java NIO echo server

NIOEchoServer.java

import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.nio.charset.Charset;
import java.util.Iterator;

/**
 * Created by nanika on 2014/12/07.
 */
public class NIOServer {

	int port = 9999;

	private Selector selector;
	public void start() throws IOException {

		System.out.println("NIOServer start");
		selector = Selector.open();
		ServerSocketChannel serverChannel = ServerSocketChannel.open();
		serverChannel.configureBlocking(false);
		serverChannel.socket().bind(new InetSocketAddress(port));
		serverChannel.register(selector, SelectionKey.OP_ACCEPT);
		while (selector.select() > 0) {
			for (Iterator it = selector.selectedKeys().iterator(); it.hasNext();) {
				SelectionKey key = (SelectionKey) it.next();
				it.remove();
				if (key.isAcceptable()) {
					doAccept((ServerSocketChannel) key.channel());
				} else if (key.isReadable()) {
					doRead((SocketChannel) key.channel());
				}

			}
		}
		serverChannel.close();

	}

	private void doAccept(ServerSocketChannel serverChannel) throws IOException {
		System.out.println("doAccept");
		SocketChannel channel = serverChannel.accept();
		channel.configureBlocking(false);
		channel.register(selector, SelectionKey.OP_READ);
	}

	private void doRead(SocketChannel socketChannel) throws IOException {
		System.out.println("doRead");
		ByteBuffer buf = ByteBuffer.allocate(32);
		Charset cset = Charset.forName("UTF-8");
		if (socketChannel.read(buf) < 0) {
			return;
		}
		buf.flip();
		cset.decode(buf);
		buf.flip();
		socketChannel.write(buf);
	}


}