content: /*
   * Copyright 1999-2018 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;
  
  import com.alibaba.nacos.common.notify.Event;
  import com.alibaba.nacos.common.notify.listener.Subscriber;
  
  /**
   * Node change listeners.
   *
   * @author <a href="mailto:liaochuntao@live.com">liaochuntao</a>
   */
  @SuppressWarnings("PMD.AbstractClassShouldStartWithAbstractNamingRule")
  public abstract class MemberChangeListener extends Subscriber<MembersChangeEvent> {
      
      /**
       * return NodeChangeEvent.class info.
       *
       * @return {@link MembersChangeEvent#getClass()}
       */
      @Override
      public Class<? extends Event> subscribeType() {
          return MembersChangeEvent.class;
      }
      
      /**
       * Whether to ignore expired events.
       *
       * @return default value is {@link Boolean#TRUE}
       */
      @Override
      public boolean ignoreExpireEvent() {
          return true;
      }
  }
  