本文介绍了使用 ScalaTest 时出现 java.lang.NoSuchFieldError的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我在使用 ScalaTest 时遇到了一个很难调试的错误.奇怪的是，当我的程序没有 Main 对象时似乎会发生这种情况，但当它有 Main 对象时则不会.我的代码实际上只是使用带有多态方法的类型类从列表中获取切片，看起来像这样(对于稍微冗长的示例，我已经尽可能地减少了它):
I'm getting a quite-hard-to-debug error when using ScalaTest. Oddly this seems to occur when my program has no Main object, but not when it does have a Main object. My code is really just using a typeclass with a polymorphic method to get a slice from a list, and looks like this (apologies for the slightly verbose example, I've reduced it down as much as I can):
package sportarray
object ArrayDefs {
abstract class IsArr[A, I0, DT] {
def getElem(self: A, i: Int): DT
def getSlice[R](self: A, r: R)(implicit sliceTc: IsSlice[R]): sliceTc.Out = sliceTc.getSlice(self, r)
trait IsSlice[R] {
type Out
def getSlice(self: A, ref: R): Out
}
object IsSlice {
implicit val iLocTCForInt = new IsSlice[Int] {
type Out = DT
def getSlice(self: A, ref: Int): Out = getElem(self, ref)
}
implicit val iLocTCForList = new IsSlice[List[Int]] {
type Out = List[DT]
def getSlice(self: A, ref: List[Int]): Out = ref.map(getElem(self, _))
}
}
}
object IsArrSyntax {
implicit class IsArrOps[A, I0, T](self: A)(implicit
tc1d: IsArr[A, I0, T]
) {
def getElem(i: Int) = tc1d.getElem(self, i)
def getSlice[R](r: R)(implicit sliceTc: tc1d.IsSlice[R]) = tc1d.getSlice(self, r)
}
}
}
object ListOfListsObj {
import ArrayDefs._
case class List1d[I0, T] (
indices: List[I0],
data: List[T],
)
implicit def list1dIs1dSpArr[A, I0, T] =
new IsArr[List1d[I0, T], I0, T] {
def getElem(self: List1d[I0, T], i: Int) = self.data(i)
}
}
我的测试很简单，看起来像这样，在它自己的测试目录中的文件中:
My test is simple and looks like this, in its own file in the test directory:
package sportarray
import org.scalatest.flatspec.AnyFlatSpec
import org.scalatest.matchers.should.Matchers
class ArraySpec extends AnyFlatSpec with Matchers {
"List" should "act as an array" in {
import ArrayDefs._
import ArrayDefs.IsArrSyntax._
import ListOfListsObj._
val list1d = List1d[Int, Double](List(1,2,3), List(1.0, 2.0, 3.0))
assert(list1d.getSlice(1) == 2.0)
}
}
如果我sbt test这个代码，我得到以下错误:
If I sbt test this code as it is, I get the following error:
java.lang.NoSuchFieldError: sportarray$ArrayDefs$IsArrSyntax$IsArrOps$$tc1d
at sportarray.ArraySpec.$anonfun$new$1(HelloSpec.scala:12)
at org.scalatest.OutcomeOf.outcomeOf(OutcomeOf.scala:85)
at org.scalatest.OutcomeOf.outcomeOf$(OutcomeOf.scala:83)
at org.scalatest.OutcomeOf$.outcomeOf(OutcomeOf.scala:104)
at org.scalatest.Transformer.apply(Transformer.scala:22)
at org.scalatest.Transformer.apply(Transformer.scala:20)
at org.scalatest.flatspec.AnyFlatSpecLike$$anon$5.apply(AnyFlatSpecLike.scala:1683)
然后我尝试向程序添加一个 Main 类，以查看这是测试的问题，还是代码本身的问题:
I then tried adding a Main class to the program to see if this was a problem with the test, or a problem with the code itself:
object Main extends App {
import ArrayDefs._
import ArrayDefs.IsArrSyntax._
import ListOfListsObj._
val list1d = List1d[Int, Double](List(1,2,3), List(1.0, 2.0, 3.0))
assert(list1d.getSlice(1) == 2.0)
}
如果我sbt run，这很好用，而且奇怪的是，它还允许我毫无问题地运行sbt test.如果我然后删除这个主类，sbt test 将再次失败.有没有人能解释一下这里发生了什么?
This works fine if I sbt run, and, oddly enough, also allows me to run sbt test without any problems. If I then delete this main class, sbt test once again fails. Is anybody able to shed any light on what is going on here?
感谢您的帮助！
推荐答案
实际上我运行 Scalatest from command行并成功
Actually I ran Scalatest from command line and it succeded
$ scalac -cp .:scalactic_2.13-3.2.2.jar:scalatest_2.13-3.2.2.jar:scalatest-core_2.13-3.2.2.jar:scalatest-flatspec_2.13-3.2.2.jar:scalatest-matchers-core_2.13-3.2.2.jar:scalatest-shouldmatchers_2.13-3.2.2.jar:scalatest-compatible-3.2.2.jar App.scala AppTest.scala
$ scala -cp .:scalactic_2.13-3.2.2.jar:scalatest_2.13-3.2.2.jar:scalatest-core_2.13-3.2.2.jar:scalatest-flatspec_2.13-3.2.2.jar:scalatest-matchers-core_2.13-3.2.2.jar:scalatest-shouldmatchers_2.13-3.2.2.jar:scalatest-compatible-3.2.2.jar:scala-xml_2.13-1.3.0.jar org.scalatest.run AppTest
Run starting. Expected test count is: 1
AppTest:
List
- should act as an array
Run completed in 151 milliseconds.
Total number of tests run: 1
Suites: completed 1, aborted 0
Tests: succeeded 1, failed 0, canceled 0, ignored 0, pending 0
All tests passed.
在 IntelliJ 和 sbt 中它失败了:
while in IntelliJ and sbt it failed:
(IntelliJ)
An exception or error caused a run to abort: App$ArrayDefs$IsArrSyntax$IsArrOps$$tc1d
java.lang.NoSuchFieldError: App$ArrayDefs$IsArrSyntax$IsArrOps$$tc1d
at AppTest.$anonfun$new$1(AppTest.scala:10)
at org.scalatest.OutcomeOf.outcomeOf(OutcomeOf.scala:85)
at org.scalatest.OutcomeOf.outcomeOf$(OutcomeOf.scala:83)
at org.scalatest.OutcomeOf$.outcomeOf(OutcomeOf.scala:104)
at org.scalatest.Transformer.apply(Transformer.scala:22)
at org.scalatest.Transformer.apply(Transformer.scala:20)
at org.scalatest.flatspec.AnyFlatSpecLike$$anon$5.apply(AnyFlatSpecLike.scala:1683)
at org.scalatest.TestSuite.withFixture(TestSuite.scala:196)
at org.scalatest.TestSuite.withFixture$(TestSuite.scala:195)
at org.scalatest.flatspec.AnyFlatSpec.withFixture(AnyFlatSpec.scala:1685)
at org.scalatest.flatspec.AnyFlatSpecLike.invokeWithFixture$1(AnyFlatSpecLike.scala:1681)
at org.scalatest.flatspec.AnyFlatSpecLike.$anonfun$runTest$1(AnyFlatSpecLike.scala:1693)
at org.scalatest.SuperEngine.runTestImpl(Engine.scala:306)
at org.scalatest.flatspec.AnyFlatSpecLike.runTest(AnyFlatSpecLike.scala:1693)
at org.scalatest.flatspec.AnyFlatSpecLike.runTest$(AnyFlatSpecLike.scala:1675)
at org.scalatest.flatspec.AnyFlatSpec.runTest(AnyFlatSpec.scala:1685)
at org.scalatest.flatspec.AnyFlatSpecLike.$anonfun$runTests$1(AnyFlatSpecLike.scala:1751)
at org.scalatest.SuperEngine.$anonfun$runTestsInBranch$1(Engine.scala:413)
at scala.collection.immutable.List.foreach(List.scala:333)
at org.scalatest.SuperEngine.traverseSubNodes$1(Engine.scala:401)
at org.scalatest.SuperEngine.runTestsInBranch(Engine.scala:390)
at org.scalatest.SuperEngine.$anonfun$runTestsInBranch$1(Engine.scala:427)
at scala.collection.immutable.List.foreach(List.scala:333)
at org.scalatest.SuperEngine.traverseSubNodes$1(Engine.scala:401)
at org.scalatest.SuperEngine.runTestsInBranch(Engine.scala:396)
at org.scalatest.SuperEngine.runTestsImpl(Engine.scala:475)
at org.scalatest.flatspec.AnyFlatSpecLike.runTests(AnyFlatSpecLike.scala:1751)
at org.scalatest.flatspec.AnyFlatSpecLike.runTests$(AnyFlatSpecLike.scala:1750)
at org.scalatest.flatspec.AnyFlatSpec.runTests(AnyFlatSpec.scala:1685)
at org.scalatest.Suite.run(Suite.scala:1112)
at org.scalatest.Suite.run$(Suite.scala:1094)
at org.scalatest.flatspec.AnyFlatSpec.org$scalatest$flatspec$AnyFlatSpecLike$$super$run(AnyFlatSpec.scala:1685)
at org.scalatest.flatspec.AnyFlatSpecLike.$anonfun$run$1(AnyFlatSpecLike.scala:1796)
at org.scalatest.SuperEngine.runImpl(Engine.scala:535)
at org.scalatest.flatspec.AnyFlatSpecLike.run(AnyFlatSpecLike.scala:1796)
at org.scalatest.flatspec.AnyFlatSpecLike.run$(AnyFlatSpecLike.scala:1794)
at org.scalatest.flatspec.AnyFlatSpec.run(AnyFlatSpec.scala:1685)
at org.scalatest.tools.SuiteRunner.run(SuiteRunner.scala:45)
at org.scalatest.tools.Runner$.$anonfun$doRunRunRunDaDoRunRun$13(Runner.scala:1320)
at org.scalatest.tools.Runner$.$anonfun$doRunRunRunDaDoRunRun$13$adapted(Runner.scala:1314)
at scala.collection.immutable.List.foreach(List.scala:333)
at org.scalatest.tools.Runner$.doRunRunRunDaDoRunRun(Runner.scala:1314)
at org.scalatest.tools.Runner$.$anonfun$runOptionallyWithPassFailReporter$24(Runner.scala:993)
at org.scalatest.tools.Runner$.$anonfun$runOptionallyWithPassFailReporter$24$adapted(Runner.scala:971)
at org.scalatest.tools.Runner$.withClassLoaderAndDispatchReporter(Runner.scala:1480)
at org.scalatest.tools.Runner$.runOptionallyWithPassFailReporter(Runner.scala:971)
at org.scalatest.tools.Runner$.run(Runner.scala:798)
at org.scalatest.tools.Runner.run(Runner.scala)
at org.jetbrains.plugins.scala.testingSupport.scalaTest.ScalaTestRunner.runScalaTest2or3(ScalaTestRunner.java:40)
at org.jetbrains.plugins.scala.testingSupport.scalaTest.ScalaTestRunner.main(ScalaTestRunner.java:27)
(sbt)
[error] java.lang.NoSuchFieldError: App$ArrayDefs$IsArrSyntax$IsArrOps$$tc1d
[error] at AppTest.$anonfun$new$1(AppTest.scala:10)
[error] at org.scalatest.OutcomeOf.outcomeOf(OutcomeOf.scala:85)
[error] at org.scalatest.OutcomeOf.outcomeOf$(OutcomeOf.scala:83)
[error] at org.scalatest.OutcomeOf$.outcomeOf(OutcomeOf.scala:104)
[error] at org.scalatest.Transformer.apply(Transformer.scala:22)
[error] at org.scalatest.Transformer.apply(Transformer.scala:20)
[error] at org.scalatest.flatspec.AnyFlatSpecLike$$anon$5.apply(AnyFlatSpecLike.scala:1683)
[error] at org.scalatest.TestSuite.withFixture(TestSuite.scala:196)
[error] at org.scalatest.TestSuite.withFixture$(TestSuite.scala:195)
[error] at org.scalatest.flatspec.AnyFlatSpec.withFixture(AnyFlatSpec.scala:1685)
[error] at org.scalatest.flatspec.AnyFlatSpecLike.invokeWithFixture$1(AnyFlatSpecLike.scala:1681)
[error] at org.scalatest.flatspec.AnyFlatSpecLike.$anonfun$runTest$1(AnyFlatSpecLike.scala:1693)
[error] at org.scalatest.SuperEngine.runTestImpl(Engine.scala:306)
[error] at org.scalatest.flatspec.AnyFlatSpecLike.runTest(AnyFlatSpecLike.scala:1693)
[error] at org.scalatest.flatspec.AnyFlatSpecLike.runTest$(AnyFlatSpecLike.scala:1675)
[error] at org.scalatest.flatspec.AnyFlatSpec.runTest(AnyFlatSpec.scala:1685)
[error] at org.scalatest.flatspec.AnyFlatSpecLike.$anonfun$runTests$1(AnyFlatSpecLike.scala:1751)
[error] at org.scalatest.SuperEngine.$anonfun$runTestsInBranch$1(Engine.scala:413)
[error] at scala.collection.immutable.List.foreach(List.scala:333)
[error] at org.scalatest.SuperEngine.traverseSubNodes$1(Engine.scala:401)
[error] at org.scalatest.SuperEngine.runTestsInBranch(Engine.scala:390)
[error] at org.scalatest.SuperEngine.$anonfun$runTestsInBranch$1(Engine.scala:427)
[error] at scala.collection.immutable.List.foreach(List.scala:333)
[error] at org.scalatest.SuperEngine.traverseSubNodes$1(Engine.scala:401)
[error] at org.scalatest.SuperEngine.runTestsInBranch(Engine.scala:396)
[error] at org.scalatest.SuperEngine.runTestsImpl(Engine.scala:475)
[error] at org.scalatest.flatspec.AnyFlatSpecLike.runTests(AnyFlatSpecLike.scala:1751)
[error] at org.scalatest.flatspec.AnyFlatSpecLike.runTests$(AnyFlatSpecLike.scala:1750)
[error] at org.scalatest.flatspec.AnyFlatSpec.runTests(AnyFlatSpec.scala:1685)
[error] at org.scalatest.Suite.run(Suite.scala:1112)
[error] at org.scalatest.Suite.run$(Suite.scala:1094)
[error] at org.scalatest.flatspec.AnyFlatSpec.org$scalatest$flatspec$AnyFlatSpecLike$$super$run(AnyFlatSpec.scala:1685)
[error] at org.scalatest.flatspec.AnyFlatSpecLike.$anonfun$run$1(AnyFlatSpecLike.scala:1796)
[error] at org.scalatest.SuperEngine.runImpl(Engine.scala:535)
[error] at org.scalatest.flatspec.AnyFlatSpecLike.run(AnyFlatSpecLike.scala:1796)
[error] at org.scalatest.flatspec.AnyFlatSpecLike.run$(AnyFlatSpecLike.scala:1794)
[error] at org.scalatest.flatspec.AnyFlatSpec.run(AnyFlatSpec.scala:1685)
[error] at org.scalatest.tools.Framework.org$scalatest$tools$Framework$$runSuite(Framework.scala:318)
[error] at org.scalatest.tools.Framework$ScalaTestTask.execute(Framework.scala:513)
[error] at sbt.TestRunner.runTest$1(TestFramework.scala:139)
[error] at sbt.TestRunner.run(TestFramework.scala:154)
[error] at sbt.TestFramework$$anon$3$$anonfun$$lessinit$greater$1.$anonfun$apply$1(TestFramework.scala:317)
[error] at sbt.TestFramework$.sbt$TestFramework$$withContextLoader(TestFramework.scala:277)
[error] at sbt.TestFramework$$anon$3$$anonfun$$lessinit$greater$1.apply(TestFramework.scala:317)
[error] at sbt.TestFramework$$anon$3$$anonfun$$lessinit$greater$1.apply(TestFramework.scala:317)
[error] at sbt.TestFunction.apply(TestFramework.scala:329)
[error] at sbt.Tests$.$anonfun$toTask$1(Tests.scala:311)
[error] at sbt.std.Transform$$anon$3.$anonfun$apply$2(Transform.scala:46)
[error] at sbt.std.Transform$$anon$4.work(Transform.scala:67)
[error] at sbt.Execute.$anonfun$submit$2(Execute.scala:281)
[error] at sbt.internal.util.ErrorHandling$.wideConvert(ErrorHandling.scala:19)
[error] at sbt.Execute.work(Execute.scala:290)
[error] at sbt.Execute.$anonfun$submit$1(Execute.scala:281)
[error] at sbt.ConcurrentRestrictions$$anon$4.$anonfun$submitValid$1(ConcurrentRestrictions.scala:178)
[error] at sbt.CompletionService$$anon$2.call(CompletionService.scala:37)
[error] at java.util.concurrent.FutureTask.run(FutureTask.java:266)
[error] at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
[error] at java.util.concurrent.FutureTask.run(FutureTask.java:266)
[error] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
[error] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
[error] at java.lang.Thread.run(Thread.java:748)
[error] (Test / executeTests) java.lang.NoSuchFieldError: App$ArrayDefs$IsArrSyntax$IsArrOps$$tc1d
所以问题似乎是 IntelliJ 和 sbt 如何运行 Scalatest.
So the issue seems to be how IntelliJ and sbt run Scalatest.
https://github.com/unicredit/hbase-rdd/issues/21
这篇关于使用 ScalaTest 时出现 java.lang.NoSuchFieldError的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！