Kotlin和MockK抛出com.sun.tools.attach.AttachNotSupportedException异常：没有可用的提供程序。

Question

使用Zulu JDK（8u242b20）在Java应用程序中，当尝试从Kotlin类运行测试时，我收到以下异常：

class SomeTest {
  @MockK
  private lateinit var fileService: FileService

  @SetUp
  fun setUp(){
    MockKAnnotations.init(this, relaxed = true)
  }

  @Test
  fun `foo`(){
    // do something
  }
}

异常如下所示。

java.lang.ExceptionInInitializerError
    at com.something.SomeTest.setUp(SomeTest.kt:121)
    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.RunBefores.evaluate(RunBefores.java:24)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
    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$2.evaluate(ParentRunner.java:268)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
    at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
Caused by: java.lang.IllegalStateException: Error during attachment using: net.bytebuddy.agent.ByteBuddyAgent$AttachmentProvider$Compound@6156496
    at net.bytebuddy.agent.ByteBuddyAgent.install(ByteBuddyAgent.java:384)
    at net.bytebuddy.agent.ByteBuddyAgent.install(ByteBuddyAgent.java:358)
    at net.bytebuddy.agent.ByteBuddyAgent.install(ByteBuddyAgent.java:326)
    at net.bytebuddy.agent.ByteBuddyAgent.install(ByteBuddyAgent.java:312)
    at io.mockk.proxy.jvm.JvmMockKAgentFactory.initInstrumentation(JvmMockKAgentFactory.kt:127)
    at io.mockk.proxy.jvm.JvmMockKAgentFactory.init(JvmMockKAgentFactory.kt:34)
    at io.mockk.impl.JvmMockKGateway.<init>(JvmMockKGateway.kt:46)
    at io.mockk.impl.JvmMockKGateway.<clinit>(JvmMockKGateway.kt:169)
    ... 23 more
Caused by: java.lang.reflect.InvocationTargetException
    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 net.bytebuddy.agent.Attacher.install(Attacher.java:84)
    at net.bytebuddy.agent.ByteBuddyAgent.install(ByteBuddyAgent.java:379)
    ... 30 more
Caused by: com.sun.tools.attach.AttachNotSupportedException: no providers installed
    at com.sun.tools.attach.VirtualMachine.attach(VirtualMachine.java:208)
    ... 36 more


java.lang.NoClassDefFoundError: Could not initialize class io.mockk.impl.JvmMockKGateway

    at com.something.SomeTest.setUp(SomeTest.kt:121)
    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.RunBefores.evaluate(RunBefores.java:24)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
    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$2.evaluate(ParentRunner.java:268)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
    at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)

使用MockK之后，使用kotlin之前是可以的。您有任何想法是什么原因？

我不知道还需要添加哪些细节，一切都应该从代码中可见，但由于stackoverflow的限制，我仍然无法发布问题，所以这只是生成一些随机的废话文本。

- Michael Bláha

Answer 1

ByteBuddy需要位于JDK的tools.jar库中的类，而这个库很可能缺失于你的类路径中。你可以将$JAVA_HOME/lib添加到你的类路径中，或者使用maven添加依赖。

    <dependency>
        <groupId>com.sun</groupId>
        <artifactId>tools</artifactId>
        <version>${java.version}</version>
        <scope>system</scope>
        <systemPath>${java.home}/../lib/tools.jar</systemPath>
    </dependency>

- Jakub Hesoun