CODEWITHSUNDEEP
javaclojurefile-not-foundfunction-parameter
trzczy
trzczy

Reputation: 1501

"java.io.FileNotFoundException" error related to a port number 8080 that is a function patameter

I am practising a Clojure tutorial "Basic Web Development" http://clojure-doc.org/articles/tutorials/basic_web_development.html

In the end, I am facing a problem. When I execute 

$ java -jar target/clojure-webapp-0.1.0-SNAPSHOT-standalone.jar 8080

an error is occurring

Exception in thread "main" java.io.FileNotFoundException: 8080 (No such file or directory)

So the port number is parsed as a file name of a file that cannot be found.

I am not familiar with Java, but I think the situation is clear. The port number is a typical function parameter, not a file name. Please explain me it and tell how to fix it. More details:

s@lokal:~/Dropbox/clojure-webapp$ lein uberjar
Created /home/s/Dropbox/clojure-webapp/target/clojure-webapp-0.1.0-SNAPSHOT.jar
Created /home/s/Dropbox/clojure-webapp/target/clojure-webapp-0.1.0-SNAPSHOT-standalone.jar
s@lokal:~/Dropbox/clojure-webapp$ cat ~/Dropbox/clojure-webapp/src/clojure_webapp/handler.clj 
(ns clojure-webapp.handler
  (:require [clojure-webapp.views :as views]
            [compojure.core :refer :all]
            [compojure.route :as route]
            [ring.adapter.jetty :as jetty]
            [ring.middleware.defaults :refer [wrap-defaults site-defaults]])
  (:gen-class))
(defroutes app-routes ; replace the generated app-routes with this
  (GET "/"
       []
       (views/home-page))
  (GET "/add-location"
       []
       (views/add-location-page))
  (POST "/add-location"
        {params :params}
        (views/add-location-results-page params))
  (GET "/location/:loc-id"
       [loc-id]
       (views/location-page loc-id))
  (GET "/all-locations"
       []
       (views/all-locations-page))
  (route/resources "/")
  (route/not-found "Not Found"))

(def app
  (wrap-defaults app-routes site-defaults))


(defn -main
  [& [port]]
  (let [port (Integer. (or port
                           (System/getenv "PORT")
                           5000))]
    (jetty/run-jetty #'app {:port  port
                            :join? false})))
s@lokal:~/Dropbox/clojure-webapp$ java -jar target/clojure-webapp-0.1.0-SNAPSHOT-standalone.jar 8080
Exception in thread "main" java.io.FileNotFoundException: 8080 (No such file or directory)
    at java.base/java.io.FileInputStream.open0(Native Method)
    at java.base/java.io.FileInputStream.open(FileInputStream.java:219)
    at java.base/java.io.FileInputStream.<init>(FileInputStream.java:157)
    at java.base/java.io.FileInputStream.<init>(FileInputStream.java:112)
    at clojure.lang.Compiler.loadFile(Compiler.java:7449)
    at clojure.main$load_script.invokeStatic(main.clj:278)
    at clojure.main$script_opt.invokeStatic(main.clj:338)
    at clojure.main$script_opt.invoke(main.clj:333)
    at clojure.main$main.invokeStatic(main.clj:424)
    at clojure.main$main.doInvoke(main.clj:387)
    at clojure.lang.RestFn.applyTo(RestFn.java:137)
    at clojure.lang.Var.applyTo(Var.java:702)
    at clojure.main.main(main.java:37)
s@lokal:~/Dropbox/clojure-webapp$

Upvotes: 0

Views: 368

Answers (1)

Alan Thompson
Alan Thompson

Reputation: 29984

This tutorial is a bit old, I believe. IMHO you might be happier using Pedestal instead of Ring anyway. You can find a "Hello World" tutorial here:

I have some working code that is the result of the tutorial, which you can clone from here:

[email protected]:cloojure/pedestal-tutorial.git

In a terminal window, start the code via:

> lein run

Then navigate your browser to:

http://localhost:8890/echo                   ; demo/test route
http://localhost:8890/greet                  ; generic greeting
http://localhost:8890/greet?name=Bob         ; normal greeting
http://localhost:8890/greet?name=Voldemort   ; unmentionable!

If you want to stick to Ring/Compojure, another option is the Clojure Cookbook, which has examples. It is available both in print (recommended) or online:

Here is another great book:

Upvotes: 1

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