content: /*
   * Copyright 1999-2023 Alibaba Group Holding Ltd.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package com.alibaba.nacos.plugin.auth.impl.persistence.handler;
  
  import com.alibaba.nacos.plugin.auth.impl.persistence.handler.support.DefaultPageHandlerAdapter;
  import com.alibaba.nacos.plugin.auth.impl.persistence.handler.support.DerbyPageHandlerAdapter;
  import com.alibaba.nacos.plugin.auth.impl.persistence.handler.support.MysqlPageHandlerAdapter;
  
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.Collections;
  import java.util.function.Consumer;
  
  /**
   * pagination factory.
   *
   * @author huangKeMing
   */
  public class PageHandlerAdapterFactory {
  
      private final List<PageHandlerAdapter> handlerAdapters;
  
      private final Map<String, PageHandlerAdapter> handlerAdapterMap;
  
      public List<PageHandlerAdapter> getHandlerAdapters() {
          return handlerAdapters;
      }
  
      public Map<String, PageHandlerAdapter> getHandlerAdapterMap() {
          return handlerAdapterMap;
      }
  
      private PageHandlerAdapterFactory() {
          List<PageHandlerAdapter> handlerAdapters = new ArrayList<>(3);
          Map<String, PageHandlerAdapter> handlerAdapterMap = new HashMap<>(3);
          Consumer<PageHandlerAdapter> addHandlerAdapter = handlerAdapter -> {
              handlerAdapters.add(handlerAdapter);
              handlerAdapterMap.put(handlerAdapter.getClass().getName(), handlerAdapter);
          };
          // MysqlPageHandlerAdapter
          addHandlerAdapter.accept(new MysqlPageHandlerAdapter());
          // DerbyPageHandlerAdapter
          addHandlerAdapter.accept(new DerbyPageHandlerAdapter());
          // DefaultPageHandlerAdapter
          addHandlerAdapter.accept(new DefaultPageHandlerAdapter());
          this.handlerAdapters = Collections.unmodifiableList(handlerAdapters);
          this.handlerAdapterMap = Collections.unmodifiableMap(handlerAdapterMap);
      }
  
      private static final class InstanceHolder {
          static final PageHandlerAdapterFactory INSTANCE = new PageHandlerAdapterFactory();
      }
  
      public static PageHandlerAdapterFactory getInstance() {
          return InstanceHolder.INSTANCE;
      }
  
  }
  
  