Socket編程 (異步通訊,解決Tcp粘包) - Part3

Socket編程 (異步通訊,解決Tcp粘包)

　　從上一章的通訊中，我們發現如果使用Tcp連續發送消息會出現消息一起發送過來的情況，這樣給我們編程造成一定的問題，給我們的信息解析造成一定的問題。那么這篇文章就將針對以上問題給出解決方案......

 

問題一般會出現的情況如下,假設我們連續發送兩條兩天記錄("我是liger_zql")：

模擬發送示例：

　#region 測試消息發送,並匹配協議
  TcpClient client = new TcpClient();
  client.AsynConnect();
  Console.WriteLine("下面將連續發送2條測試消息...");
  Console.ReadKey();
  MessageProtocol msgPro;
  for (int i = 0; i < 2; i++)
  {
  　　msgPro = new MessageProtocol("我是liger_zql");
  　　Console.WriteLine("第{0}條：{1}", i + 1, msgPro.MessageInfo.Content);
  　　client.AsynSend(msgPro);
  }
  #endregion

接收端接受兩條信息會出現如下三種情況：

　　1.(1)我是liger_zql(2)我是liger_zql

　　2.(1)我是liger_zql我是(2)liger_zql

　　3.(1)我是liger_zql我是liger_zql

通過以上三種情況，顯然2、3都不是我們想要的結果。那么如何處理這中情況呢？

解決方案：通過自定義協議...

我們可以以將信息以xml的格式發送出去，列入<protocol>content</protocol>通過正則匹配信息是否完整，如果不完整，我們可以先將本次接受信息緩存接受下一次信息，再次匹配得到相應的結果。

將信息對象轉換成一定格式的xml字符串：

　　 /// <summary>
    /// 文本信息
    /// </summary>
    public class MessageInfo
    {
        public string Content { get; set; }//信息內容
        public MessageInfo(string content)
        {
            this.Content = content;
        }
        public override string ToString()
        {
            return String.Format("<message Content=\"{0}\" />", this.Content);
        }
    }

    /// <summary>
    /// 文件信息
    /// </summary>
    public class RequestFile
    {
        public string Address { get; set; }//發送端Ip
        public int Port { get; set; }//端口號
        public RequestMode Mode { get; set; }//請求類
        public FileObject FileObject { get; set; }//文件詳細參數
        public RequestFile() { }
        public RequestFile(RequestMode mode, FileObject fileobject)
        {
            this.Mode = mode;
            this.FileObject = fileobject;
        }
        public RequestFile(string address, int port, RequestMode mode, FileObject fileobject)
        {
            this.Address = address;
            this.Port = port;
            this.Mode = mode;
            this.FileObject = fileobject;
        }
        public RequestFile(string address, int port, RequestMode mode, string filename, long filelength, int packetsize, long packetcount)
        {
            this.Address = address;
            this.Port = port;
            this.Mode = mode;
            this.FileObject = new FileObject(filename, filelength, packetsize, packetcount);
        }
        public override string ToString()
        {
            StringBuilder sbString = new StringBuilder();
            sbString.Append("<message ");
            sbString.Append(String.Format("Address=\"{0}\" ", Address));
            sbString.Append(String.Format("Port=\"{0}\" ", Port));
            sbString.Append(String.Format("Mode=\"{0}\" ", Mode));
            sbString.Append(String.Format("FileName=\"{0}\" ", FileObject.FileName));
            sbString.Append(String.Format("FileLength=\"{0}\" ", FileObject.FileLength));
            sbString.Append(String.Format("PacketSize=\"{0}\" ", FileObject.PacketSize));
            sbString.Append(String.Format("PacketCount=\"{0}\" ", FileObject.PacketCount));
            sbString.Append("/>");
            return sbString.ToString();
        }
    }
    /// <summary>
    /// 訂立信息協議
    /// </summary>
    public class MessageProtocol
    {
        public MessageType MessageType { get; set; }
        public MessageInfo MessageInfo { get; set; }
        public RequestFile RequestFile { get; set; }
        public MessageProtocol() { }
        public MessageProtocol(string msg)
        {
            MessageType = MessageType.text;
            MessageInfo = new MessageInfo(msg);
        }
        public MessageProtocol(RequestMode mode, FileObject fileobject)
        {
            MessageType = MessageType.file;
            RequestFile = new RequestFile(mode, fileobject);
        }
        public MessageProtocol(string address, int port, RequestMode mode, FileObject fileobject)
        {
            MessageType = MessageType.file;
            RequestFile = new RequestFile(address, port, mode, fileobject);
        }
        public override string ToString()
        {
            StringBuilder sbString = new StringBuilder();
            sbString.Append(String.Format("<protocol Type=\"{0}\">", MessageType));
            if (MessageType == MessageType.text)
            {
                sbString.Append(MessageInfo.ToString());
            }
            else
            {
                sbString.Append(RequestFile.ToString());
            }
            sbString.Append("</protocol>");
            return sbString.ToString();
        }
        public byte[] ToBytes()
        {
            return Encoding.UTF8.GetBytes(this.ToString());
        }
    }

對接收的信息通過正則進行匹配處理：

　　　　 //臨時緩存
        public string temp = string.Empty;
        //匹配協議獲取信息
        public List<MessageProtocol> HandlerString(string msg)
        {
            List<MessageProtocol> msgProList = new List<MessageProtocol>();
            if (!String.IsNullOrEmpty(temp))
            {
                msg = temp + msg;
            }
            string pattern = "(^<protocol Type=.*?>.*?</protocol>)";
            if (Regex.IsMatch(msg, pattern))
            {
                //匹配協議內容
                string match = Regex.Match(msg, pattern).Groups[0].Value;
                //將匹配的內容添加到集合
                msgProList.Add(HandlerObject(match));
                temp = string.Empty;
                //截取未匹配字符串，進行下一次匹配
                msg = msg.Substring(match.Length);
                if (!String.IsNullOrEmpty(msg))
                {
                    msgProList.AddRange(HandlerString(msg));
                }
            }
            else
            {
                temp = msg;
            }
            return msgProList;
        }

然后將該定義的協議換換成信息對象，通過對象獲取自己想要的信息。

        //將已轉成協議信息轉成對象信息
        public MessageProtocol HandlerObject(string protocol)
        {
            XmlDocument xmldoc = new XmlDocument();
            xmldoc.LoadXml(protocol);
            XmlNode root = xmldoc.DocumentElement;
            XmlNode msgnode = root.SelectSingleNode("message");
            MessageProtocol msgPro = new MessageProtocol();
            if (root.Attributes["Type"].Value == MessageType.text.ToString())
            {
                msgPro.MessageType = MessageType.text;
                msgPro.MessageInfo = new MessageInfo(msgnode.Attributes["Content"].Value);
            }
            else
            {
                msgPro.MessageType = MessageType.file;
                RequestMode mode = (RequestMode)Enum.Parse(typeof(RequestMode), msgnode.Attributes["Mode"].Value);
                FileObject fileobject = new FileObject();
                fileobject.FileName = msgnode.Attributes["FileName"].Value;
                fileobject.FileLength = Convert.ToInt64(msgnode.Attributes["FileLength"].Value);
                fileobject.PacketSize = Convert.ToInt32(msgnode.Attributes["PacketSize"].Value);
                fileobject.PacketCount = Convert.ToInt64(msgnode.Attributes["PacketCount"].Value);
                msgPro.RequestFile = new RequestFile(
                    msgnode.Attributes["Address"].Value,
                    Convert.ToInt32(msgnode.Attributes["Port"].Value),
                    mode, fileobject);
            }
            return msgPro;
        }        

最后運行結果如下：

好了Tcp粘包的問題我們解決了。下一章我們將解決Udp丟包的個人解決方案！

附上源碼：SocketProQuests.zip

作者：曾慶雷
出處：http://www.cnblogs.com/zengqinglei
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