C#TCP读取所有数据-服务器端问题

Question

1. 客户端向服务器发送消息1（客户端可以是.NET或java应用程序）
2. 服务器将message2作为对Message1的响应发送回客户端

我的服务器有一个问题,它无法正确读取message1,除非我使用以下不适当的解决方案之一：

1）使用缓冲区仅为1字节的MemoryStream（工作但速度慢）：

while (true)
{
    TcpClient tcpClient = tcpListener.AcceptTcpClient();
    NetworkStream networkStream = tcpClient.GetStream();
    MemoryStream memoryStream = new MemoryStream();

    int numberOfBytesRead = 0;
    byte[] buffer = new byte[1]; // works but slow in case of big messages

    do
    {
        numberOfBytesRead = networkStream.Read(buffer, 0, buffer.Length);   
        memoryStream.Write(buffer, 0, numberOfBytesRead);
    } while (networkStream.DataAvailable);

    if (memoryStream.Length > 0)
    {
        string message1 = new StreamReader(memoryStream).ReadToEnd();
        if (message1 == "message1")
        {
            using (StreamWriter streamWriter = new StreamWriter(networkStream))
            {
                string message2 = "message2";
                streamWriter.Write(message2);
                streamWriter.Flush();
            }
        }
    }
}

while (true)
{
    TcpClient tcpClient = tcpListener.AcceptTcpClient();
    NetworkStream networkStream = tcpClient.GetStream();
    MemoryStream memoryStream = new MemoryStream();

    int numberOfBytesRead = 0;
    byte[] buffer = new byte[8192]; 

    do
    {
        numberOfBytesRead = networkStream.Read(buffer, 0, buffer.Length);   
        memoryStream.Write(buffer, 0, numberOfBytesRead);
        Thread.Sleep(1000); // works but receiving gets slow
    } while (networkStream.DataAvailable);

    if (memoryStream.Length > 0)
    {
        string message1 = new StreamReader(memoryStream).ReadToEnd();
        if (message1 == "message1")
        {
            using (StreamWriter streamWriter = new StreamWriter(networkStream))
            {
                string message2 = "message2";
                streamWriter.Write(message2);
                streamWriter.Flush();
            }
        }
    }
}

while (true)
{
    TcpClient tcpClient = tcpListener.AcceptTcpClient();
    NetworkStream networkStream = tcpClient.GetStream();
    StreamReader streamReader = new StreamReader(networkStream, true);

    string message1 = streamReader.ReadToEnd(); // blocks until client close its socket

    if (message1 == "message1")
    {
        using (StreamWriter streamWriter = new StreamWriter(networkStream))
        {
            string message2 = "message2";
            streamWriter.Write(message2); // if client close its sockets, the server cannot send this message
            streamWriter.Flush();
        }
    }
}

while (true)
{
    TcpClient tcpClient = tcpListener.AcceptTcpClient();
    NetworkStream networkStream = tcpClient.GetStream();
    StreamReader streamReader = new StreamReader(networkStream);

    StringBuilder stringBuilder = new StringBuilder();

    while (!streamReader.EndOfStream)
    {
        stringBuilder.AppendLine(streamReader.ReadLine()); // blocks until client close its socket
    }

    string message1 = stringBuilder.ToString();

    if (message1 == "message1")
    {
        using (StreamWriter streamWriter = new StreamWriter(networkStream))
        {
            string message2 = "message2";
            streamWriter.Write(message2); // if client close its sockets, the server cannot send this message
            streamWriter.Flush();
        }
    }
}

5）用其长度为message1添加前缀（可以工作，但需要客户机向消息添加额外的字节，这将不适用于现有的java客户机）

while (true)
{
    TcpClient tcpClient = tcpListener.AcceptTcpClient();
    NetworkStream networkStream = tcpClient.GetStream();
    MemoryStream memoryStream = new MemoryStream();

    byte[] bufferMessageLength = new byte[4];   // sizeof(int)
    networkStream.Read(bufferMessageLength, 0, bufferMessageLength.Length);  

    int messageLength = BitConverter.ToInt32(bufferMessageLength, 4);

    byte[] bufferMessage = new byte[messageLength]; 
    networkStream.Read(bufferMessage, 0, bufferMessage.Length); 
    memoryStream.Write(buffer, 0, bufferMessage.Length);

    if (memoryStream.Length > 0)
    {
        string message1 = new StreamReader(memoryStream).ReadToEnd();
        if (message1 == "message1")
        {
            using (StreamWriter streamWriter = new StreamWriter(networkStream))
            {
                string message2 = "message2";
                streamWriter.Write(message2);
                streamWriter.Flush();
            }
        }
    }
}

对于这些问题，在不使用上述解决方案的情况下，从客户端读取所有数据的最佳方法是什么？

Answer 1

不要使用NetworkStream.DataAvailable在消息的开头追加数据的大小。例如，邮件的长度为12501使用前4个字节作为邮件长度。

首先定义一个从缓冲区读取数据的方法

public static void ReadStream(NetworkStream reader, byte[] data)
{
    var offset = 0;
    var remaining = data.Length;
    while (remaining > 0)
    {
        var read = reader.Read(data, offset, remaining);
        if (read <= 0)
            throw new EndOfStreamException
                (String.Format("End of stream reached with {0} bytes left to read", remaining));
        remaining -= read;
        offset += read;
    }
}

然后从流中读取数据。

var bytesRead = 0;
var offset = 0;
TcpClient tcpClient = tcpListener.AcceptTcpClient();
NetworkStream networkStream = tcpClient.GetStream();
var bufferMessageSize = new byte[4]; // int32

ReadStream(networkStream, bufferMessageSize);

var messageSize = BitConverter.ToInt32(bufferMessageSize, 4); // bytesToRead

var bufferMessage = new byte[messageSize];

ReadStream(networkStream, bufferMessage);


// Now Respond back Client here
// networkStream.Write();