Java Tcp Server and .Net Tcp Client Problems with sending and receiving

i plan to write a Java TCP Server and a Client in C# .NET. I take Java for the Server because i have the ability to run the Server on Linux. My Problem is that the .NET Client can Connect to the Server but if i send something to the Server, the Server doesn´t receive anything.

Here is my Client:

    static void Main(string[] args)
    {
        try
        {
            System.Net.Sockets.TcpClient tcpclnt = new System.Net.Sockets.TcpClient();
            Console.WriteLine("Connecting.....");

            tcpclnt.Connect("192.168.178.26", 1337);

            Console.WriteLine("Connected");
            Console.Write("Enter the string to be transmitted : ");

            String str = Console.ReadLine();
            Stream stm = tcpclnt.GetStream();

            ASCIIEncoding asen = new ASCIIEncoding();
            byte[] ba = asen.GetBytes(str);
            Console.WriteLine("Transmitting.....");

            stm.Write(ba, 0, ba.Length);
            stm.Flush();

            byte[] bb = new byte[100];
            int k = stm.Read(bb, 0, 100);

            for (int i = 0; i < k; i++)
                Console.Write(Convert.ToChar(bb[i]));

            tcpclnt.Close();
        }

        catch (Exception e)
        {
            Console.WriteLine("Error..... " + e.StackTrace);
        }
    }

And here is my Server:

public static void main(String argv[]) throws Exception
{
    String clientSentence;
    String capitalizedSentence;

    ServerSocket socket = new ServerSocket(1337);

    while(true)
    {
        System.out.println("... Server gestartet");
        Socket connectionSocket = socket.accept();
        BufferedReader inputFromClient = new BufferedReader(new InputStreamReader(connectionSocket.getInputStream()));
        System.out.println(connectionSocket.getRemoteSocketAddress());
        DataOutputStream outputStream = new DataOutputStream(connectionSocket.getOutputStream());
        clientSentence = inputFromClient.readLine();
        System.out.println("Received: " + clientSentence);
        capitalizedSentence = clientSentence.toUpperCase() + "\n";
        outputStream.writeBytes(capitalizedSentence);
    }
}

The code i tested is only a Prototyp for Testing the connection to the Java Server. I also plan to communicate with the Java Tcp Server with iOS and maybe Windows Phone. So i hope anyone of you have an answer for me.