Miscellany

import java.io.IOException;
import java.net.Socket;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.SocketChannel;
import java.nio.charset.Charset;
import java.nio.charset.CharsetDecoder;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.Set;
import java.util.Vector;

public class ReaderThread extends Thread
{
	private static final int BUFFER_SIZE = 16;
	
	private Selector readSelector = null;
	
	private ByteBuffer readBuffer;
	
	private Charset ascii = Charset.forName("US-ASCII");
	
	private CharsetDecoder asciiDecoder = ascii.newDecoder();
	
	private LinkedList<SocketChannel> connections = null;

	public ReaderThread(LinkedList<SocketChannel> connections) throws IOException
	{
		super();
		this.connections = connections;
		this.readSelector = Selector.open();
		this.readBuffer = ByteBuffer.allocateDirect(BUFFER_SIZE);
	}

	@Override
	public void run()
	{
		while (true)
		{
			try
			{
				SocketChannel channel;
				while ( (connections.size() > 0) && (null != (channel = connections.removeFirst())) )
				{
					channel.configureBlocking(false);
					channel.register(readSelector, SelectionKey.OP_READ, new StringBuffer());
				}
				
				int keysReady = readSelector.select(); // blocking

				if (keysReady > 0)
				{
					Set<SelectionKey> readyKeys = readSelector.selectedKeys();

					for (SelectionKey key : readyKeys )
					{
						readyKeys.remove(key);
						readRequest(key);
					}
				}
			} catch (Exception e)
			{
				e.printStackTrace();
			}
		}

	}

	protected void readRequest(SelectionKey key) throws Exception
	{
		SocketChannel incomingChannel = (SocketChannel) key.channel();

		try
		{

			incomingChannel.read(readBuffer);
			readBuffer.flip();
			String result = asciiDecoder.decode(readBuffer).toString();
			readBuffer.clear();

			
			System.out.print(result);
			CharBuffer chars = CharBuffer.allocate(1);
			chars.put("#");
			chars.flip();
			ByteBuffer writeBuffer = ascii.newEncoder().encode(chars);
			incomingChannel.write(writeBuffer);
			
		} catch (IOException e)
		{
			e.printStackTrace();
		}
	}
	
	public Selector getReadSelector()
	{
		return readSelector;
	}

}