Ich habe einen guten Schlag bekommen, als ich Hello World mit Scala ausprobiert habe (Objekt java.lang.Object im Compilerspiegel nicht gefunden.)
TL;DR
Das Durchschnittsgehalt von Scala ~~ war sehr hoch, also interessierte ich mich für ~~, also beschloss ich, es zu versuchen, und beschloss, in meiner Freizeit ein Projekt für Hello World zu machen.
Durchschnittliches Jahreseinkommen nach Sprache
Nun, ich mache Installationssysteme an verschiedenen Orten, also ist es jetzt besser.
Es sollte kein Problem geben, wenn Sie das beliebteste Framework verwenden.
Nun, sofort.
console
$ activator new my-first-app play-scala
Ohne Probleme abgeschlossen (ich habe das Gefühl, dass WARNING out war ...)
console
$ cd my-first-app/
$ activator
WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by activator.ActivatorProxyAuthenticator$ (file:/Users/(username)/.sbt/boot/scala-2.11.8/com.typesafe.activator/activator-launcher/1.3.12/activator-launcher-1.3.12.jar) to field java.net.Authenticator.theAuthenticator
WARNING: Please consider reporting this to the maintainers of activator.ActivatorProxyAuthenticator$
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release
error: error while loading package, Missing dependency 'object java.lang.Object in compiler mirror', required by /Users/(username)/.sbt/boot/scala-2.10.6/lib/scala-library.jar(scala/package.class)
error: error while loading package, Missing dependency 'object java.lang.Object in compiler mirror', required by /Users/(username)/.sbt/boot/scala-2.10.6/lib/scala-library.jar(scala/runtime/package.class)
scala.reflect.internal.MissingRequirementError: object java.lang.Object in compiler mirror not found.
at scala.reflect.internal.MissingRequirementError$.signal(MissingRequirementError.scala:16)
at scala.reflect.internal.MissingRequirementError$.notFound(MissingRequirementError.scala:17)
at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:48)
at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:40)
at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:40)
at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:61)
at scala.reflect.internal.Mirrors$RootsBase.getClassByName(Mirrors.scala:99)
at scala.reflect.internal.Mirrors$RootsBase.getRequiredClass(Mirrors.scala:102)
at scala.reflect.internal.Definitions$DefinitionsClass.ObjectClass$lzycompute(Definitions.scala:264)
at scala.reflect.internal.Definitions$DefinitionsClass.ObjectClass(Definitions.scala:264)
at scala.reflect.internal.Definitions$DefinitionsClass.AnyRefClass$lzycompute(Definitions.scala:263)
at scala.reflect.internal.Definitions$DefinitionsClass.AnyRefClass(Definitions.scala:263)
at scala.reflect.internal.Definitions$DefinitionsClass.specialPolyClass(Definitions.scala:1120)
at scala.reflect.internal.Definitions$DefinitionsClass.RepeatedParamClass$lzycompute(Definitions.scala:407)
at scala.reflect.internal.Definitions$DefinitionsClass.RepeatedParamClass(Definitions.scala:407)
at scala.reflect.internal.Definitions$DefinitionsClass.syntheticCoreClasses$lzycompute(Definitions.scala:1154)
at scala.reflect.internal.Definitions$DefinitionsClass.syntheticCoreClasses(Definitions.scala:1152)
at scala.reflect.internal.Definitions$DefinitionsClass.symbolsNotPresentInBytecode$lzycompute(Definitions.scala:1196)
at scala.reflect.internal.Definitions$DefinitionsClass.symbolsNotPresentInBytecode(Definitions.scala:1196)
at scala.reflect.internal.Definitions$DefinitionsClass.init(Definitions.scala:1261)
at scala.tools.nsc.Global$Run.<init>(Global.scala:1290)
at sbt.compiler.Eval$$anon$1.<init>(Eval.scala:141)
at sbt.compiler.Eval.run$lzycompute$1(Eval.scala:141)
at sbt.compiler.Eval.run$1(Eval.scala:141)
at sbt.compiler.Eval.unlinkAll$1(Eval.scala:144)
at sbt.compiler.Eval.evalCommon(Eval.scala:153)
at sbt.compiler.Eval.eval(Eval.scala:96)
at sbt.EvaluateConfigurations$.evaluateDslEntry(EvaluateConfigurations.scala:177)
at sbt.EvaluateConfigurations$$anonfun$9.apply(EvaluateConfigurations.scala:117)
at sbt.EvaluateConfigurations$$anonfun$9.apply(EvaluateConfigurations.scala:115)
at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244)
at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244)
at scala.collection.immutable.List.foreach(List.scala:318)
at scala.collection.TraversableLike$class.map(TraversableLike.scala:244)
at scala.collection.AbstractTraversable.map(Traversable.scala:105)
at sbt.EvaluateConfigurations$.evaluateSbtFile(EvaluateConfigurations.scala:115)
at sbt.Load$.sbt$Load$$loadSettingsFile$1(Load.scala:725)
at sbt.Load$$anonfun$sbt$Load$$memoLoadSettingsFile$1$1.apply(Load.scala:731)
at sbt.Load$$anonfun$sbt$Load$$memoLoadSettingsFile$1$1.apply(Load.scala:730)
at scala.collection.MapLike$class.getOrElse(MapLike.scala:128)
at scala.collection.AbstractMap.getOrElse(Map.scala:58)
at sbt.Load$.sbt$Load$$memoLoadSettingsFile$1(Load.scala:730)
at sbt.Load$$anonfun$loadFiles$1$2.apply(Load.scala:738)
at sbt.Load$$anonfun$loadFiles$1$2.apply(Load.scala:738)
at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244)
at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:244)
at scala.collection.mutable.ResizableArray$class.foreach(ResizableArray.scala:59)
at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:47)
at scala.collection.TraversableLike$class.map(TraversableLike.scala:244)
at scala.collection.AbstractTraversable.map(Traversable.scala:105)
at sbt.Load$.loadFiles$1(Load.scala:738)
at sbt.Load$.discoverProjects(Load.scala:749)
at sbt.Load$.discover$1(Load.scala:555)
at sbt.Load$.loadTransitive(Load.scala:584)
at sbt.Load$.loadProjects$1(Load.scala:452)
at sbt.Load$.loadUnit(Load.scala:456)
at sbt.Load$$anonfun$18$$anonfun$apply$11.apply(Load.scala:291)
at sbt.Load$$anonfun$18$$anonfun$apply$11.apply(Load.scala:291)
at sbt.BuildLoader$$anonfun$componentLoader$1$$anonfun$apply$4$$anonfun$apply$5$$anonfun$apply$6.apply(BuildLoader.scala:91)
at sbt.BuildLoader$$anonfun$componentLoader$1$$anonfun$apply$4$$anonfun$apply$5$$anonfun$apply$6.apply(BuildLoader.scala:90)
at sbt.BuildLoader.apply(BuildLoader.scala:140)
at sbt.Load$.loadAll(Load.scala:344)
at sbt.Load$.loadURI(Load.scala:299)
at sbt.Load$.load(Load.scala:295)
at sbt.Load$.load(Load.scala:286)
at sbt.Load$.apply(Load.scala:140)
at sbt.Load$.buildPluginDefinition(Load.scala:836)
at sbt.Load$.buildPlugins(Load.scala:802)
at sbt.Load$.plugins(Load.scala:790)
at sbt.Load$.loadUnit(Load.scala:441)
at sbt.Load$$anonfun$18$$anonfun$apply$11.apply(Load.scala:291)
at sbt.Load$$anonfun$18$$anonfun$apply$11.apply(Load.scala:291)
at sbt.BuildLoader$$anonfun$componentLoader$1$$anonfun$apply$4$$anonfun$apply$5$$anonfun$apply$6.apply(BuildLoader.scala:91)
at sbt.BuildLoader$$anonfun$componentLoader$1$$anonfun$apply$4$$anonfun$apply$5$$anonfun$apply$6.apply(BuildLoader.scala:90)
at sbt.BuildLoader.apply(BuildLoader.scala:140)
at sbt.Load$.loadAll(Load.scala:344)
at sbt.Load$.loadURI(Load.scala:299)
at sbt.Load$.load(Load.scala:295)
at sbt.Load$.load(Load.scala:286)
at sbt.Load$.apply(Load.scala:140)
at sbt.Load$.defaultLoad(Load.scala:36)
at sbt.BuiltinCommands$.liftedTree1$1(Main.scala:492)
at sbt.BuiltinCommands$.doLoadProject(Main.scala:492)
at sbt.BuiltinCommands$$anonfun$loadProjectImpl$2.apply(Main.scala:484)
at sbt.BuiltinCommands$$anonfun$loadProjectImpl$2.apply(Main.scala:484)
at sbt.Command$$anonfun$applyEffect$1$$anonfun$apply$2.apply(Command.scala:59)
at sbt.Command$$anonfun$applyEffect$1$$anonfun$apply$2.apply(Command.scala:59)
at sbt.Command$$anonfun$applyEffect$2$$anonfun$apply$3.apply(Command.scala:61)
at sbt.Command$$anonfun$applyEffect$2$$anonfun$apply$3.apply(Command.scala:61)
at sbt.Command$.process(Command.scala:93)
at sbt.MainLoop$$anonfun$1$$anonfun$apply$1.apply(MainLoop.scala:96)
at sbt.MainLoop$$anonfun$1$$anonfun$apply$1.apply(MainLoop.scala:96)
at sbt.State$$anon$1.process(State.scala:184)
at sbt.MainLoop$$anonfun$1.apply(MainLoop.scala:96)
at sbt.MainLoop$$anonfun$1.apply(MainLoop.scala:96)
at sbt.ErrorHandling$.wideConvert(ErrorHandling.scala:17)
at sbt.MainLoop$.next(MainLoop.scala:96)
at sbt.MainLoop$.run(MainLoop.scala:89)
at sbt.MainLoop$$anonfun$runWithNewLog$1.apply(MainLoop.scala:68)
at sbt.MainLoop$$anonfun$runWithNewLog$1.apply(MainLoop.scala:63)
at sbt.Using.apply(Using.scala:24)
at sbt.MainLoop$.runWithNewLog(MainLoop.scala:63)
at sbt.MainLoop$.runAndClearLast(MainLoop.scala:46)
at sbt.MainLoop$.runLoggedLoop(MainLoop.scala:30)
at sbt.MainLoop$.runLogged(MainLoop.scala:22)
at sbt.StandardMain$.runManaged(Main.scala:54)
at sbt.xMain.run(Main.scala:29)
at xsbt.boot.Launch$$anonfun$run$1.apply(Launch.scala:109)
at xsbt.boot.Launch$.withContextLoader(Launch.scala:128)
at xsbt.boot.Launch$.run(Launch.scala:109)
at xsbt.boot.Launch$$anonfun$apply$1.apply(Launch.scala:35)
at xsbt.boot.Launch$.launch(Launch.scala:117)
at xsbt.boot.Launch$.apply(Launch.scala:18)
at xsbt.boot.Boot$.runImpl(Boot.scala:41)
at xsbt.boot.Boot$.main(Boot.scala:17)
at xsbt.boot.Boot.main(Boot.scala)
[error] scala.reflect.internal.MissingRequirementError: object java.lang.Object in compiler mirror not found.
[error] Use 'last' for the full log.
Project loading failed: (r)etry, (q)uit, (l)ast, or (i)gnore? q
** Ich habe nicht geschrieben, dass es so herauskommen würde? ** ** **
Es scheint, dass das installierte Java (Java10) nicht das Problem ist () Als ich mit einem Fehler gegoogelt habe, war es schwer zu finden, da nur die Artikel, in denen der Teil "java.lang.Object" zu "scala" wurde, an die Spitze kamen. (Compiler konnte nicht initialisiert werden: Objekt java.lang.Object im Compilerspiegel nicht gefunden ) Java8 sollte also in Ordnung sein, also installieren Sie es.
console
$ brew cask install caskroom/versions/java8
Java8 eingegeben! Also sofort wechseln.
console
$ vi ~/.bashrc
.bashrc
export JAVA_HOME=`/System/Library/Frameworks/JavaVM.framework/Versions/A/Commands/java_home -v “1.8”`
PATH=$JAVA_HOME/bin:$PATH
console
$ source ~/.bashrc
$ activator run
...
...
(Server started, use Ctrl+D to stop and go back to the console...)
Du hast es geschafft. Ich hatte ein großartiges Erfolgserlebnis (ich werfe etwas, das die Ursache zu sein scheint, aber ich machte mir Sorgen um 2 Stunden), aber ich kam, um helloworld zu schreiben, also werde ich es schreiben.
routes
GET /hello controllers.GreetController.index
GreetController.scala
package controllers
import javax.inject._
import play.api._
import play.api.mvc._
@Singleton
class GreetController @Inject() extends Controller {
def index = Action {
Ok("Hello world")
}
}
Zugriff auf [localhost: 9000 / hallo](localhost: 9000 / hallo).
Chissa www
Umgebung
・ Mac OS X EL Capitan 10.11.6 ・ Spielen Sie 2.5.10
console
$ scala -version
Scala code runner version 2.12.5 -- Copyright 2002-2018, LAMP/EPFL and Lightbend, Inc.
$ java -version
java version "1.8.0_172"
Java(TM) SE Runtime Environment (build 1.8.0_172-b11)
Java HotSpot(TM) 64-Bit Server VM (build 25.172-b11, mixed mode)
Referenz
playframework Actions, Controllers and Results
Nachtrag [12.09.2018]
Ich habe einen Titel hinzugefügt, da er nur verwendet werden kann, wenn er vom Fehlerinhalt erfasst wird.
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