Example of defining a topology in Clojure

gistfile1.clj

(use 'backtype.storm.clojure)
(use 'backtype.storm.config)
(require '[backtype.storm [thrift :as thrift]])
(import 'storm.starter.spout.RandomSentenceSpout)
(import 'backtype.storm.LocalCluster)

(defboltfull suffix-bolt ["word"]
  :params [suffix]
  :let [conf-state (atom nil)]
  :prepare ([conf context collector]
              (reset! conf-state conf))
  :execute ([tuple collector]
              (.emit collector tuple [(str (.getValue tuple 0) suffix)])
              (.ack collector tuple)
              ))

(defbolt exclamation-bolt ["word"] [tuple collector]
  (.emit collector tuple [(str (.getValue tuple 0) "!!!")])
  (.ack collector tuple))

(defn mk-topology []
  (thrift/mk-topology
   {1 (thrift/mk-spout-spec (RandomSentenceSpout.) :parallelism-hint 4)}
   {2 (thrift/mk-bolt-spec {1 :shuffle} (suffix-bolt "!!!") :parallelism-hint 3)
    3 (thrift/mk-bolt-spec {2 :shuffle} exclamation-bolt :parallelism-hint 3)}
   ))


(def cluster (LocalCluster.))
(.submitTopology cluster "test" {TOPOLOGY-DEBUG true} (mk-topology))
(Thread/sleep 10000)
(.shutdown cluster)