Handling a big amount of JMS message types

i'm new to jms, and i'm currently designing a BattleShip game. I'm using jms with activemq for the communication between them, so far i made 4 classes for jms communication which are Topic and Queue receivers and senders with simple methods of changing destination and sending.

Now i'm facing a problem when want to handle these messages, I've decided every message will be delivered via ObjectMessage and the inner object will tell the listener how to handle it.

I have 5 different categories for messages : Authentication, Data (Such as highscores, replays etc), InGameMessages (ShipRegistration, TurnUpdate and so on), ChatMessage, MatchMakingMessages (Only GameSearch and GameSearchCancel),

So i thought it will be a good idea to add a MessageType enum to each message, but eventually I ended up writing the listener with over than 20 cases at the switch statement and with a huge amount of class castings.

Now I want to write it all over again, but i'm still stuck on the message handling since I can't find a different idea, or any design pattern which can handle this issue.

Any thoughts?