horsin.clj

(ns udp-ping.core
  (:import (java.net DatagramPacket InetAddress MulticastSocket)))

(def port 10001)
(def group (InetAddress/getByName "224.1.0.0"))
(def buffer-size 1000)

(defn broadcast [msg]
  (let [s (MulticastSocket. port)]
    (.joinGroup s group)
    (.send s (DatagramPacket. (.getBytes msg) (.length msg) group port))))

(defn read []
  (let [s (MulticastSocket. port)
        recv (DatagramPacket. (byte-array buffer-size) buffer-size)]
    (.joinGroup s group)
    (.receive s recv)
    (println (String. (.getData recv)))))