Question

I’m attempting to perform a synchronous write/read in a demux-based client application with MINA 2.0 RC1, but it seems to get stuck. Here is my code:

public boolean login(final String username, final String password) {
    // block inbound messages
    session.getConfig().setUseReadOperation(true);

    // send the login request
    final LoginRequest loginRequest = new LoginRequest(username, password);
    final WriteFuture writeFuture = session.write(loginRequest);
    writeFuture.awaitUninterruptibly();

    if (writeFuture.getException() != null) {
        session.getConfig().setUseReadOperation(false);
        return false;
    }

    // retrieve the login response
    final ReadFuture readFuture = session.read();
    readFuture.awaitUninterruptibly();

    if (readFuture.getException() != null) {
        session.getConfig().setUseReadOperation(false);
        return false;
    }

    // stop blocking inbound messages
    session.getConfig().setUseReadOperation(false);

    // determine if the login info provided was valid
    final LoginResponse loginResponse = (LoginResponse)readFuture.getMessage();
    return loginResponse.getSuccess();
}

I can see on the server side that the LoginRequest object is retrieved, and a LoginResponse message is sent. On the client side, the DemuxingProtocolCodecFactory receives the response, but after throwing in some logging, I can see that the client gets stuck on the call to readFuture.awaitUninterruptibly().

I can’t for the life of me figure out why it is stuck here based upon my own code. I properly set the read operation to true on the session config, meaning that messages should be blocked. However, it seems as if the message no longer exists by time I try to read response messages synchronously.

Any clues as to why this won’t work for me?

Answer 1

The reason this wasn’t working for me was because of an issue elsewhere in my code where I stupidly neglected to implement the message response encoder/decoder. Ugh. Anyway, the code in my question worked as soon as I fixed that.