Ring Hello

gistfile1.clj

(defn app [req]
  {:status  200
   :headers {"Content-Type" "text/html"}
   :body    (str "Hi from " (:server-name req))})

(use 'ring.adapter.jetty)

(run-jetty app {:port 8080})

HelloServlet.java

import javax.servlet.http.*;
import javax.servlet.*;

public class HelloServlet extends HttpServlet {
  public void doGet (HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {
     res.setStatus(200);
     res.setContentType("text/plain");
     PrintWriter out = res.getWriter();
     out.println("Hello world");
     out.close();
  }
} 

repl.clj

user> (app {:server-name "localhost"})
{:status 200, :headers {"Content-Type" "text/html"}, :body "Hi from localhost"}
user> (= {:status 200, :headers {"Content-Type" "text/html"}, :body "Hi from localhost"} (app {:server-name "localhost"}))
true