package com.manning.nettyinaction.chapter8;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.Channel;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.handler.timeout.IdleStateEvent;
import io.netty.handler.timeout.IdleStateHandler;
import io.netty.util.CharsetUtil;
import java.util.concurrent.TimeUnit;
/**
* Listing 8.7 of <i>Netty in Action</i>
*
* @author <a href="mailto:nmaurer@redhat.com">Norman Maurer</a>
*/
public class IdleStateHandlerInitializer extends ChannelInitializer<Channel> {
@Override
protected void initChannel(Channel ch) throws Exception {
ChannelPipeline pipeline = ch.pipeline();
pipeline.addLast(new IdleStateHandler(0, 0, 60, TimeUnit.SECONDS));
pipeline.addLast(new HeartbeatHandler());
}
public static final class HeartbeatHandler extends ChannelInboundHandlerAdapter {
private static final ByteBuf HEARTBEAT_SEQUENCE = Unpooled.unreleasableBuffer(
Unpooled.copiedBuffer("HEARTBEAT", CharsetUtil.ISO_8859_1));
@Override
public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
if (evt instanceof IdleStateEvent) {
ctx.writeAndFlush(HEARTBEAT_SEQUENCE.duplicate())
.addListener(ChannelFutureListener.CLOSE_ON_FAILURE);
} else {
super.userEventTriggered(ctx, evt);
}
}
}
}