ChannelHandlers
ChannelHandlers are components in Netty that intercept and process I/O events and data passing through a ChannelPipeline. They handle inbound data as it flows into the application and outbound data as it leaves, and may implement the inbound side, the outbound side, or both.
Handlers are added to a ChannelPipeline associated with a Channel. They implement the inbound interface (ChannelInboundHandler),
Lifecycle and events: Handlers receive lifecycle callbacks like handlerAdded and handlerRemoved, as well as channel lifecycle
Common patterns and considerations: ChannelHandlers are often used for decoding and encoding (protocol codecs), framing, business
Ordering and interaction: Inbound events flow from the pipeline head toward the tail, while outbound events