Java NIO connect to socket

Question

I'm trying to connect to a remote server and send a login message in my Thread:

@Override
public void run() {
    try {
        address = new InetSocketAddress(host, port);
        incomingMessageSelector = Selector.open();
        socketChannel = SocketChannel.open();           
        socketChannel.configureBlocking(false);
        socketChannel.connect(address);
        socketChannel.register(incomingMessageSelector, SelectionKey.OP_READ);
        serverManager.loginToServer();
    }
}

the loginServer() is a method which send a message to ther server but i keep getting an:

java.nio.channels.NotYetConnectedException

how can i check and wait for connection before sending this loginServer() method?

I would suggest you initially implement using blocking NIO. Its much simpler and may do what you want. Note: In NIO, the default behaviour is blocking. — Peter Lawrey, Nov 12 '12 at 16:30

user207421 · Answer 1 · 2014-08-21T06:07:31.240

If you're connecting in non-blocking mode you should:

register the channel for OP_CONNECT
when it fires call finishConnect()
if that returns true, deregister OP_CONNECT and register OP_READ or OP_WRITE depending on what you want to do next
if it returns false, do nothing, keep selecting
if either connect() or finishConnect() throws an exception, close the channel and try again or forget about it or tell the user or whatever is appropriate.

If you don't want to do anything until the channel connects, do the connect in blocking mode and go into non-blocking mode when the connect succeeds.

score -1 · Answer 2 · answered Nov 12 '12 at 16:30

-1

i've found an answer.. i should use:

    socketChannel = SocketChannel.open(address);            
    socketChannel.configureBlocking(false);

    while (!socketChannel.finishConnect());

   //my code after connection

because the NIO is in not blocking mode we have to wait until it finish its connection

answered Nov 12 '12 at 16:30

Asaf Nevo

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This is pointless. Just do the connect in blocking mode and avoid smoking the CPU. Or else register OP_CONNECT and use select() and call finishConnect() when it fires. – user207421 Nov 13 '12 at 03:22

Java NIO connect to socket

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