我有一个Maven-Scala项目。当我想在IntelliJ中构建它时，它会进行编译等。可以工作，但是输出 jar为空，除了pom.xml。
当使用mvn scala:compile通过命令行构建整个项目时，出现以下错误：
[INFO] Compiling 67 source files to /Users/my.name/Documents/company/util/util/target/classes at 1555483575272
[ERROR] error: scala.reflect.internal.MissingRequirementError: object java.lang.Object in compiler mirror not found.
[ERROR] at scala.reflect.internal.MissingRequirementError$.signal(MissingRequirementError.scala:17)
[ERROR] at scala.reflect.internal.MissingRequirementError$.notFound(MissingRequirementError.scala:18)
[ERROR] at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:53)
[ERROR] at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:45)
[ERROR] at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:45)
[ERROR] at scala.reflect.internal.Mirrors$RootsBase.getModuleOrClass(Mirrors.scala:66)
[ERROR] at scala.reflect.internal.Mirrors$RootsBase.getClassByName(Mirrors.scala:102)
[ERROR] at scala.reflect.internal.Mirrors$RootsBase.getRequiredClass(Mirrors.scala:105)
[ERROR] at scala.reflect.internal.Definitions$DefinitionsClass.ObjectClass$lzycompute(Definitions.scala:257)
[ERROR] at scala.reflect.internal.Definitions$DefinitionsClass.ObjectClass(Definitions.scala:257)
[ERROR] at scala.reflect.internal.Definitions$DefinitionsClass.init(Definitions.scala:1394)
[ERROR] at scala.tools.nsc.Global$Run.<init>(Global.scala:1215)
[ERROR] at scala.tools.nsc.Driver.doCompile(Driver.scala:31)
[ERROR] at scala.tools.nsc.MainClass.doCompile(Main.scala:23)
[ERROR] at scala.tools.nsc.Driver.process(Driver.scala:51)
[ERROR] at scala.tools.nsc.Driver.main(Driver.scala:64)
[ERROR] at scala.tools.nsc.Main.main(Main.scala)
[ERROR] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[ERROR] at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
[ERROR] at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
[ERROR] at java.base/java.lang.reflect.Method.invoke(Method.java:564)
[ERROR] at scala_maven_executions.MainHelper.runMain(MainHelper.java:164)
[ERROR] at scala_maven_executions.MainWithArgsInFile.main(MainWithArgsInFile.java:26)
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 8.256 s
[INFO] Finished at: 2019-04-17T08:46:16+02:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal net.alchim31.maven:scala-maven-plugin:3.3.1:compile (default-cli) on project util: wrap: org.apache.commons.exec.ExecuteException: Process exited with an error: 1 (Exit value: 1)
我也可以运行mvn compile，但是成功，但是会产生一个空的jar：
[INFO] Building util 0.0.1-SNAPSHOT
[INFO] --------------------------------[ jar ]---------------------------------
[INFO]
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ util ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory /Users/markus.geilehner/Documents/Syniverse/util/util/src/main/resources
[INFO]
[INFO] --- maven-compiler-plugin:3.7.0:compile (default-compile) @ util ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 6 source files to /Users/markus.geilehner/Documents/Syniverse/util/util/target/classes
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 2.334 s
[INFO] Finished at: 2019-04-17T09:03:55+02:00
[INFO] ------------------------------------------------------------------------
-util
--src
---main
----scala
-----com.company.util
------Scala Classes and packages
这是pom.xml的某些部分。我使用了 net.alchim Scala-maven插件。 构建过程配置为使用scala目录。
<build>
<sourceDirectory>src/main/scala</sourceDirectory>
<testSourceDirectory>src/test/scala</testSourceDirectory>
<plugins>
<plugin>
<groupId>net.alchim31.maven</groupId>
<artifactId>scala-maven-plugin</artifactId>
<version>3.3.1</version>
</plugin>
<plugin>
<artifactId>maven-jar-plugin</artifactId>
<version>2.4</version>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-site-plugin</artifactId>
<version>3.0</version>
<configuration>
<reportPlugins>
<plugin>
<artifactId>maven-project-info-reports-plugin</artifactId>
<version>2.2</version>
</plugin>
<plugin>
<groupId>net.alchim31.maven</groupId>
<artifactId>scala-maven-plugin</artifactId>
<version>3.3.1</version>
<configuration>
<jvmArgs>
<jvmArg>-Xms64m</jvmArg>
<jvmArg>-Xmx1024m</jvmArg>
</jvmArgs>
</configuration>
</plugin>
</reportPlugins>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>${maven-compiler-plugin.version}</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
</plugins>
答案 0 :(得分：3)
在将scala项目与maven结合使用时，我遇到了相同的错误。
一个问题可能是您使用了错误的Java版本（9/10）尝试将其更改为IntelliJ中的Java 8（1.8）（文件=>项目结构）。
在您的pom中，在maven-scala插件下方添加以下执行。
<executions>
<execution>
<id>compile</id>
<goals>
<goal>compile</goal>
</goals>
<phase>compile</phase>
</execution>
<execution>
<id>test-compile</id>
<goals>
<goal>testCompile</goal>
</goals>
<phase>test-compile</phase>
</execution>
<execution>
<phase>process-resources</phase>
<goals>
<goal>compile</goal>
</goals>
</execution>
</executions>
全新安装，然后重试。