/// <summary>
 /// 反序列化
 /// </summary>
 /// <param name="info">SerializationInfo</param>
 /// <param name="context">StreamingContext</param>
 protected UrlExtractor(SerializationInfo info, StreamingContext context)
 {
     this.rulers         = info.GetValue("rulers", typeof(UrlRulerCollection)) as UrlRulerCollection;
     this.onlySameDomain = info.GetBoolean("onlySameDomain");
     this.onlySameHost   = info.GetBoolean("onlySameHost");
     this.extractFinal   = info.GetBoolean("extractFinal");
 }
        private bool extractFinal;         //指示是否在最终链接中进行URL抽取

        /// <summary>
        /// 构造函数
        /// </summary>
        protected UrlExtractor()
        {
            this.rulers         = new UrlRulerCollection();
            this.onlySameDomain = true;
            this.onlySameHost   = true;
            this.extractFinal   = false;
        }