gen-class-example.clj

(ns foobar
  (:gen-class
   :name Foobar
   :methods [[say-hello [] void]]))

(defn -say-hello []
  (println "Saying hello from Clojure World!"))

Exception in thread "main" java.lang.IllegalArgumentException: Not a valid method name: say-hello (foobar.clj:1)
        at clojure.lang.Compiler.analyzeSeq(Compiler.java:5376)
        at clojure.lang.Compiler.analyze(Compiler.java:5190)
        at clojure.lang.Compiler.analyze(Compiler.java:5151)
        at clojure.lang.Compiler$BodyExpr$Parser.parse(Compiler.java:4670)
        at clojure.lang.Compiler$TryExpr$Parser.parse(Compiler.java:1833)
        at clojure.lang.Compiler.analyzeSeq(Compiler.java:5369)
        at clojure.lang.Compiler.analyze(Compiler.java:5190)
        at clojure.lang.Compiler.analyze(Compiler.java:5151)
        at clojure.lang.Compiler$BodyExpr$Parser.parse(Compiler.java:4670)
        at clojure.lang.Compiler$FnMethod.parse(Compiler.java:4328)
        at clojure.lang.Compiler$FnExpr.parse(Compiler.java:3173)
        at clojure.lang.Compiler.analyzeSeq(Compiler.java:5367)
        at clojure.lang.Compiler.analyze(Compiler.java:5190)
        at clojure.lang.Compiler.analyzeSeq(Compiler.java:5357)
        at clojure.lang.Compiler.analyze(Compiler.java:5190)
        at clojure.lang.Compiler.analyze(Compiler.java:5151)
        at clojure.lang.Compiler$InvokeExpr.parse(Compiler.java:3036)
        at clojure.lang.Compiler.analyzeSeq(Compiler.java:5371)
        at clojure.lang.Compiler.analyze(Compiler.java:5190)
        at clojure.lang.Compiler.analyze(Compiler.java:5151)
        at clojure.lang.Compiler.compile1(Compiler.java:5928)
        at clojure.lang.Compiler.compile1(Compiler.java:5923)
        at clojure.lang.Compiler.compile(Compiler.java:5992)
        at clojure.lang.RT.compile(RT.java:368)
        at clojure.lang.RT.load(RT.java:407)
        at clojure.lang.RT.load(RT.java:381)
        at clojure.core$load$fn__4511.invoke(core.clj:4905)
        at clojure.core$load.doInvoke(core.clj:4904)
        at clojure.lang.RestFn.invoke(RestFn.java:409)
        at clojure.core$load_one.invoke(core.clj:4729)
        at clojure.core$compile$fn__4516.invoke(core.clj:4916)
        at clojure.core$compile.invoke(core.clj:4915)
        at user$eval7.invoke(NO_SOURCE_FILE:1)
        at clojure.lang.Compiler.eval(Compiler.java:5424)
        at clojure.lang.Compiler.eval(Compiler.java:5415)
        at clojure.lang.Compiler.eval(Compiler.java:5391)
        at clojure.core$eval.invoke(core.clj:2382)
        at clojure.main$eval_opt.invoke(main.clj:235)
        at clojure.main$initialize.invoke(main.clj:254)
        at clojure.main$null_opt.invoke(main.clj:279)
        at clojure.main$main.doInvoke(main.clj:354)
        at clojure.lang.RestFn.invoke(RestFn.java:422)
        at clojure.lang.Var.invoke(Var.java:369)
        at clojure.lang.AFn.applyToHelper(AFn.java:165)
        at clojure.lang.Var.applyTo(Var.java:482)
        at clojure.main.main(main.java:37)
Caused by: java.lang.IllegalArgumentException: Not a valid method name: say-hello
        at clojure.core$validate_generate_class_options.invoke(genclass.clj:101)
        at clojure.core$generate_class.invoke(genclass.clj:104)
        at clojure.core$gen_class.doInvoke(genclass.clj:614)
        at clojure.lang.RestFn.invoke(RestFn.java:706)
        at clojure.lang.Var.invoke(Var.java:415)
        at clojure.lang.AFn.applyToHelper(AFn.java:250)
        at clojure.lang.Var.applyTo(Var.java:482)
        at clojure.lang.Compiler.macroexpand1(Compiler.java:5286)
        at clojure.lang.Compiler.analyzeSeq(Compiler.java:5355)
        ... 45 more