(maint) Fix classpath stuff for Java 9

.travis.yml

@@ -1,9 +1,8 @@
 language: clojure
 jdk:
+  - oraclejdk9
   - oraclejdk8
-  - oraclejdk7
   - openjdk7
-  - openjdk6
 notifications:
   email: false
   hipchat:

project.clj

@@ -23,7 +23,7 @@
                  [cheshire]
 
                  [org.ini4j/ini4j "0.5.2"]
-                 [org.tcrawley/dynapath "0.2.5"]
+                 [org.tcrawley/dynapath "1.0.0"]
                  [digest "1.4.3"]
 
                  ]

src/puppetlabs/kitchensink/classpath.clj

@@ -35,6 +35,15 @@
   [cl]
   (dp/addable-classpath? cl))
 
+(defn- ensure-modifiable-classloader
+  "Check if there is a modifiable classloader in the current hierarchy, and add
+  one if not."
+  []
+  (let [classloader (.. Thread currentThread getContextClassLoader)]
+    (when (not-any? modifiable-classloader? (classloader-hierarchy classloader))
+      (let [new-cl (clojure.lang.DynamicClassLoader. classloader)]
+        (.. Thread currentThread (setContextClassLoader new-cl))))))
+
 (defn add-classpath
   "A corollary to the (deprecated) `add-classpath` in clojure.core. This implementation
    requires a java.io.File or String path to a jar file or directory, and will attempt
@@ -57,6 +66,7 @@
    (if-not (dp/add-classpath-url classloader (.toURL (file jar-or-dir)))
      (throw (IllegalStateException. (str classloader " is not a modifiable classloader")))))
   ([jar-or-dir]
+   (ensure-modifiable-classloader)
    (let [classloaders (classloader-hierarchy)]
      (if-let [cl (last (filter modifiable-classloader? classloaders))]
        (add-classpath jar-or-dir cl)

test/puppetlabs/kitchensink/classpath_test.clj

@@ -4,16 +4,14 @@
   (:import (java.net URL)))
 
 (deftest with-additional-classpath-entries-test
-  (let [paths ["/foo" "/bar"]
-        get-urls #(into #{}
-                        (.getURLs (.getContextClassLoader (Thread/currentThread))))]
+  (let [paths ["classpath-test"]
+        get-resource #(-> (Thread/currentThread)
+                          .getContextClassLoader
+                          (.getResource "does-not-exist-anywhere-else"))]
     (with-additional-classpath-entries
       paths
-      (testing "classloader now includes the new paths"
-        (let [urls (get-urls)]
-          (is (contains? urls (URL. "file:/foo")))
-          (is (contains? urls (URL. "file:/bar"))))))
-    (testing "classloader has been restored to its previous state"
-      (let [urls (get-urls)]
-        (is (not (contains? urls (URL. "file:/foo"))))
-        (is (not (contains? urls (URL. "file:/bar"))))))))
+      (testing "classloader now includes the new path"
+        (is (get-resource))))
+
+    (testing "classloader no longer includes the new path"
+      (is (not (get-resource))))))