udp_proof_of_concept.clj

(import '(java.net InetAddress
                   InetSocketAddress
                   DatagramPacket
                   DatagramSocket))

; Create a SocketAddress object that holds the IP address and UDP port the
;   socket will listen to.
(let [listener-ip "127.0.0.1"
      listener-port 29000]
  (def listener-socket-address (InetSocketAddress. (InetAddress/getByName listener-ip) listener-port)))

; Create the DatagramSocket with the above SocketAddress.
(def listener-sock (DatagramSocket. listener-socket-address))

; Create a DatagramPacket to store received data.
(let [buf-len 1500]
  (def datagram-packet (DatagramPacket. (byte-array buf-len) buf-len)))

; Wait for a packet on the socket we created above.  It will store the data it
;   receives in a DatagramPacket object.  Will block the current thread until
;   it receives a packet.
(do (.receive listener-sock datagram-packet))

; Do something with the data received.
(prn (String. (.getData datagram-packet)))

; one way to verify operation is to nmap the port:
;   nmap -sU -P0 -p 29000 127.0.0.1

A future goal is to abstract the UDP network operations out to be more functional. The above works but by clojure standards is poorly written.