Write jar to the :target-path directory.

src/leiningen/clean.clj

@@ -14,7 +14,7 @@ Raise an exception if any deletion fails unless silently is true."
 
 (defn clean [project]
   (println "Cleaning up")
-  (delete-file (str (:root project) "/" (:name project) ".jar") true)
+  (delete-file (str (:target-path project) "/" (:name project) ".jar") true)
   (delete-file (str (:root project) "/" (:name project) "-standalone.jar") true)
   (doseq [d [(:compile-path project)
              (:library-path project)]]

src/leiningen/core.clj

@@ -28,6 +28,8 @@
                                                  (str root# "/test"))
                                   :resources-path (or (:resources-path m#)
                                                       (str root# "/resources"))
+                                  :target-path (or (:target-path m#)
+                                                      (str root# "/target"))
                                   :root root#))))
      (def ~(symbol (name project-name)) project)))
 

src/leiningen/jar.clj

@@ -63,13 +63,18 @@
     (doseq [filespec filespecs]
       (copy-to-jar project jar-os filespec))))
 
+(defn get-jar-filename [project jar-name]
+  (let [target-dir (:target-path project)]
+    (.mkdir (file target-dir))
+    (str target-dir "/"  jar-name)))
+
 (defn jar
   "Create a $PROJECT.jar file containing the compiled .class files as well as
 the source .clj files. If project.clj contains a :main symbol, it will be used
 as the main-class for an executable jar."
   ([project jar-name]
      (compile/compile project)
-     (let [jar-file (str (:root project) "/" jar-name)
+     (let [jar-file (get-jar-filename project jar-name)
            filespecs [{:type :bytes
                        :path (format "meta-inf/maven/%s/%s/pom.xml"
                                      (:group project)