Utility function for getting types of Java methods from Clojure (for debugging)

gistfile1.clj

(defn method-spy
  "Print out reflection info about a method."
  [classname methodname]
  (let [c (Class/forName classname)
        all-methods (.getDeclaredMethods c)
        matching-methods (filter #(= methodname (.getName %)) all-methods)
        pr-col (fn [name info] (println (format "%24s: %s" name info)))]
    (doseq [m matching-methods]
      (println (.toGenericString m))
      (pr-col "ReturnType" (.getReturnType m))
      (pr-col "GenericReturnType" (.getGenericReturnType m))
      (let [p-types (.getParameterTypes m)
            gp-types (.getGenericParameterTypes m)
            types (map vector p-types gp-types)
            x-types (.getExceptionTypes m)
            gx-types (.getGenericExceptionTypes m)
            exceptions (map vector x-types gx-types)]
        (doseq [type types]
          (pr-col "ParamterType" (first type))
          (pr-col "GenericParamterType" (second type)))
        (doseq [exception exceptions]
          (pr-col "ExceptionType" (first exception))
          (pr-col "GenericExceptionType" (second exception)))))))

Example usage:

=> (method-spy "redis.clients.jedis.Jedis" "rpush")

public java.lang.Long redis.clients.jedis.Jedis.rpush(java.lang.String,java.lang.String)
              ReturnType: class java.lang.Long
       GenericReturnType: class java.lang.Long
            ParamterType: class java.lang.String
     GenericParamterType: class java.lang.String
            ParamterType: class java.lang.String
     GenericParamterType: class java.lang.String

Adapted from some Oracle doc