Scala2.8 HelloWorld程序ClassNotFoundException
Scala2.8 HelloWorld程序ClassNotFoundException
提问于 2015-07-24 11:37:06
我正在尝试运行一个scala程序，
class HelloWorld {
var myField = 0;
def getMyField() : Int = {
return this.myField;
}
}即使程序名为HelloWorld.scala，我仍然得到一个ClassNotFoundException
以下是完整错误
Exception in thread "main" java.lang.ClassNotFoundException: HelloWorld
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:190)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:122)好的，看一下scala http://www.scala-lang.org/documentation/getting-started.html的文档。
我把代码改成这样，
object HelloWorld {
def main(args: Array[String]) {
println("Hello, world!")
}
}这就是现在的错误
Information:24/7/15 10:55 AM - Compilation completed with 1 error and 7 warnings in 2s 32ms
Error:scalac: Error: org.jetbrains.jps.incremental.scala.remote.ServerException
Error compiling sbt component 'compiler-interface-2.8.0.final-51.0'
at sbt.compiler.AnalyzingCompiler$$anonfun$compileSources$1$$anonfun$apply$2.apply(AnalyzingCompiler.scala:145)
at sbt.compiler.AnalyzingCompiler$$anonfun$compileSources$1$$anonfun$apply$2.apply(AnalyzingCompiler.scala:142)
at sbt.IO$.withTemporaryDirectory(IO.scala:285)
at sbt.compiler.AnalyzingCompiler$$anonfun$compileSources$1.apply(AnalyzingCompiler.scala:142)
at sbt.compiler.AnalyzingCompiler$$anonfun$compileSources$1.apply(AnalyzingCompiler.scala:139)
at sbt.IO$.withTemporaryDirectory(IO.scala:285)
at sbt.compiler.AnalyzingCompiler$.compileSources(AnalyzingCompiler.scala:139)
at sbt.compiler.IC$.compileInterfaceJar(IncrementalCompiler.scala:33)
at org.jetbrains.jps.incremental.scala.local.CompilerFactoryImpl$.org$jetbrains$jps$incremental$scala$local$CompilerFactoryImpl$$getOrCompileInterfaceJar(CompilerFactoryImpl.scala:87)
at org.jetbrains.jps.incremental.scala.local.CompilerFactoryImpl$$anonfun$getScalac$1.apply(CompilerFactoryImpl.scala:44)
at org.jetbrains.jps.incremental.scala.local.CompilerFactoryImpl$$anonfun$getScalac$1.apply(CompilerFactoryImpl.scala:43)
at scala.Option.map(Option.scala:145)
at org.jetbrains.jps.incremental.scala.local.CompilerFactoryImpl.getScalac(CompilerFactoryImpl.scala:43)
at org.jetbrains.jps.incremental.scala.local.CompilerFactoryImpl.createCompiler(CompilerFactoryImpl.scala:22)
at org.jetbrains.jps.incremental.scala.local.CachingFactory$$anonfun$createCompiler$1.apply(CachingFactory.scala:24)
at org.jetbrains.jps.incremental.scala.local.CachingFactory$$anonfun$createCompiler$1.apply(CachingFactory.scala:24)
at org.jetbrains.jps.incremental.scala.local.Cache$$anonfun$getOrUpdate$2.apply(Cache.scala:20)
at scala.Option.getOrElse(Option.scala:120)
at org.jetbrains.jps.incremental.scala.local.Cache.getOrUpdate(Cache.scala:19)
at org.jetbrains.jps.incremental.scala.local.CachingFactory.createCompiler(CachingFactory.scala:23)
at org.jetbrains.jps.incremental.scala.local.LocalServer.compile(LocalServer.scala:22)
at org.jetbrains.jps.incremental.scala.remote.Main$.make(Main.scala:62)
at org.jetbrains.jps.incremental.scala.remote.Main$.nailMain(Main.scala:20)
at org.jetbrains.jps.incremental.scala.remote.Main.nailMain(Main.scala)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at com.martiansoftware.nailgun.NGSession.run(NGSession.java:319)
Warning:scalac: /tmp/sbt_20e2573f/compiler-interface-sources/CompilerInterface.scala:161: error: object creation impossible, since method registerTopLevelSym in trait GlobalCompat of type (sym: this.Symbol)Unit is not defined
Warning:scalac: new Compiler() with RangePositions // unnecessary in 2.11
Warning:scalac: ^
Warning:scalac: /tmp/sbt_20e2573f/compiler-interface-sources/CompilerInterface.scala:165: error: class Compiler needs to be abstract, since method registerTopLevelSym in trait GlobalCompat of type (sym: Compiler.this.Symbol)Unit is not defined
Warning:scalac: class Compiler extends CallbackGlobal(command.settings, dreporter, output)
Warning:scalac: ^
Warning:scalac: two errors found回答 3
Stack Overflow用户
发布于 2015-07-24 12:06:01
你的错误不是在代码中，而是在你试图运行代码的方式上。
我将代码加载到REPL中，没有得到任何错误。我将代码加载到IntelliJ中，得到了许多样式警告，但没有出现错误。我编译了代码并从命令行运行：
%> java HelloWorld
Error: Main method not found in class HelloWorld, please define the
main method as:
public static void main(String[] args)这是人们应该预料到的。
Stack Overflow用户
发布于 2015-07-24 12:52:06
我不明白你是如何运行你的程序的。因为我没有收到任何错误。让我与您分享一种运行代码片段的简单方法。
class HelloWorld{
var myField = 0;
def getMyField() : Int = {
return this.myField;
}
}
object Test extends App{
println(new HelloWorld().getMyField())
}通过在测试中单击鼠标右键尝试运行Test对象。希望我能帮上忙。
Stack Overflow用户
发布于 2018-10-11 02:11:36
假设您正在运行IntelliJ，请尝试构建项目(CTRL+F9)，然后运行它。我也有同样的问题，这对我很有效。
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/31601772
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