tcoupland

before
Exception: java.lang.NullPointerException: null
                              core.clj:10 compojur-learning.core/logging[fn]
                             Var.java:401 clojure.lang.Var.invoke

tcoupland

(ns compojur-learning.core
  (:use compojure.core))

(defroutes handler
  (GET "/" [] (println "middle") {:status 200}))

(defn logging [chain] (fn [req] (
                                 (println "before")
                                 (chain req)
                                 (println "after"))))

tcoupland

(ns compojur-learning.core
  (:use compojure.core))

(defroutes handler
  (GET "/" [] (println "middle") {:status 200}))

(def app (-> handler))

tcoupland

public class NeedVistorPattern {
		
	public static void main(String[] args){		
		SpaceShip ship = new BigSpaceShip();
		SpaceShipLauncher launcher = new SpaceShipLauncher();
		
		launcher.launch(ship);	
	}
	
	private static class SpaceShipLauncher{

tcoupland

SpaceShip ship = new BigSpaceShip();
LauncherSystem launcher = new LauncherSystem();

launcher.launch(ship);				

class LauncherSystem{
	public void launch(SpaceShip ship){
		Launcher launcher = new Launcher();
		launcher.launch(ship);
	}