url string -> java.net.URL conversion fun!

src/toascii/util.clj

@@ -1,6 +1,8 @@
 (ns toascii.util
+  (:import (java.net URL))
   (:require [clojure.string :as str]
-            [clojure.stacktrace :refer [print-stack-trace]]))
+            [clojure.stacktrace :refer [print-stack-trace]]
+            [cemerick.url :as url]))
 
 (defn get-filename-without-ext [^String filename]
   (let [idx (.lastIndexOf filename ".")]
@@ -17,3 +19,44 @@
   (format "%s %s %s [%s] - %s%s"
           timestamp hostname (-> level name str/upper-case) ns (or message "")
           (or (get-throwable-stack-trace throwable) "")))
+
+(defn encode-url-path-components
+  "Gotta love the Java standard library. If you try to create a java.net.URL or java.net.URI using a URL string that
+   has some part of the path component _not_ url encoded already (e.g. space characters instead of %20), then it throws
+   an exception. There is no easy way to URL encode only that part of the URL (you end up fucking up the 'http://' if
+   you use any of the normal URL encoding methods). In addition! If you are accepting URL parameters in the query
+   string, the path component will be decoded (space characters instead of %20) ... so you can't use URL parameters
+   received via the query string directly with a java.net.URL or java.net.URI! wowee!
+
+   This function takes a cemerick.url/URL and is basically a copy of the toString function from that protocol, except
+   that the :path value gets encoded (but we are careful not to fuck up the forward slashes!)"
+  [{:keys [protocol username password host port path query anchor] :as url}]
+  (when url
+    (let [
+          creds (if username (str username ":" password))]
+      (str protocol "://"
+           creds
+           (when creds \@)
+           host
+           (when (and (not= nil port)
+                      (not= -1 port)
+                      (not (and (== port 80) (= protocol "http")))
+                      (not (and (== port 443) (= protocol "https"))))
+             (str ":" port))
+           (when path
+             (as-> path x
+                   (str/split x #"/")
+                   (map url/url-encode x)
+                   (str/join "/" x)))
+           (when (seq query)
+             (str \? (if (string? query)
+                       query
+                       (url/map->query query))))
+           (when anchor (str \# anchor))))))
+
+(defn query-param-url->java-url [^String url]
+  (->> url
+       (url/url)
+       (encode-url-path-components)
+       (str)
+       (URL.)))