content: /*
   * Copyright 1999-2025 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.core.cluster.lookup;
  
  import com.alibaba.nacos.api.exception.NacosException;
  import com.alibaba.nacos.core.cluster.Member;
  import com.alibaba.nacos.core.cluster.MemberLookup;
  import com.alibaba.nacos.core.cluster.NacosMemberManager;
  
  import java.util.Collection;
  import java.util.concurrent.atomic.AtomicBoolean;
  
  /**
   * Addressable pattern base class.
   *
   * @author <a href="mailto:liaochuntao@live.com">liaochuntao</a>
   */
  public abstract class AbstractMemberLookup implements MemberLookup {
      
      protected NacosMemberManager memberManager;
      
      protected AtomicBoolean start = new AtomicBoolean(false);
      
      @Override
      public void injectMemberManager(NacosMemberManager memberManager) {
          this.memberManager = memberManager;
      }
      
      @Override
      public void afterLookup(Collection<Member> members) {
          this.memberManager.memberChange(members);
      }
      
      @Override
      public void destroy() throws NacosException {
          if (start.compareAndSet(true, false)) {
              doDestroy();
          }
      }
      
      @Override
      public void start() throws NacosException {
          if (start.compareAndSet(false, true)) {
              doStart();
          }
      }
      
      /**
       * subclass can override this method if need.
       * @throws NacosException NacosException
       */
      protected abstract void doStart() throws NacosException;
      
      /**
       * subclass can override this method if need.
       * @throws NacosException nacosException
       */
      protected abstract void doDestroy() throws NacosException;
  }
  