <p>
   * By default, the Check enforces Java style.
   * </p>
   * <p>
   * This check strictly enforces only Java style for method return types regardless
   * of the value for 'javaStyle'. For example, {@code byte[] getData()}.
   * This is because C doesn't compile methods with array declarations on the name.
   * </p>
   * <ul>
   * <li>
   * Property {@code javaStyle} - Control whether to enforce Java style (true) or C style (false).
   * Type is {@code boolean}.
   * Default value is {@code true}.
   * </li>
   * </ul>
   * <p>
   * To configure the check to enforce Java style:
   * </p>
   * <pre>
   * &lt;module name="ArrayTypeStyle"/&gt;
   * </pre>
   * <p>
   * Example:
   * </p>
   * <pre>
   * public class MyClass {
   *   int[] nums; // OK
   *   String strings[]; // violation
   *
   *   char[] toCharArray() { // OK
   *     return null;
   *   }
   *
   *   byte getData()[] { // violation
   *     return null;
   *   }
   * }
   * </pre>
   * <p>
   * To configure the check to enforce C style:
   * </p>
   * <pre>
   * &lt;module name="ArrayTypeStyle"&gt;
   *   &lt;property name="javaStyle" value="false"/&gt;
   * &lt;/module&gt;
   * </pre>
   * <p>
   * Example:
   * </p>
   * <pre>
   * public class MyClass {
   *   int[] nums; // violation
   *   String strings[]; // OK
   *
   *   char[] toCharArray() { // OK
   *     return null;
   *   }
   *
   *   byte getData()[] { // violation
   *     return null;
   *   }
   * }
   * </pre>
   * <p>
   * Parent is {@code com.puppycrawl.tools.checkstyle.TreeWalker}
   * </p>
   * <p>
   * Violation Message Keys:
   * </p>
   * <ul>
   * <li>
   * {@code array.type.style}
   * </li>
   * </ul>
   *
   * @since 3.1
   */
  @StatelessCheck
  public class ArrayTypeStyleCheck extends AbstractCheck {
  
      /**
       * A key is pointing to the warning message text in "messages.properties"
       * file.
       */
      public static final String MSG_KEY = "array.type.style";
  
      /** Control whether to enforce Java style (true) or C style (false). */
      private boolean javaStyle = true;
  
      @Override
      public int[] getDefaultTokens() {
          return getRequiredTokens();
      }
  
      @Override
      public int[] getAcceptableTokens() {
          return getRequiredTokens();
      }
  
      @Override
      public int[] getRequiredTokens() {
          return new int[] {TokenTypes.ARRAY_DECLARATOR};
      }
  
      @Override
      public void visitToken(DetailAST ast) {
          final DetailAST typeAST = ast.getParent();
          final DetailAST identAst = typeAST.getNextSibling();
          // If identAst is null, we have a 'LITERAL_NEW' expression, i.e. 'new int[2][2]'
          if (identAst != null) {
              final boolean isMethod = typeAST.getParent().getType() == TokenTypes.METHOD_DEF;
              final boolean isJavaStyle = identAst.getLineNo() > ast.getLineNo()
                  || identAst.getColumnNo() - ast.getColumnNo() > -1;
  
              // force all methods to be Java style (see note in top Javadoc)
              final boolean isMethodViolation = isMethod && !isJavaStyle;
              final boolean isVariableViolation = !isMethod
                      && isJavaStyle != javaStyle;
  
              if (isMethodViolation || isVariableViolation) {
                  log(ast, MSG_KEY);
              }
          }
      }
  
      /**
       * Setter to control whether to enforce Java style (true) or C style (false).
       *
       * @param javaStyle true if Java style should be used.
       */
      public void setJavaStyle(boolean javaStyle) {
          this.javaStyle = javaStyle;
      }
  
  }
  