C# 溫故而知新：Stream篇（六）

  public abstract class GirlWrapper : Girl
    {
        protected Girl girl;

        public GirlWrapper(Girl thisGril)
        {
            this.girl = thisGril;
        }
        public override void Decrorator()
        {
            girl.Decrorator();
        }
        public override string ToString()
        {
            return string.Format("{0}:{1}", this.girl.GirlName, this.girl.Nation);
        }
    }

    public class SingingGirlWrapper : GirlWrapper
    {
        public SingingGirlWrapper(Girl thisGril)
            : base(thisGril)
        {

        }
        public void Decorator() 
        {
            Console.WriteLine("SingingGirlWrapper decorateor:The girl named {0} who from {1} is {2} can singing nao", 
                this.GirlName, this.Nation, this.girl.GetType().Name);
            base.Decrorator();
        }

        public override string ToString()
        {
            return base.ToString();
        }
    }

static void Main(string[] args)
        {
            Queen queen = new Queen("Mary","Unite States");
            SingingGirlWrapper sgw = new SingingGirlWrapper(queen);
            sgw.Decorator();
            Console.ReadLine();
        }

    class Program
    {
        static void Main(string[] args)
        {
            Server server = new Server("http://www.163.com/");
            server.FetchWebPageData();
        }
    }

    public class Server
    {
        //端口
        const int webPort = 80;
        //默認接收緩存大小
        byte[] receiveBufferBytes = new byte[4096];
        //需要獲取網頁的url
        private  string webPageURL;
        public Server(string webPageUrl)
        {
            webPageURL = webPageUrl;
        }

       /// <summary>
        ///  從該網頁上獲取數據
       /// </summary>
        public void FetchWebPageData() 
        {
            if (!string.IsNullOrEmpty(webPageURL))
            FetchWebPageData(webPageURL);
            Console.ReadLine();
        }

        /// <summary>
        /// 從該網頁上獲取數據
        /// </summary>
        /// <param name="webPageURL">網頁url</param>
        private void FetchWebPageData(string webPageURL) 
        {
            //通過url獲取主機信息
            IPHostEntry iphe = Dns.GetHostEntry(GetHostNameBystrUrl(webPageURL));
            Console.WriteLine("遠程服務器名： {0}", iphe.HostName);
            //通過主機信息獲取其IP
            IPAddress[] address = iphe.AddressList;
            IPEndPoint ipep = new IPEndPoint(address[0], 80);
            //實例化一個socket用于接收網頁數據
            Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            //連接
            socket.Connect(ipep);
            if (socket.Connected)
            {
                //發送頭文件，這樣才能下載網頁數據
                socket.Send( Encoding.ASCII.GetBytes( this.GetHeader(webPageURL)));
            }
            else { return; }
            //接收頭一批數據
            var count = socket.Receive(receiveBufferBytes);
            //轉化成string 
            var getString = Encoding.Default.GetString(receiveBufferBytes);
           //創建文件流
            FileStream fs = new FileStream(@"d:\\Test.html", FileMode.OpenOrCreate);
            //創建緩存流
            BufferedStream bs = new BufferedStream(fs);
            using (fs)
            {
                using (bs)
                {
                    byte[] finalContent = Encoding.Default.GetBytes(getString.ToCharArray());
                    //將頭一批數據寫入本地硬盤
                    bs.Write(finalContent, 0, finalContent.Length);
                    //循環通過socket接收數據
                    while (count > 0)
                    {
                        count = socket.Receive(receiveBufferBytes, receiveBufferBytes.Length, SocketFlags.None);
                        //直接將獲取到的byte數據寫入本地硬盤
                        bs.Write(receiveBufferBytes, 0, receiveBufferBytes.Length);
                        Console.WriteLine(Encoding.Default.GetString(receiveBufferBytes));
                    }
                    bs.Flush();
                    fs.Flush();
                    bs.Close();
                    fs.Close();
                }
            }
        }
        /// <summary>
        /// 得到header
        /// </summary>
        /// <param name="url">網頁url</param>
        /// <returns>header字符串</returns>
        private string GetHeader(string webPageurl) 
        {
            return "GET " + GetRelativeUrlBystrUrl(webPageurl) + " HTTP/1.1\r\nHost: "
                + GetHostNameBystrUrl(webPageurl) + "\r\nConnection: Close\r\n\r\n";
        }

        /// <summary>
        /// 得到相對路徑
        /// </summary>
        /// <param name="strUrl">網頁url</param>
        /// <returns></returns>
        private string GetRelativeUrlBystrUrl(string strUrl)
        {
            int iIndex = strUrl.IndexOf(@"//");
            if (iIndex <= 0)
                return "/";
            string strTemp = strUrl.Substring(iIndex + 2);
            iIndex = strTemp.IndexOf(@"/");
            if (iIndex > 0)
                return strTemp.Substring(iIndex);
            else
                return "/";
        }
        /// <summary>
        /// 根據Url得到host
        /// </summary>
        /// <param name="strUrl">網頁url</param>
        /// <returns></returns>
        private string GetHostNameBystrUrl(string strUrl)
        {
            int iIndex = strUrl.IndexOf(@"//");
            if (iIndex <= 0)
                return "";
            string strTemp = strUrl.Substring(iIndex + 2);
            iIndex = strTemp.IndexOf(@"/");
            if (iIndex > 0)
                return strTemp.Substring(0, iIndex);
            else
                return strTemp;
        }

    }