large_java_objects.clj

;;
;; Several methods that were helpful in development when working with large
;;   legacy java objects. I wouldn't be too surprised if somebody told me that
;;   emacs does some of this stuff already
;;


;; This function (which is arguably not really an appropriate use of multimethods)
;; is an alternative to the (bean) method, which I found returns a "map" that
;; will throw an exception if
;; you pass in a missing key (unlike a vanilla map, which just returns nil). So
;; this converts to a vanilla map
(defmulti safe-bean #(.isArray (class %)))
(defmethod safe-bean true [ob] (apply vector ob))
(defmethod safe-bean false [ob]
  (apply hash-map (reduce concat (bean ob))))

;;
;; This method is similar to bean, but works on heavily nested java objects:
;;   Pass in a nested map with a list of keys, and it will return a copy where
;;   the java object reached by the list of keys has been expanded by (safe-bean)
;;
(defn bean-expand
  "Just for dev stuff. Not a real function."
  ([ob] (safe-bean ob))
  ([ob key & keyz]
    (assoc ob key (apply bean-expand (cons (ob key) keyz)))))

;;
;; And this is an example use of the above function, where a single java object is
;; run through bean-expand some twenty times, opening up all the relevant objects
;; as maps
;;

(defn generate-object-structure-file
  []
  (let [bc (...get-object...)
        obj (reduce
              (fn [ob keys]
                (apply
                  bean-expand
                  (cons ob keys)))
              bc
              [[:master]
               [:suspense]
               [:suspense :suspenseRecord]
               [:master :beneficiaries]
               [:master :subscriberRecord]
               [:master :dependents]
               [:master :address]
               [:master :coverage]
               [:suspense :suspenseRecord :rateInformation]
               [:suspense :suspenseRecord :zipCode]
               [:suspense :suspenseRecord :beneficiaryData]
               [:suspense :suspenseRecord :beneficiaryData 1]
               [:suspense :suspenseRecord :suspenseInformation]
               [:suspense :suspenseRecord :dependentData]
               [:suspense :suspenseRecord :dependentData 1]
               [:master :beneficiaries :beneficiaryData]
               [:master :beneficiaries :beneficiaryData 1]
               [:master :dependents :dependentData]
               [:master :dependents :dependentData 1]
               [:master :address :zipCode]
               [:master :coverage :rate_information]])]
    (spit-it obj)))