Java Netty Client Channel Closing

Java Netty Client Channel Closing

I'm building a server and client to support multiple connections from
different people. I have done the decoders and encoders. I use ByteBuffer
and convert that into ChannelBuffer to send data. During a session, if
correct session credentials are met, then client opens up the Login
JFrame. After the JFrame is opened, the channel connected to server is
closed automatically. I'm assuming it was because the client isnt
receiving or sending any data or has nothing to do. So how can I make the
client keep checking for incoming data while during the JFrame stage?