SBT 程序集 - 去重

Question

我得到了以下 SBT 文件：

.
-- root
     -- plugins.sbt
-- build.sbt

plugins.sbt 包含以下内容：

addSbtPlugin("com.eed3si9n" % "sbt-assembly" % "0.12.0")

而build.sbt 包含以下内容：

import sbt.Keys._

resolvers in ThisBuild ++= Seq("Apache Development Snapshot Repository" at "https://repository.apache.org/content/repositories/snapshots/", Resolver.sonatypeRepo("public"))

name := "flink-experiment"

lazy val commonSettings = Seq(
    organization := "my.organisation",
    version := "0.1.0-SNAPSHOT"
)

val flinkVersion = "1.1.0"
val sparkVersion = "2.0.0"
val kafkaVersion = "0.8.2.1"

val hadoopDependencies = Seq(
    "org.apache.avro" % "avro" % "1.7.7" % "provided",
    "org.apache.avro" % "avro-mapred" % "1.7.7" % "provided"
)

val flinkDependencies = Seq(
    "org.apache.flink" %% "flink-scala" % flinkVersion % "provided",
    "org.apache.flink" %% "flink-streaming-scala" % flinkVersion % "provided",
    "org.apache.flink" %% "flink-connector-kafka-0.8" % flinkVersion exclude("org.apache.kafka", "kafka_${scala.binary.version}")
)

val sparkDependencies = Seq(
    "org.apache.spark" %% "spark-core" % sparkVersion % "provided",
    "org.apache.spark" %% "spark-streaming" % sparkVersion % "provided",
    "org.apache.spark" %% "spark-streaming-kafka-0-8" % sparkVersion exclude("org.apache.kafka", "kafka_${scala.binary.version}")
)

val kafkaDependencies = Seq(
    "org.apache.kafka" %% "kafka" % "0.8.2.1"
)

val toolDependencies = Seq(
    "com.github.scopt" %% "scopt" % "3.5.0"
)

val testDependencies = Seq(
    "org.scalactic" %% "scalactic" % "2.2.6",
    "org.scalatest" %% "scalatest" % "2.2.6" % "test"
)

lazy val root = (project in file(".")).
    settings(commonSettings: _*).
    settings(
        libraryDependencies ++= hadoopDependencies,
        libraryDependencies ++= flinkDependencies,
        libraryDependencies ++= sparkDependencies,
        libraryDependencies ++= kafkaDependencies,
        libraryDependencies ++= toolDependencies,
        libraryDependencies ++= testDependencies
    ).
    enablePlugins(AssemblyPlugin)

run in Compile <<= Defaults.runTask(fullClasspath in Compile, mainClass in(Compile, run), runner in(Compile, run))

mainClass in assembly := Some("my.organization.experiment.Experiment")
assemblyOption in assembly := (assemblyOption in assembly).value.copy(includeScala = false)

现在sbt clean assembly 遗憾地给出了以下例外：

[error] (root/*:assembly) deduplicate: different file contents found in the following:
[error] /home/kevin/.ivy2/cache/org.apache.spark/spark-streaming-kafka-0-8_2.10/jars/spark-streaming-kafka-0-8_2.10-2.0.0.jar:org/apache/spark/unused/UnusedStubClass.class
[error] /home/kevin/.ivy2/cache/org.apache.spark/spark-tags_2.10/jars/spark-tags_2.10-2.0.0.jar:org/apache/spark/unused/UnusedStubClass.class
[error] /home/kevin/.ivy2/cache/org.spark-project.spark/unused/jars/unused-1.0.0.jar:org/apache/spark/unused/UnusedStubClass.class

我该如何解决这个问题？

Answer 1

https://github.com/sbt/sbt-assembly#excluding-jars-and-files

您可以定义 assemblyMergeStrategy 并可能丢弃您列出的所有文件，因为它们都在“未使用”包中。

Answer 2

您可以覆盖默认的冲突策略：

    val defaultMergeStrategy: String => MergeStrategy = { 
    case x if Assembly.isConfigFile(x) =>
      MergeStrategy.concat
    case PathList(ps @ _*) if Assembly.isReadme(ps.last) || Assembly.isLicenseFile(ps.last) =>
      MergeStrategy.rename
    case PathList("META-INF", xs @ _*) =>
      (xs map {_.toLowerCase}) match {
        case ("manifest.mf" :: Nil) | ("index.list" :: Nil) | ("dependencies" :: Nil) =>
          MergeStrategy.discard
        case ps @ (x :: xs) if ps.last.endsWith(".sf") || ps.last.endsWith(".dsa") =>
          MergeStrategy.discard
        case "plexus" :: xs =>
          MergeStrategy.discard
        case "services" :: xs =>
          MergeStrategy.filterDistinctLines
        case ("spring.schemas" :: Nil) | ("spring.handlers" :: Nil) =>
          MergeStrategy.filterDistinctLines
        case _ => MergeStrategy.deduplicate
      }
    case _ => MergeStrategy.deduplicate
  }

你可以看到程序集默认策略是MergeStrategy.deduplicate，你可以添加一个新的案例case UnusedStubClass => MergeStrategy.first