Write to stream doesn´t work? Strange.

It´s me again. I hope noone minds my flood of questions.

This time it´s actually (or should be) rather simple. Only it it is not.

I am still on the client-server program. Here is a part from the server side code:

Code:

---

else if( m_bVidActive ) {
              m_oOStream.writeUTF("666:msg");
              m_oOStream.writeUTF("Sending video");
              m_oOStream.writeUTF("666:vid");
              while( m_bVidActive ) {
                      while (m_oImage == null) {
                                m_oImage = m_oImgProc.getImage();
                      }

                      if( m_oImgIcon == null )
                                m_oImgIcon = new ImageIcon(m_oImage);

                      m_oOStream.writeUTF("666:1");
                      String str = m_oIStream.readUTF();
                      while( !str.equals("666:Go") )
                                str = m_oIStream.readUTF();
                      m_oObjOutStream.writeObject(m_oImgIcon);

                      m_oImgIcon = null;
                      m_oImage = null;

                        m_oObjOutStream.reset(); //this prevents memory leak
            }
            m_oOStream.writeUTF("666:0");
}

---

And this is the respective client side code:

Code:

---

else if( str.equals("666:vid")) {
                           
        m_bVidActive = true;
                           
        while( m_bVidActive ) {
                    str = m_oIStream.readUTF();
                    if( str.equals("666:1") ) {
                            m_oOStream.writeUTF("666:Go");
                            ImageIcon icon = (ImageIcon) m_oObjInStream.readObject();
                              m_oImgProc.setImage(icon);
                              m_oWorker.imageAvailable();
                      }
                      else if( str.equals("666:0") ) {
                              m_bVidActive = false;
                      }
          }
}

---

What it does is simply transmitting images from server to client.
I still have trouble with stopping the transmission, cause as soon as, for example, the server stops and sends a message that the transmission is over, the client receives a malformed input error (obviously reading the messag via ObjectInputStream instead of datainputstream).

Anyway, the point is, that I inserted a message queue that makes the server send a message (666:1) when he´s ready to send a picture. Then he waits for the answer from the client that he is ready to receive it (666:Go). I thought it should work. Maybe there´s an easier way, but I don´t know it. The problem, though, is the message from the client (666:Go). The server simply doesn´t react to it and deadlocks in the readUTF funktion.

I know there is this thing called blocking. Maybe it´s about that. But why does it not happen with the other messages?
And as long as I am at it, is there a way to ask a Stream if it has data waiting before actually using a read-method? Cause as soon as I am in it it´s too late if there never comes a message (or the wrong kind of message). I cannot get out of that funktion then anymore.

Cheers (and thanks again)

Oceansoul