title: How to refuse incoming connections in Netty?
body: <p>I have a Netty TCP server, and I want to reject/refuse incoming connection attempts selectively (based on their remote address). I guess I have to use <code>ServerBootstrap.setParentHandler(ChannelHandler)</code>, but what do I do in the <code>ChannelHandler</code>? What event am I handling? How do I refuse the connection?</p>