import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.channels.AsynchronousServerSocketChannel;
import java.nio.channels.AsynchronousSocketChannel;
import java.nio.channels.CompletionHandler;

public class TCPServerAsync {

  private static final int BUFSIZE = 256;  // Buffer size (bytes)

  public static void main(String[] args) throws IOException, InterruptedException {

    if (args.length != 1) { // Test for correct # of args
      throw new IllegalArgumentException("Parameter(s): <Port>");
    }

    int port = Integer.parseInt(args[0]);

    final TCPProtocol protocol = new EchoAsyncProtocol(BUFSIZE);

    final AsynchronousServerSocketChannel listnChannel = AsynchronousServerSocketChannel.open();
    listnChannel.bind(new InetSocketAddress(port));

    listnChannel.accept(null, new CompletionHandler<AsynchronousSocketChannel, Void>() {
		public void cancelled(Void attachment) {
			die();
		}

		public void completed(final AsynchronousSocketChannel clntChan, Void attachment) {
			listnChannel.accept(null, this);

			try {
				protocol.handleAccept(clntChan);
			} catch (IOException e) {
			}
		}

		public void failed(Throwable exception, Void attachment) {
			die(exception);
		}
    }
    );

    Thread.sleep(500000);
  }
  
  private static void die(Throwable e) {
	  e.printStackTrace();
	  die();
  }
  
  private static void die() {
	  System.exit(1);
  }
}