That seems to be right. I just tested it and that seem to fix the problem. I am confused about why Clojure appears to give the wrong line number? Is there often a difference between the line number Emacs gives and line number in the stack trace?
On Tuesday, August 28, 2012 10:34:16 PM UTC-4, Mark Rathwell wrote: > > See [1]. > > Valid ServerSocket constructors: > > ServerSocket() > ServerSocket(int) > ServerSocket(int,int) > ServerSocket(int,int,InetAddress) > > Your code is trying: > > ServerSocket(int,string) > > [1] > http://docs.oracle.com/javase/1.4.2/docs/api/java/net/ServerSocket.html > > > On Tue, Aug 28, 2012 at 8:25 PM, larry google groups > <lawrenc...@gmail.com<javascript:> > > wrote: > >> I apologize about the beginner questions. I am new to Clojure. >> >> If I do this: >> >> (defn run-server [port what-to-do] >> (let [server-socket (ServerSocket. port "localhost")] >> (while (not (. server-socket isClosed)) >> (listen-and-respond server-socket what-to-do)))) >> >> (defn -main [& args] >> (let [port (Integer/parseInt (first args)) >> service (symbol (second args))] >> (println "Server is starting") >> (println "port: " port) >> (println (second args)) >> (println (symbol (second args))) >> (println "service: " service) >> (run-server port service))) >> >> And on the command line I call it like: >> >> java -jar who-is-logged-in-1.0-standalone.jar 3456 "who-is-here-now" >> >> This prints out: >> >> Server is starting >> port: 3456 >> who-is-here-now >> who-is-here-now >> service: who-is-here-now >> >> but then I get this error: >> >> Exception in thread "main" java.lang.ClassCastException: java.lang.String >> cannot be cast to java.lang.Number >> at who_is_logged_in.core$run_server.invoke(core.clj:27) >> >> Line 27 is: >> >> (defn run-server [port what-to-do] >> >> The only way I can read the error message is to think that the code is >> trying to assign the value of what-to-do to the (integer) "port". >> >> What have I done wrong? >> >> >> >> >> On Tuesday, August 28, 2012 12:47:44 PM UTC-4, larry google groups wrote: >>> >>> >Command line arguments that are not strings need to be converted >>> > prior to use by your main function. >>> >>> That makes sense, I need to cast it to a symbol, yes? I have a problem >>> with that though. At the REPL I tried something like this: >>> >>> (def hey (resolve (symbol what-to-do))) >>> >>> which worked great at the REPL, but in my code I get "nil" returned from >>> resolve. If I do this: >>> >>> (defn -main [& args] >>> (let [port (Integer/parseInt (first args)) >>> service (resolve (symbol (second args)))] >>> (println "Server is starting") >>> (println "port: " port) >>> (println (second args)) >>> (println (symbol (second args))) >>> (println "service: " service) >>> (run-server port service))) >>> >>> And call it like this: >>> >>> java -jar who-is-logged-in-1.0.0-**SNAPSHOT-standalone.jar 3456 >>> "who-is-here-now" >>> >>> Everything looks correct till the final line when I get "nil": >>> >>> Server is starting >>> port: 3456 >>> who-is-here-now >>> who-is-here-now >>> service: nil >>> >>> >>> >>> >>> >>> >>> >>> >>> On Tuesday, August 28, 2012 6:53:24 AM UTC-4, Jon_Boone wrote: >>>> >>>> Command line arguments that are not strings need to be converted prior >>>> to use by your main function. >>>> >>>> Look at the code for the port number and do the same for the service. >>>> >>>> --jon >>>> >>>> >>>> On Aug 28, 2012, at 2:42, larry google groups <lawrenc...@gmail.com> >>>> wrote: >>>> >>>> >>>> So, this started when I read Keith Swallow's article on a simple web >>>> server: >>>> >>>> http://keithcelt.com/a-simple-**web-server-in-clojure<http://keithcelt.com/a-simple-web-server-in-clojure> >>>> >>>> I took his code and ran "lein new" to create a new project and I copy >>>> and pasted his code to core.clj and made some minor adjustments, adding >>>> gen-class and main so I could run this from the command line. My main >>>> function looked like this: >>>> >>>> (defn -main [& args] >>>> (let [port (Integer/parseInt (first args))] >>>> (println "Server is starting") >>>> (run-server port echo))) >>>> >>>> Which called his function: >>>> >>>> (defn run-server [port service] >>>> (let [server-socket (create-socket port)] >>>> (while (not (. server-socket isClosed)) >>>> >>>> (listen-and-respond server-socket service)))) >>>> >>>> I compiled that and ran "lein uberjar" and then ran it from the command >>>> line and it worked great. >>>> >>>> Then, to make it slightly more flexible, I wanted to hand in the name >>>> of the service from the command line. So I made a minor change: >>>> >>>> >>>> (defn run-server [port what-to-do] >>>> (let [server-socket (ServerSocket. "localhost" port)] >>>> (while (not (. server-socket isClosed)) >>>> (listen-and-respond server-socket what-to-do)))) >>>> >>>> (defn -main [& args] >>>> (let [port (Integer/parseInt (first args)) >>>> service (second args)] >>>> (println "Server is starting") >>>> (println "port: " port) >>>> (println "service: " service) >>>> (run-server port service))) >>>> >>>> I compiled this and ran it. And now this line: >>>> >>>> (defn run-server [port what-to-do] >>>> >>>> Gets this error: >>>> >>>> Exception in thread "main" java.lang.ClassCastException: >>>> java.lang.String cannot be cast to java.lang.Number >>>> at who_is_logged_in.core$run_**server.invoke(core.clj:27) >>>> >>>> I'm calling it from the command line with: >>>> >>>> java -jar who-is-logged-in-1.0.0-**SNAPSHOT-standalone.jar 3456 >>>> who-is-here-now >>>> >>>> I also tried putting the service name in quotes: >>>> >>>> java -jar who-is-logged-in-1.0.0-**SNAPSHOT-standalone.jar 3456 >>>> "who-is-here-now" >>>> >>>> Can anyone tell me what is wrong? Why does Clojure think I'm trying to >>>> cast "who-is-here-now" to a number? >>>> >>>> >>>> >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "Clojure" group. >>>> To post to this group, send email to clo...@googlegroups.com >>>> Note that posts from new members are moderated - please be patient with >>>> your first post. >>>> To unsubscribe from this group, send email to >>>> clojure+u...@googlegroups.com >>>> For more options, visit this group at >>>> http://groups.google.com/**group/clojure?hl=en<http://groups.google.com/group/clojure?hl=en> >>>> >>>> -- >> You received this message because you are subscribed to the Google >> Groups "Clojure" group. >> To post to this group, send email to clo...@googlegroups.com<javascript:> >> Note that posts from new members are moderated - please be patient with >> your first post. >> To unsubscribe from this group, send email to >> clojure+u...@googlegroups.com <javascript:> >> For more options, visit this group at >> http://groups.google.com/group/clojure?hl=en >> > > -- You received this message because you are subscribed to the Google Groups "Clojure" group. 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