如何获取ServletContext中的ring init函数

Question

我正在使用Clojure + Ring构建运行在Glassfish 3上的Web应用程序。 如何才能访问init函数中的ServletContext变量？

Answer 1

ServletContext（如果有）在请求映射中可用。我发现查看:context, :servlet-context和:servlet-context-path的值很有用。下面是我用来确定路径的一个小型环形中间件：

(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))