使用 AspectJ 和 Scala 时出错

如何解决使用 AspectJ 和 Scala 时出错

我正在尝试将 IntelliJ 上的 Scala 和 AspectJ 作为 IDE。 #文件结构

Sample.scala - (包含main方法的类)

package sample

class SampleClass {
  def printSample():Unit = println("hello")
}

object SampleObject extends App {
  val sample = new SampleClass
  sample.printSample()
}

Tracer.scala -（Tracer 函数或换句话说方面）

package sample

import org.aspectj.lang.annotation._

@Aspect
class Tracer {

  @Before("execution(* sample.SampleClass.printSample(..))")
  def printSample() {
    println("Printing sample:")
  }
}

build.sbt - 为了运行 sbt 命令（sbt compile 和 sbt run）

name := "testingAspectScalaFullexample"

version := "0.1"

scalaVersion := "2.13.5"
lazy val buildSettings = Seq(
  organization := "com.lightbend.sbt.aspectj",version := "0.1-SNAPSHOT",scalaVersion := "2.12.1"
)


lazy val sample = (project in file("."))
  .settings(buildSettings)
  .aggregate(tracer,instrumented)

// precompiled aspects
lazy val tracer = (project in file("tracer"))
  .enablePlugins(SbtAspectj)
  .settings(buildSettings)
  .settings(
    // input compiled scala classes
    aspectjinputs in Aspectj += (aspectjCompiledClasses in Aspectj).value,// ignore warnings
    aspectjLintProperties in Aspectj += "invalidAbsoluteTypeName = ignore",aspectjLintProperties in Aspectj += "adviceDidNotMatch = ignore",// replace regular products with compiled aspects
    products in Compile := (products in Aspectj).value
  )

// test that the instrumentation works
lazy val instrumented = (project in file("instrumented"))
  .enablePlugins(SbtAspectj)
  .settings(buildSettings)
  .settings(
    // add the compiled aspects from tracer
    aspectjBinaries in Aspectj ++= (products in Compile in tracer).value,// weave this project's classes
    aspectjinputs in Aspectj += (aspectjCompiledClasses in Aspectj).value,products in Compile := (products in Aspectj).value,products in Runtime := (products in Compile).value
  ).dependsOn(tracer)

// for sbt scripted test:
TaskKey[Unit]("check") := {
  import scala.sys.process.Process

  val cp = (fullClasspath in Compile in instrumented).value
  val mc = (mainClass in Compile in instrumented).value
  val opts = (javaoptions in run in Compile in instrumented).value

  val expected = "Printing sample:\nhello\n"
  val output = Process("java",opts ++ Seq("-classpath",cp.files.absstring,mc getorElse "")).!!
  if (output != expected) {
    println("Unexpected output:")
    println(output)
    println("Expected:")
    println(expected)
    sys.error("Unexpected output")
  } else {
    print(output)
  }
}

然而，当我运行 sbt compile 时，这个错误突然出现：

Weaving 1 input to,<path>\SpringIn28Minutes-master\SpringIn28Minutes-master\testingAspectScalaFullexample\tracer\target\scala-2.12\aspectj\classes...
[error] error can't determine superclass of missing type java.lang.Object
[error] when batch building BuildConfig[null] #Files=0 AopXmls=#0
[error]  [Xlint:cantFindType]
[error] org.aspectj.bridge.AbortException: AspectJ Failed
[error]         at com.lightbend.sbt.SbtAspectj$Ajc$.runAjcMain(SbtAspectj.scala:212)
[error]         at com.lightbend.sbt.SbtAspectj$Ajc$.runAjc(SbtAspectj.scala:124)
[error]         at com.lightbend.sbt.SbtAspectj$Ajc$.$anonfun$ajcTask$2(SbtAspectj.scala:111)
[error]         at sbt.util.FileFunction$.$anonfun$cached$1(FileFunction.scala:80)
[error]         at sbt.util.FileFunction$.$anonfun$cached$4(FileFunction.scala:153)
[error]         at sbt.util.Difference.apply(Tracked.scala:414)
[error]         at sbt.util.Difference.apply(Tracked.scala:394)
[error]         at sbt.util.FileFunction$.$anonfun$cached$3(FileFunction.scala:149)
[error]         at sbt.util.Difference.apply(Tracked.scala:414)
[error]         at sbt.util.Difference.apply(Tracked.scala:389)
[error]         at sbt.util.FileFunction$.$anonfun$cached$2(FileFunction.scala:148)
[error]         at com.lightbend.sbt.SbtAspectj$Ajc$.$anonfun$ajcTask$1(SbtAspectj.scala:116)
[error]         at scala.Function1.$anonfun$compose$1(Function1.scala:49)
[error]         at sbt.internal.util.$tilde$greater.$anonfun$$u2219$1(TypeFunctions.scala:62)
[error]         at sbt.std.Transform$$anon$4.work(Transform.scala:68)
[error]         at sbt.Execute.$anonfun$submit$2(Execute.scala:282)
[error]         at sbt.internal.util.ErrorHandling$.wideConvert(ErrorHandling.scala:23)
[error]         at sbt.Execute.work(Execute.scala:291)
[error]         at sbt.Execute.$anonfun$submit$1(Execute.scala:282)
[error]         at sbt.ConcurrentRestrictions$$anon$4.$anonfun$submitValid$1(ConcurrentRestrictions.scala:265)
[error]         at sbt.CompletionService$$anon$2.call(CompletionService.scala:64)
[error]         at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
[error]         at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executo
rs.java:515)
[error]         at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
[error]         at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoo
lExecutor.java:1130)
[error]         at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPo
olExecutor.java:630)
[error]         at java.base/java.lang.Thread.run(Thread.java:831)
[error] (tracer / Aspectj / ajc) org.aspectj.bridge.AbortException: AspectJ Failed

解决方法

好的，您正在使用插件源代码存储库中的 this example。你为什么不直接说出来并链接到它？您使它看起来好像是您自己创建的示例。我找到了它，还有 project/plugins.sbt 你没有在此处发布未。就像我之前在聊天中告诉你的那样，我是一个 Scala 菜鸟，我一生从未使用过它，也不知道文件丢失了。那花了我很多时间。为什么你在这里发布一个不完整的示例项目，而不是像我要求你那样在 GitHub 上发布它？然后我可以克隆该项目并运行它。直到我在网上找到示例代码，我才意识到你的代码不完整。

另外，我的IDE IntelliJ IDEA 无法导入示例项目，一定是当前版本存在某种bug。我只能从 sbt shell 编译和运行。在那里，我终于可以重现您的问题了。

其实解释很简单：插件已经过时了，应该尽快更新。它依赖于仅支持 Java 8 的 AspectJ 编译器工具 1.8.10。它甚至不是最新的 1.8 版本，应该是 1.8.13。此外，该插件将 AspectJ Runtime 1.8.10 作为运行时依赖项导出到使用该插件的项目。另见：

• https://github.com/sbt/sbt-aspectj/blob/8ff3a1ad4224934dabe222205eb89c985670f240/build.sbt#L7
• https://github.com/sbt/sbt-aspectj/blob/8ff3a1ad4224934dabe222205eb89c985670f240/src/main/scala/com/lightbend/sbt/SbtAspectj.scala#L30

只要你在 JDK 1.8 上编译和运行你的项目，一切都很好。如果您使用更新的 JDK，解决方案是覆盖依赖项。将其放入 project/plugins.sbt：

addSbtPlugin("org.jetbrains" % "sbt-ide-settings" % "1.1.0")
addSbtPlugin("com.lightbend.sbt" % "sbt-aspectj" % "0.11.0")
dependencyOverrides += "org.aspectj" % "aspectjrt" % "1.9.6"
dependencyOverrides += "org.aspectj" % "aspectjtools" % "1.9.6"

AspectJ 1.9.6 最高支持语言级别 14。即将发布支持 Java 15+16 的 1.9.7 版本。但是如果你在 JDK 16 上运行，但编译到不高于目标 14，你应该没问题。

---

顺便说一句，测试是特定于平台的，在 Windows 上会失败，因为它需要 UNIX 行分隔符 (LF)，而 Windows 使用 CR+LF：

val expected = "Printing sample:\nhello\n"

您应该将其更改为：

val LF = System.lineSeparator()
val expected = "Printing sample:" + LF + "hello" + LF