Clojure, Servlet and JWT

Question

EDIT: For a working sample, take a look at this demo project.

Disclaimer: I'm a total noob in building java web applications.

I'm trying to use JWT with Clojure but I simply don't know how deal with this "servlet" thing. So far, my idea was:

1. Create a WApplication with a "Hello World" form.

   (defn make-hello-app [env]
     (let [wapp (WApplication. env)
           root (.getRoot wapp)]
       (.setTitle wapp "Hello world")
       (.addWidget root (WText. "Hello!!!!"))
       wapp))
   

2. Create a servlet, inherited from WtServlet.

   (def servlet
     (proxy [WtServlet] []
       (createApplication [env]
         (make-hello-app env))))
   

3. Start jetty and use the servlet. This is what I don't know how to do. So far, this was my best shot:

   (ns jwttest.core
     (:use compojure.core)
     (:use ring.adapter.jetty)
     (:import (org.eclipse.jetty.server Server))
     (:import (eu.webtoolkit.jwt WApplication WEnvironment WtServlet WText WPushButton WLineEdit WBreak)))
   
   ;; (the funcions above were defined here)
   
   ;; create a jetty server
   (defn create-a-jetty-server []
     (let [connector (doto (SelectChannelConnector.)
                           (.setPort 8080)
                           (.setHost "localhost"))
        server (doto (Server.)
                     (.addConnector connector)
                     (.setSendDateHeader true))]
        server))
   
    ;; start the application
    (defn start-the-app []
      (let [server (create-a-jetty-server)]
         ;; ???? .addServlet ? How?
         (.start server)))
   

In my project.clj I have:

[org.clojure/clojure "1.4.0"]
[eu.webtoolkit/jwt "3.2.0"]
[compojure "1.1.1"]
[ring "1.1.2"]

I know ring can create a servlet from a handler, but in this case I already have a servlet so... what should I do to run this?

Note: I'm basing my code on this very old post made in 2009.

Answer 1

I dug through some of the Jetty API and the Ring/Noir jetty handling code and here's a summary of what I found (and haven't had a chance to test)

• Jetty Server has a "setHandler" method which takes a handler (thanks Ring)
• There is a ServletHandler class which looks like it fits into the above and which has a number of addServlet like methods which look like they do what you need them to.

You should be able to set the handler to a Servlet handler and go from there.