//********* Non-blocking client ***************************************
import java.nio.ByteBuffer;
import java.nio.channels.SocketChannel;
import java.net.InetSocketAddress;

public class NBC {  // NonBlockingClient
    public static void main(String[ ] args) throws Exception {
        if (args.length < 1) {
          System.err.println("Usage: NBC <server's addr>");
          return;
        }
        // Create a ByteBuffer to receive data.
        ByteBuffer buff = ByteBuffer.allocate(buff_size);

        // Open a socket channel and configure it as blocking.
        SocketChannel sc = SocketChannel.open();
        sc.configureBlocking(false);

        // Attempt to connect: as blocking is off, the connect
        // call returns at once
        sc.connect(new InetSocketAddress(args[0], port));
        
        // Now wait until the connection is finished.
        // (There's a better way.)
        while (!sc.finishConnect())
            Thread.sleep(500);      
    
        // Read from the channel when data are available.
        // (There's a better way.)
        while (sc.read(buff) != -1) // -1 marks end of stream
            Thread.sleep(500);
        sc.close();
        System.out.println(new String(buff.array()));
    }
    private static final int port = 2233;
    private static final int buff_size = 512; // in bytes
}