如何獲取ServletContext中的ring init函數

Question

我正在使用Clojure + Ring構建運行在Glassfish 3上的Web應用程序。 如何才能訪問init函數中的ServletContext變量？

Answer 1

ServletContext（如果有）在請求映射中可用。我發現查看:context, :servlet-context和:servlet-context-path的值很有用。下面是我用來確定路徑的一個小型環形中間件：

(def ^:dynamic *app-context* nil) 

(defn wrap-context [handler] 
(fn [request] 
    (when-let [context (:context request)] 
    (logging/debug (str "Request with context " context))) 
    (when-let [pathdebug (:path-debug request)] 
    (logging/debug (str "Request with path-debug " pathdebug))) 
    (when-let [servlet-context (:servlet-context request)] 
    (logging/debug (str "Request with servlet-context " servlet-context))) 
    (when-let [servlet-context-path (:servlet-context-path request)] 
    (logging/debug (str "Request with servlet-context-path " servlet-context-path))) 
    (binding [*app-context* (str (:context request) "/")] 
    (logging/debug (str "Using appcontext " *app-context*)) 
    (-> request 
     handler)))) 

(defn url-in-context [url] 
    (str *app-context* url))