Trouble with Netty IdleStateHandler - am I testing it the wrong way?

Question

I have a toy Netty server and am trying to send heartbeat messages to clients when nothing has happened on their channels. I am testing this by telnetting to the server, writing

Answer 1

You missed to add the HeartbeatHandler in the ChannelPipeline. You need to add IdleStateHandler AND HeartbeatHandler to the ChannelPipeline to have it work.

Answer 2

Norman’s answer is a really helpful,but what I'd like to point out another thing: the idleStateHandler and the heartbeatHandler should be channel specific, so in the PipeLineFactory , you shouldn't construct these two handlers as private members, but need to create new ones in the getPipeline() method. You's also have a channel map to save the constructed channels, if you need to release them, you'd better also stop the timer to release the resources.