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.indentation;
  
  import java.lang.reflect.Constructor;
  import java.util.HashMap;
  import java.util.Map;
  import java.util.Set;
  
  import com.puppycrawl.tools.checkstyle.api.DetailAST;
  import com.puppycrawl.tools.checkstyle.api.TokenTypes;
  import com.puppycrawl.tools.checkstyle.utils.CommonUtil;
  
  /**
   * Factory for handlers. Looks up constructor via reflection.
   *
   */
  public class HandlerFactory {
  
      /**
       * Registered handlers.
       */
      private final Map<Integer, Constructor<?>> typeHandlers = new HashMap<>();
  
      /** Cache for created method call handlers. */
      private final Map<DetailAST, AbstractExpressionHandler> createdHandlers = new HashMap<>();
  
      /**
       * Creates a HandlerFactory.
       *
       * @noinspection OverlyCoupledMethod
       * @noinspectionreason OverlyCoupledMethod - complex nature of indentation check
       *      requires this coupling
       */
      public HandlerFactory() {
          register(TokenTypes.CASE_GROUP, CaseHandler.class);
          register(TokenTypes.LITERAL_SWITCH, SwitchHandler.class);
          register(TokenTypes.SLIST, SlistHandler.class);
          register(TokenTypes.PACKAGE_DEF, PackageDefHandler.class);
          register(TokenTypes.LITERAL_ELSE, ElseHandler.class);
          register(TokenTypes.LITERAL_IF, IfHandler.class);
          register(TokenTypes.LITERAL_TRY, TryHandler.class);
          register(TokenTypes.LITERAL_CATCH, CatchHandler.class);
          register(TokenTypes.LITERAL_FINALLY, FinallyHandler.class);
          register(TokenTypes.LITERAL_DO, DoWhileHandler.class);
          register(TokenTypes.LITERAL_WHILE, WhileHandler.class);
          register(TokenTypes.LITERAL_FOR, ForHandler.class);
          register(TokenTypes.METHOD_DEF, MethodDefHandler.class);
          register(TokenTypes.CTOR_DEF, MethodDefHandler.class);
          register(TokenTypes.CLASS_DEF, ClassDefHandler.class);
          register(TokenTypes.ENUM_DEF, ClassDefHandler.class);
          register(TokenTypes.OBJBLOCK, ObjectBlockHandler.class);
          register(TokenTypes.INTERFACE_DEF, ClassDefHandler.class);
          register(TokenTypes.IMPORT, ImportHandler.class);
          register(TokenTypes.ARRAY_INIT, ArrayInitHandler.class);
          register(TokenTypes.ANNOTATION_ARRAY_INIT, AnnotationArrayInitHandler.class);
          register(TokenTypes.METHOD_CALL, MethodCallHandler.class);
          register(TokenTypes.CTOR_CALL, MethodCallHandler.class);
          register(TokenTypes.SUPER_CTOR_CALL, MethodCallHandler.class);
          register(TokenTypes.LABELED_STAT, LabelHandler.class);
          register(TokenTypes.STATIC_INIT, StaticInitHandler.class);
          register(TokenTypes.INSTANCE_INIT, SlistHandler.class);
          register(TokenTypes.VARIABLE_DEF, MemberDefHandler.class);
          register(TokenTypes.LITERAL_NEW, NewHandler.class);
          register(TokenTypes.INDEX_OP, IndexHandler.class);
          register(TokenTypes.LITERAL_SYNCHRONIZED, SynchronizedHandler.class);
          register(TokenTypes.LAMBDA, LambdaHandler.class);
          register(TokenTypes.ANNOTATION_DEF, ClassDefHandler.class);
          register(TokenTypes.ANNOTATION_FIELD_DEF, MethodDefHandler.class);
          register(TokenTypes.SWITCH_RULE, SwitchRuleHandler.class);
          register(TokenTypes.LITERAL_YIELD, YieldHandler.class);
          register(TokenTypes.RECORD_DEF, ClassDefHandler.class);
          register(TokenTypes.COMPACT_CTOR_DEF, MethodDefHandler.class);
      }
  
      /**
       * Registers a handler.
       *
       * @param <T> type of the handler class object.
       * @param type
       *                type from TokenTypes
       * @param handlerClass
       *                the handler to register
       */
      private <T> void register(int type, Class<T> handlerClass) {
          final Constructor<T> ctor = CommonUtil.getConstructor(handlerClass,
                  IndentationCheck.class,
                  // current AST
                  DetailAST.class,
                  // parent
                  AbstractExpressionHandler.class
          );
          typeHandlers.put(type, ctor);
      }
  
      /**
       * Returns true if this type (form TokenTypes) is handled.
       *
       * @param type type from TokenTypes
       * @return true if handler is registered, false otherwise
       */
      public boolean isHandledType(int type) {
          final Set<Integer> typeSet = typeHandlers.keySet();
          return typeSet.contains(type);
      }
  
      /**
       * Gets list of registered handler types.
       *
       * @return int[] of TokenType types
       */
      public int[] getHandledTypes() {
          final Set<Integer> typeSet = typeHandlers.keySet();
          final int[] types = new int[typeSet.size()];
          int index = 0;
          for (final Integer val : typeSet) {
              types[index] = val;
              index++;
          }
  
          return types;
      }
  
      /**
       * Get the handler for an AST.
       *
       * @param indentCheck   the indentation check
       * @param ast           ast to handle
       * @param parent        the handler parent of this AST
       *
       * @return the ExpressionHandler for ast
       */
      public AbstractExpressionHandler getHandler(IndentationCheck indentCheck,
          DetailAST ast, AbstractExpressionHandler parent) {
          final AbstractExpressionHandler resultHandler;
          final AbstractExpressionHandler handler =
              createdHandlers.get(ast);
          if (handler != null) {
              resultHandler = handler;
          }
          else if (ast.getType() == TokenTypes.METHOD_CALL) {
              resultHandler = createMethodCallHandler(indentCheck, ast, parent);
          }
          else {
              final Constructor<?> handlerCtor = typeHandlers.get(ast.getType());
              resultHandler = (AbstractExpressionHandler) CommonUtil.invokeConstructor(
                  handlerCtor, indentCheck, ast, parent);
          }
          return resultHandler;
      }
  
      /**
       * Create new instance of handler for METHOD_CALL.
       *
       * @param indentCheck   the indentation check
       * @param ast           ast to handle
       * @param parent        the handler parent of this AST
       *
       * @return new instance.
       */
      private AbstractExpressionHandler createMethodCallHandler(IndentationCheck indentCheck,
          DetailAST ast, AbstractExpressionHandler parent) {
          DetailAST astNode = ast.getFirstChild();
          while (astNode.getType() == TokenTypes.DOT) {
              astNode = astNode.getFirstChild();
          }
          AbstractExpressionHandler theParent = parent;
          if (isHandledType(astNode.getType())) {
              theParent = getHandler(indentCheck, astNode, theParent);
              createdHandlers.put(astNode, theParent);
          }
          return new MethodCallHandler(indentCheck, ast, theParent);
      }
  
      /** Clears cache of created handlers. */
      public void clearCreatedHandlers() {
          createdHandlers.clear();
      }
  
  }
  