Kotlin：单元测试期间的@JvmStatic方法NoClassDefFoundError/ClassNotFoundException [重复]

Question

这是我试图从我的单元测试中调用的类

package bj.discogsbrowser.artistreleases

class ArtistResultFactory {
    companion object {
        @JvmStatic fun buildArtistResult(members: Int): ArtistResult {
            val artistResult = ArtistResult()
            artistResult.nameVariations = listOf("ye")
            artistResult.dataQuality = "really good quality, we have the best qualities"
            return artistResult
        }
    }
}

这是测试的样子：

@Test
fun setArtistNoMembers_displaysNoMembers() {
    controller.setArtist(ArtistResultFactory.buildArtistResult(0))
    ...
    assertEquals(copyOfModels.size, 8)
}

Java 中的相同测试（也失败了）：

@Test
public void setArtistNoMembers_displaysNoMembers()
{
    controller.setArtist(ArtistResultFactory.buildArtistResult(0));
    ...
    assertEquals(copyOfModels.size(), 8);
}

在 Kotlin 和 Java 中，我都得到了堆栈跟踪：

java.lang.NoClassDefFoundError: bj/discogsbrowser/artistreleases/ArtistResultFactory

    at bj.discogsbrowser.artist.ArtistControllerTest.setArtistNoMembers_displaysNoMembers(ArtistControllerTest.java:70)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.robolectric.RobolectricTestRunner$HelperTestRunner$1.evaluate(RobolectricTestRunner.java:488)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
    at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
    at org.robolectric.internal.SandboxTestRunner$2.evaluate(SandboxTestRunner.java:209)
    at org.robolectric.internal.SandboxTestRunner.runChild(SandboxTestRunner.java:109)
    at org.robolectric.internal.SandboxTestRunner.runChild(SandboxTestRunner.java:36)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.robolectric.internal.SandboxTestRunner$1.evaluate(SandboxTestRunner.java:63)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
    at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:51)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at com.intellij.rt.execution.application.AppMainV2.main(AppMainV2.java:131)
Caused by: java.lang.ClassNotFoundException: bj.discogsbrowser.artistreleases.ArtistResultFactory
    at org.robolectric.internal.bytecode.SandboxClassLoader.getByteCode(SandboxClassLoader.java:161)
    at org.robolectric.internal.bytecode.SandboxClassLoader.maybeInstrumentClass(SandboxClassLoader.java:108)
    at org.robolectric.internal.bytecode.SandboxClassLoader.findClass(SandboxClassLoader.java:101)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 32 more

我觉得这可能与我的sourceSets 有关，因为当我删除这些行时，代码将无法编译。

sourceSets {
        test {
            java.srcDirs += "$projectDir/src/testShared"
        }

        androidTest {
            java.srcDirs += "$projectDir/src/testShared"
        }
    }

ArtistResultFactory 位于/src/testShared/。当它是一个 Java 类时，测试运行良好。

我的应用 build.gradle 包括

apply plugin: "kotlin-android"
apply plugin: 'kotlin-android-extensions'

在顶部。

Answer 1

您需要将其设为“对象”而不是“类”，以便在 Kotlin 中访问它的单例样式。

如果你确实把它变成了一个对象（这对于像工厂这样通常是单例的东西来说是正确的做法），那么我相信在 Java 中你必须先做一个 .getINSTANCE() 才能访问该方法（不确定是否可以将其设为静态）因为我不相信 Kotlin 中的对象允许伴随对象（不过我可能会误会）。