http-kit websocket resolve symbol - clojure

Question

Problem: I get a null pointer exception when I call the caller function in the below code if I pass it data via json from a javascript socket client. I don't get the error when I run this same code from the repl and I pass it the same data i.e.
In repl:
(def data (json/write-str {:controller "hql" :function "something"}))
(caller data)
This works fine
From javascript: this gives me s null pointer exception when calling the function caller from the handler.
<script>
var msg = {'controller': 'hql','function':'something'};
socket = new WebSocket('ws://192.168.0.7:9090');
socket.onopen = function() {
socket.send(JSON.stringify(msg));
}
socket.onmessage = function(s) {
console.log(s);
socket.close();
}
socket.onclose = function() {
console.log('Connection Closed');
}
</script>
(ns hqlserver.core
(:use [org.httpkit.dbcp :only [use-database! close-database! insert-record update-values query delete-rows]]
[org.httpkit.server])
(:require [clojure.data.json :as json]))
(defn hql [data]
(use-database! "jdbc:mysql://localhost/xxxx" "user" "xxxxx")
(let [rows (query ("select username,firstname,lastname from users order by lastname,firstname")]
(close-database!)
(json/write-str rows)))
(defn get-controller [data]
(if data
(let [data (json/read-str data :key-fn keyword)]
(data :controller))))
(defn caller [data]
((ns-resolve *ns* (symbol (get-controller data))) data))
(defn handler [request]
(with-channel request channel
(on-close channel (fn [status] (println "channel closed: " status)))
(on-receive channel (fn [data] (send! channel (caller data))))))
(defn -main [& args]
(run-server handler {:port 9090}))

Answer 1

Don't know if it's the best way but this is the solution:
Thanks to noisesmith for helping and tips....
(ns hqlserver.core
(:use [org.httpkit.dbcp :only [use-database! close-database! insert- record update-values query delete-rows]]
[org.httpkit.server]
[hqlserver.s300.login :only [login]])
(:require [clojure.data.json :as json]
[hqlserver.s300.site :refer [site-index site-update]]
[clojure.string :as str]))
(defn get-site [data]
(if data
(let [data (json/read-str data :key-fn keyword)]
(-> data :site))))
(defn get-controller [data]
(if data
(let [data (json/read-str data :key-fn keyword)]
(-> data :controller))))
(defn get-function [data]
(if data
(let [data (json/read-str data :key-fn keyword)]
(-> data :function))))
(defn caller [data]
(let [site (get-site data)]
(let [controller (get-controller data)]
(let [function (get-function data)]
(cond
(and (= site "s300")(= controller "login")(= function "login")) (login data)
(and (= site "s300")(= controller "site")(= function "site-index")) (site-index data)
(and (= site "s300")(= controller "site")(= function "site-update")) (site-update data)
:else (json/write-str {:error "No records found!"}))))))
(defn async-handler [ring-request]
(with-channel ring-request channel
(if (websocket? channel)
(on-receive channel (fn [data]
(send! channel (caller data))))
(send! channel {:status 200
:headers {"Content-Type" "text/plain"}
:body "Long polling?"}))))
(defn -main [& args]
(run-server async-handler {:port 9090}));