使用scopt OptionParser和Spark时的NoClassDefFoundError

Question

我使用Apache Spark版本1.2.1和Scala版本2.10.4.我想让示例MovieLensALS正常工作.但是,我遇到了scopt库的错误,这是代码中的一个要求.任何帮助,将不胜感激.我的build.sbt如下:

name := "Movie Recommender System"

version := "1.0"

scalaVersion := "2.10.4"

libraryDependencies += "org.apache.spark" %% "spark-core" % "1.2.1"

libraryDependencies += "org.apache.spark" %% "spark-graphx" % "1.2.1"

libraryDependencies += "org.apache.spark"  % "spark-mllib_2.10" % "1.2.1"

libraryDependencies += "com.github.scopt" %% "scopt" % "3.2.0"

resolvers += Resolver.sonatypeRepo("public")

我得到的错误如下:

   Exception in thread "main" java.lang.NoClassDefFoundError: scopt/OptionParser
    at MovieLensALS.main(MovieLensALS.scala)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.apache.spark.deploy.SparkSubmit$.launch(SparkSubmit.scala:358)
    at org.apache.spark.deploy.SparkSubmit$.main(SparkSubmit.scala:75)
    at org.apache.spark.deploy.SparkSubmit.main(SparkSubmit.scala)

    Caused by: java.lang.ClassNotFoundException: scopt.OptionParser
    at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
    ... 8 more
    Using Spark's default log4j profile: org/apache/spark/log4j-defaults.properties

在运行sbt程序集来构建jar时,我收到以下错误:

[error] Not a valid command: assembly
[error] Not a valid project ID: assembly
[error] Expected ':' (if selecting a configuration)
[error] Not a valid key: assembly
[error] assembly
[error]         ^

编辑:根据Justin Piphony的建议,sbt的GitHub页面中列出的解决方案帮助解决了这个错误.基本上在项目/目录中创建文件assembly.sbt并添加该行 addSbtPlugin("com.eed3si9n" % "sbt-assembly" % "0.13.0")

请注意,应根据使用的版本添加版本.

Answer 1

您需要将其打包scopt到 jar 中。sbt 默认情况下不这样做。要创建这个 fat jar，您需要使用sbt-assemble