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.client.naming.utils;
  
  import java.util.ArrayList;
  import java.util.List;
  import java.util.concurrent.atomic.AtomicInteger;
  
  /**
   * @author nkorange
   */
  public class GenericPoller<T> implements Poller<T> {
  
      private AtomicInteger index = new AtomicInteger(0);
      private List<T> items = new ArrayList<T>();
  
      public GenericPoller(List<T> items) {
          this.items = items;
      }
  
      @Override
      public T next() {
          return items.get(Math.abs(index.getAndIncrement() % items.size()));
      }
  
      @Override
      public Poller<T> refresh(List<T> items) {
          return new GenericPoller<T>(items);
      }
  }
  