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创建了一个异步 tcp 客户端和服务器,程序在传输文本文件而不是二进制文件时工作正常。发送和接收的字节数匹配,但二进制文件无法运行。pdf内容为空,zip无法提取等。任何提示,谢谢。

客户

using System;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using System.Text;
using System.IO;

// State object for receiving data from remote device.
public class StateObject
{
    // Client socket.
    public Socket workSocket = null;
    // Size of receive buffer.
    public const int BufferSize = 256;
    // Receive buffer.
    public byte[] buffer = new byte[BufferSize];
    // Received data string.
    public StringBuilder sb = new StringBuilder();
}

public class AsynClient
{
    // The port number for the remote device.
    private const int port = 11000;

    // ManualResetEvent instances signal completion.
    private static ManualResetEvent connectDone = new ManualResetEvent(false);
    private static ManualResetEvent sendDone = new ManualResetEvent(false);
    private static ManualResetEvent receiveDone = new ManualResetEvent(false);

    // The response from the remote device.
    private static String response = String.Empty;
    private static String endofFile = "<EOF>";

    private static void StartClient()
    {
        // Connect to a remote device.
        try
        {
            // Establish the remote endpoint for the socket.
            // The name of the 
            // remote device is "host.contoso.com".
            IPHostEntry ipHostInfo = Dns.Resolve("128.127.12.41");
            IPAddress ipAddress = ipHostInfo.AddressList[0];            
            IPEndPoint remoteEP = new IPEndPoint(ipAddress, port);

            // Create a TCP/IP socket.
            Socket client = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

            // Connect to the remote endpoint.
            client.BeginConnect(remoteEP, new AsyncCallback(ConnectCallback), client);
            connectDone.WaitOne();

            // Send test data to the remote device.
            //Send(client, "This is a test<EOF>");
            Send(client, readFile());
            sendDone.WaitOne();

            // Receive the response from the remote device.
            Receive(client);
            receiveDone.WaitOne();

            // Write the response to the console.
            Console.WriteLine("Response received : {0}", response);

            // Release the socket.
            client.Shutdown(SocketShutdown.Both);
            client.Close();

        }
        catch (Exception e)
        {
            Console.WriteLine(e.ToString());
        }
    }

    //private static String readFile()
    private static byte[] readFile()
    {
        String filePath = "C:\\way\\interface\\";
        //String fileName = "DC5_2013-04-08_20130828111230.zip";
        String fileName = "DC5_2013-06-01_20130828183818.zip";

        fileName = fileName.Replace("\\", "/");
        while (fileName.IndexOf("/") > -1)
        {
            filePath += fileName.Substring(0, fileName.IndexOf("/") + 1);
            fileName = fileName.Substring(fileName.IndexOf("/") + 1);
        }

        byte[] fileNameByte = Encoding.ASCII.GetBytes(fileName);        
        if (fileNameByte.Length > 850 * 1024)
        {            
            Console.WriteLine("File size is more than 850kb, please try with small file.");            
        }

        byte[] fileNameLen = BitConverter.GetBytes(fileNameByte.Length);

        byte[] fileData = File.ReadAllBytes(filePath + fileName);        
        byte[] eofByte = Encoding.ASCII.GetBytes(endofFile);

        byte[] clientData = new byte[4 + fileNameByte.Length + fileData.Length + endofFile.Length];

        fileNameLen.CopyTo(clientData, 0);        
        fileNameByte.CopyTo(clientData, 4);
        fileData.CopyTo(clientData, 4 + fileNameByte.Length);
        eofByte.CopyTo(clientData, 4 + fileNameByte.Length + fileData.Length);               

        //return System.Text.Encoding.Default.GetString(clientData);
        return clientData;
    }

    private static void ConnectCallback(IAsyncResult ar)
    {
        try
        {
            // Retrieve the socket from the state object.
            Socket client = (Socket)ar.AsyncState;

            // Complete the connection.
            client.EndConnect(ar);

            Console.WriteLine("Socket connected to {0}", client.RemoteEndPoint.ToString());

            // Signal that the connection has been made.
            connectDone.Set();
        }
        catch (Exception e)
        {
            Console.WriteLine(e.ToString());
        }
    }

    private static void Receive(Socket client)
    {
        try
        {
            // Create the state object.
            StateObject state = new StateObject();
            state.workSocket = client;

            // Begin receiving the data from the remote device.
            client.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
                new AsyncCallback(ReceiveCallback), state);
        }
        catch (Exception e)
        {
            Console.WriteLine(e.ToString());
        }
    }

    private static void ReceiveCallback(IAsyncResult ar)
    {
        try
        {
            // Retrieve the state object and the client socket 
            // from the asynchronous state object.
            StateObject state = (StateObject)ar.AsyncState;
            Socket client = state.workSocket;

            // Read data from the remote device.
            int bytesRead = client.EndReceive(ar);

            if (bytesRead > 0)
            {
                // There might be more data, so store the data received so far.
                state.sb.Append(Encoding.ASCII.GetString(state.buffer, 0, bytesRead));

                // Get the rest of the data.
                client.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
                    new AsyncCallback(ReceiveCallback), state);
            }
            else
            {
                // All the data has arrived; put it in response.
                if (state.sb.Length > 1)
                {
                    response = state.sb.ToString();
                }
                // Signal that all bytes have been received.
                receiveDone.Set();
            }
        }
        catch (Exception e)
        {
            //Console.WriteLine(e.ToString());

            StateObject state = (StateObject)ar.AsyncState;
            if (state.sb.Length > 1)
            {
                response = state.sb.ToString();
            }
            // Signal that all bytes have been received.
            receiveDone.Set();             
        }
    }

    private static void Send(Socket client, byte[] byteData)
    {        
        // Begin sending the data to the remote device.
        client.BeginSend(byteData, 0, byteData.Length, 0,
            new AsyncCallback(SendCallback), client);
    }

    private static void Send(Socket client, String data)
    {
        // Convert the string data to byte data using ASCII encoding.
        byte[] byteData = Encoding.ASCII.GetBytes(data);

        // Begin sending the data to the remote device.
        client.BeginSend(byteData, 0, byteData.Length, 0,
            new AsyncCallback(SendCallback), client);
    }

    private static void SendCallback(IAsyncResult ar)
    {
        try
        {
            // Retrieve the socket from the state object.
            Socket client = (Socket)ar.AsyncState;

            // Complete sending the data to the remote device.
            int bytesSent = client.EndSend(ar);
            Console.WriteLine("Sent {0} bytes to server.", bytesSent);

            // Signal that all bytes have been sent.
            sendDone.Set();
        }
        catch (Exception e)
        {
            Console.WriteLine(e.ToString());
        }
    }

    public static int Main(String[] args)
    {
        StartClient();
        return 0;
    }
}

服务器

using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using System.IO;

// State object for reading client data asynchronously
public class StateObject
{
    // Client  socket.
    public Socket workSocket = null;
    // Size of receive buffer.
    public const int BufferSize = 860 * 1024;
    // Receive buffer.
    public byte[] buffer = new byte[BufferSize];
    // Received data string.
    public StringBuilder sb = new StringBuilder();
}

public class AsynServer
{
    // Thread signal.
    public static ManualResetEvent allDone = new ManualResetEvent(false);
    public static string receivedPath = "C:/way/dw";
    private static String endofFile = "<EOF>";

    public AsynServer()
    {
    }

    public static void StartListening()
    {
        // Data buffer for incoming data.
        byte[] bytes = new Byte[1024];

        // Establish the local endpoint for the socket.
        // The DNS name of the computer
        // running the listener is "host.contoso.com".
        IPHostEntry ipHostInfo = Dns.Resolve(Dns.GetHostName());
        IPAddress ipAddress = ipHostInfo.AddressList[0];
        IPEndPoint localEndPoint = new IPEndPoint(ipAddress, 11000);

        // Create a TCP/IP socket.
        Socket listener = new Socket(AddressFamily.InterNetwork,
            SocketType.Stream, ProtocolType.Tcp);

        // Bind the socket to the local endpoint and listen for incoming connections.
        try
        {
            listener.Bind(localEndPoint);
            listener.Listen(100);

            while (true)
            {
                // Set the event to nonsignaled state.
                allDone.Reset();

                // Start an asynchronous socket to listen for connections.
                Console.WriteLine("Waiting for a connection...");
                listener.BeginAccept(
                    new AsyncCallback(AcceptCallback),
                    listener);

                // Wait until a connection is made before continuing.
                allDone.WaitOne();
            }

        }
        catch (Exception e)
        {
            Console.WriteLine(e.ToString());
        }

        Console.WriteLine("\nPress ENTER to continue...");
        Console.Read();

    }

    public static void AcceptCallback(IAsyncResult ar)
    {
        // Signal the main thread to continue.
        allDone.Set();

        // Get the socket that handles the client request.
        Socket listener = (Socket)ar.AsyncState;
        Socket handler = listener.EndAccept(ar);

        // Create the state object.
        StateObject state = new StateObject();
        state.workSocket = handler;
        handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
            new AsyncCallback(ReadCallback), state);
    }

    public static void ReadCallback(IAsyncResult ar)
    {
        String content = String.Empty;        

        // Retrieve the state object and the handler socket
        // from the asynchronous state object.
        StateObject state = (StateObject)ar.AsyncState;
        Socket handler = state.workSocket;

        // Read data from the client socket. 
        int bytesRead = handler.EndReceive(ar);

        if (bytesRead > 0)
        {            
            // There  might be more data, so store the data received so far.
            state.sb.Append(Encoding.ASCII.GetString(
                state.buffer, 0, bytesRead));            

            // Check for end-of-file tag. If it is not there, read 
            // more data.
            content = state.sb.ToString();            
            //Console.WriteLine(content);
            if (content.IndexOf("<EOF>") > -1)
            {
                // All the data has been read from the 
                // client. Display it on the console.
                //Console.WriteLine("Read {0} bytes from socket. \n Data : {1}", content.Length, content);
                Console.WriteLine("Read {0} bytes from socket.", content.Length);

                byte[] byteStream = System.Text.Encoding.UTF8.GetBytes(state.sb.ToString());
                int fileNameLen = BitConverter.ToInt32(byteStream, 0);                
                String fileName = Encoding.ASCII.GetString(byteStream, 4, fileNameLen);                

                writeFile(fileName, fileNameLen, byteStream.Length, byteStream);                


                // Echo the data back to the client.
                //Send(handler, content);
                Send(handler, "OK");
            }
            else
            {
                // Not all data received. Get more.
                handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
                new AsyncCallback(ReadCallback), state);
            }
        }
    }

    private static void writeFile(String fileName, int fileNameLen, int receiveByte, byte[] receiveBuffer)
    {        
        BinaryWriter bWrite = new BinaryWriter(File.Open(receivedPath + "/" + fileName, FileMode.Append));                
        bWrite.Write(receiveBuffer, 4 + fileNameLen, receiveByte - 4 - fileNameLen - endofFile.Length);
        bWrite.Close();
    }

    private static void Send(Socket handler, String data)
    {
        // Convert the string data to byte data using ASCII encoding.
        byte[] byteData = Encoding.ASCII.GetBytes(data);

        // Begin sending the data to the remote device.
        handler.BeginSend(byteData, 0, byteData.Length, 0,
            new AsyncCallback(SendCallback), handler);
    }

    private static void SendCallback(IAsyncResult ar)
    {
        try
        {
            // Retrieve the socket from the state object.
            Socket handler = (Socket)ar.AsyncState;

            // Complete sending the data to the remote device.
            int bytesSent = handler.EndSend(ar);
            Console.WriteLine("Sent {0} bytes to client.", bytesSent);

            handler.Shutdown(SocketShutdown.Both);
            handler.Close();

        }
        catch (Exception e)
        {
            Console.WriteLine(e.ToString());
        }
    }


    public static int Main(String[] args)
    {
        StartListening();
        return 0;
    }
}
4

1 回答 1

2

主要问题在于您在服务器上的接收代码。您正在使用以下方法将二进制数据转换为字符串:

        // There  might be more data, so store the data received so far.
        state.sb.Append(Encoding.ASCII.GetString(
            state.buffer, 0, bytesRead));            

ASCII 是 7 位编码。任何不在 0 到 127 范围内的字符都将转换为“?”。因此,大约一半的二进制数据被转换为问号。

您在这里遇到的另一个问题是字符串是否"<EOF>"出现在文本文件(或二进制文件)中的某处。如果发生这种情况,您的接收器将在读取整个文件之前退出。

您应该更改您的协议,而不是发送一个"<EOF>"字符串,而是将您发送的内容的总长度放在您发送的数据的前 4 个字节中。您的接收代码读取前 4 个字节并知道它应该接收的总字节数。

收到时将所有内容视为二进制文件。当您提取文件名时,您只需将这些字节转换为字符串。但是所有文件数据都必须被视为二进制。只需将其直接写入输出文件即可。或者,如果需要,您可以将其缓冲在内存中。

Encoding.ASCII什至不建议使用文件名。Windows 文件名中可能包含非 ASCII 字符。我建议使用Encoding.UTF8,它将 ASCII 字符编码为单个字节,但也允许使用完整的 Unicode 字符集。

于 2013-08-29T03:17:05.437 回答