Java/Spring App Troubleshooting on Steroids with Clojure REPL

@Component
class ClojureReplServer {

    // public so that we can access it from Clojure
    public final static int port = 55555

    @Autowired
    private ApplicationContext ctx

    private IFn symbol = Clojure.var("clojure.core", "symbol")
    private IFn intern = Clojure.var("clojure.core", "intern")
    private IFn stopReplServer = Clojure.var("user", "stop-repl-server")
    private Object symUser = symbol.invoke("user")

    @PostConstruct
    start() {
        String res = ""
        res += intern.invoke(symUser, symbol.invoke("_injected-spring-ctx"), ctx)
        res += intern.invoke(symUser, symbol.invoke("_injected-port"), port)
        res += intern.invoke(symUser, symbol.invoke("_injected-ClojureReplServer"), this)

        // Run the init code and start the server
        IFn loadString = Clojure.var("clojure.core", "load-reader")
        def reader = new InputStreamReader(getClass().getClassLoader().getResourceAsStream("clojure-repl-init.clj"))
        res += "|" + loadString.invoke(reader)
        println("ClojureReplServer started at port ${port}, res=" + res)
    }

    @PreDestroy
    stop() {
        // Here we use `stop-repl-server` defined in clojure-repl-init.clj:
        stopReplServer.invoke()
        Agent.soloExecutor.shutdown()
    }

    /** Called from Clojure when we screw up and need to reset vars etc */
    void reset() {
        // Calling start is enough; the server will not be started again thanks to `defonce`
        start()
    }
}

(in-ns 'user)
(require
    '[clojure.reflect :refer [reflect]]
    '[clojure.repl :refer [doc]]
    '[clojure.string :as s]
    '[nrepl.server :as n]))

;; Provide an alias since we are going to use `bean` for Spring:
;; (we need the value to be fn? and to have the bean's docstring; I don't know of a better way:)
(intern 'user (with-meta 'jb    (meta #'clojure.core/bean)) clojure.core/bean)
(intern 'user (with-meta 'jbean (meta #'clojure.core/bean)) clojure.core/bean)

;; Helper functions
(defn help
    "List our helper functions (and vars)"
    []
    (println "Helper functions available in the user namespace:")
    (->> (vals (ns-publics 'user))
        (filter #(fn? (deref %)))
        (map #(let [{:keys [name doc]} (meta %)]
                (str "* " name (if doc (str " :- " doc) ""))))
        (sort)
        (s/join "\n")
        (println))
    (println "\nYou can also use `(doc a-fn)` and `(reflect an-object)`.")
    (println "Remember that *1 holds the result of the last call and *e the last error."))

(defn list-beans
    "List all Spring Beans; ex: `(list-beans)`"
    []
    (seq (.getBeanDefinitionNames user/_injected-spring-ctx)))

(defn find-bean
    "List all Spring bean names containing the given substring (case-insensitive)"
    [substring]
    (filter
        #(re-matches
            (re-pattern
                (str "(?i).*" substring ".*")) %)
        (list-beans)))

(defn bean
    "Get Spring Bean by a name (from (list-beans)); ex: `(bean \"configService\")`"
    [name]
    (.getBean user/_injected-spring-ctx name))

(defn members
    "Show public methods, fields of a bean; ex: `(members aBean)`"
    [bean]
    (->> bean clojure.reflect/reflect :members (filter (comp :public :flags)) (map :name)))

(defonce server (n/start-server :port user/_injected-port))

(defn stop-repl-server
    "Called from ClojureReplServer upon exit; don't use directly"
    []
    (n/stop-server server))

(defn reset
    "Reset the pre-defined functions and vars in the case that you messed up with them. Does not remove vars you made (we'd need clojure.tools/refresh for that)."
    []
    (.reset user/_injected-ClojureReplServer))

// build.gradle:
compile "org.clojure:clojure:1.10.0"
compile "nrepl:nrepl:0.5.0"