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Dahua ICC Open API SDK for Java

There is a newer version: 1.0.13.7

package com.dahuatech.hutool.cache.impl;

import java.io.Serializable;
import java.util.Iterator;
import java.util.NoSuchElementException;

/**
 * {@link com.dahuatech.hutool.cache.impl.AbstractCache} 的CacheObj迭代器.
 *
 * @author looly
 * @param  键类型
 * @param  值类型
 * @since 4.0.10
 */
public class CacheObjIterator implements Iterator>, Serializable {
  private static final long serialVersionUID = 1L;

  private final Iterator> iterator;
  private CacheObj nextValue;

  /**
   * 构造
   *
   * @param iterator 原{@link Iterator}
   * @param readLock 读锁
   */
  CacheObjIterator(Iterator> iterator) {
    this.iterator = iterator;
    nextValue();
  }

  /** @return 是否有下一个值 */
  @Override
  public boolean hasNext() {
    return nextValue != null;
  }

  /** @return 下一个值 */
  @Override
  public CacheObj next() {
    if (false == hasNext()) {
      throw new NoSuchElementException();
    }
    final CacheObj cachedObject = nextValue;
    nextValue();
    return cachedObject;
  }

  /** 从缓存中移除没有过期的当前值，此方法不支持 */
  @Override
  public void remove() {
    throw new UnsupportedOperationException("Cache values Iterator is not support to modify.");
  }

  /** 下一个值，当不存在则下一个值为null */
  private void nextValue() {
    while (iterator.hasNext()) {
      nextValue = iterator.next();
      if (nextValue.isExpired() == false) {
        return;
      }
    }
    nextValue = null;
  }
}