java - 在套接字中发送停止消息

Question

我想要一种有效且快速的方法在套接字中发送停止消息。

我有一种将文件从一台电脑发送到另一台电脑的方法。来自发送者的所有文件都会出现在接收者的 PC 上。然而，所有数据都被写入第一个文件(仅)。其他文件存在，但为空。发生这种情况是因为接收器方法不知道何时开始写入下一个文件。

发件人

public static void sendFile (final Socket sock, File source)
{
    FileInputStream fileIn = null;

    try
{
        //Read bytes from the source file
        fileIn = new FileInputStream(source);

        //Write bytes to the receive
        //No need to use a buffered class, we make our own buffer.
        OutputStream netOut = sock.getOutputStream();

        byte[] buffer = new byte[BUFFER_SIZE];
        int read;

        while ((read = fileIn.read(buffer)) != -1)
        {
            netOut.write(buffer, 0, read);
            netOut.flush ();
        }
        //Send some stop message here
}
    catch (Exception e)
{
        e.printStackTrace ();
}
    finally
    {
        if (fileIn != null)
        {
            try
            {
                fileIn.close ();
            }
            catch (IOException e)
            {
                e.printStackTrace ();
            }
        }
    }
}

//Send files via socket
public static void sendFile (final Socket sock, File[] source)
{
    for (int i = 0; i < source.length; i++)
        sendFile (sock, source[i]);
}

接收者:

public static void receiveFile (final Socket sock, File destination)
{
    BufferedOutputStream out = null;

    try
    {
        //Receive data from socket
        InputStream clientInputStream = sock.getInputStream();

        //Write bytes to a file
        out = new BufferedOutputStream (new FileOutputStream (destination));

        byte[] buffer = new byte[BUFFER_SIZE];
        int read;
        while (true)
        {
            read = clientInputStream.read(buffer);


            out.write(buffer, 0, read);
            out.flush ();
        }
    }
    catch (IOException e)
    {
        e.printStackTrace ();
    }
    finally
    {
        if (out != null)
        {
            try
            {
                out.close ();
            }
            catch (IOException e)
            {
                e.printStackTrace();
            }
        }
    }
}

//Receive files via socket
public static void receiveFile (final Socket sock, File[] destination)
{
    for (int i = 0; i < destination.length; i++)
        receiveFile (sock, destination[i]);
}

Answer 1

在发送文件之前，您需要修改发送/接收协议(protocol)以至少包含最小 header 。您的 header 应至少包含要遵循的数据的大小以及您可能需要的任何其他内容(例如文件名)。