Scala IntelliJ 库导入错误答案

【问题标题】：Scala IntelliJ library import errorsScala IntelliJ 库导入错误
【发布时间】：2020-10-18 20:28:33
【问题描述】：

我是 scala 的新手，我正在尝试在我的 build.sbt 中导入以下库。当 IntelliJ 进行自动更新时，我收到以下错误：

Error while importing sbt project:

List([info] welcome to sbt 1.3.13 (Oracle Corporation Java 1.8.0_251)
[info] loading global plugins from C:\Users\diego\.sbt\1.0\plugins
[info] loading project definition from C:\Users\diego\development\Meetup\Stream-Processing\project
[info] loading settings for project stream-processing from build.sbt ...
[info] set current project to Stream-Processing (in build file:/C:/Users/diego/development/Meetup/Stream-Processing/)
[info] sbt server started at local:sbt-server-80d70f9339b81b4d026a
sbt:Stream-Processing>
[info] Defining Global / sbtStructureOptions, Global / sbtStructureOutputFile and 1 others.
[info] The new values will be used by cleanKeepGlobs
[info]  Run `last` for details.
[info] Reapplying settings...
[info] set current project to Stream-Processing (in build file:/C:/Users/diego/development/Meetup/Stream-Processing/)
[info] Applying State transformations org.jetbrains.sbt.CreateTasks from C:/Users/diego/.IntelliJIdea2019.3/config/plugins/Scala/repo/org.jetbrains/sbt-structure-extractor/scala_2.12/sbt_1.0/2018.2.1+4-88400d3f/jars/sbt-structure-extractor.jar
[info] Reapplying settings...
[info] set current project to Stream-Processing (in build file:/C:/Users/diego/development/Meetup/Stream-Processing/)
[warn]
[warn]  Note: Unresolved dependencies path:
[error] stack trace is suppressed; run 'last update' for the full output
[error] stack trace is suppressed; run 'last ssExtractDependencies' for the full output
[error] (update) sbt.librarymanagement.ResolveException: Error downloading org.apache.kafka:kafka-clients_2.11:2.3.1
[error]   Not found
[error]   Not found
[error]   not found: C:\Users\diego\.ivy2\local\org.apache.kafka\kafka-clients_2.11\2.3.1\ivys\ivy.xml
[error]   not found: https://repo1.maven.org/maven2/org/apache/kafka/kafka-clients_2.11/2.3.1/kafka-clients_2.11-2.3.1.pom
[error] (ssExtractDependencies) sbt.librarymanagement.ResolveException: Error downloading org.apache.kafka:kafka-clients_2.11:2.3.1
[error]   Not found
[error]   Not found
[error]   not found: C:\Users\diego\.ivy2\local\org.apache.kafka\kafka-clients_2.11\2.3.1\ivys\ivy.xml
[error]   not found: https://repo1.maven.org/maven2/org/apache/kafka/kafka-clients_2.11/2.3.1/kafka-clients_2.11-2.3.1.pom
[error] Total time: 2 s, completed Jun 28, 2020 12:11:24 PM
[info] shutting down sbt server)

这是我的 build.sbt 文件：

name := "Stream-Processing"

version := "1.0"

scalaVersion := "2.11.8"

libraryDependencies += "org.apache.spark" %% "spark-sql" % "2.4.4"

// https://mvnrepository.com/artifact/org.apache.spark/spark-sql-kafka-0-10_2.12
libraryDependencies += "org.apache.spark" %% "spark-sql-kafka-0-10" % "2.4.4"

// https://mvnrepository.com/artifact/org.apache.kafka/kafka-clients
libraryDependencies += "org.apache.kafka" %% "kafka-clients" % "2.3.1"

// https://mvnrepository.com/artifact/mysql/mysql-connector-java
libraryDependencies += "mysql" % "mysql-connector-java" % "8.0.18"

// https://mvnrepository.com/artifact/org.mongodb.spark/mongo-spark-connector
libraryDependencies += "org.mongodb.spark" %% "mongo-spark-connector" % "2.4.1"

我创建了一个 Scala 项目只是为了确保 Spark 可以正常工作，并且我使用 Kafka 的 python 项目也可以正常工作，所以我确信这不是 spark/kafka 问题。我收到该错误的任何原因？

【问题讨论】：

Kafka 客户端是一个 Java 库，而不是 Scala 库。因此，您只需要使用一个% 而不是两个%%：libraryDependencies += "org.apache.kafka" % "kafka-clients" % "2.3.1" 您那里的链接对此非常明确。

标签： scala apache-spark intellij-idea apache-kafka sbt

【解决方案1】：

尝试在"kafka-clients" 之前删除一个%：

libraryDependencies += "org.apache.kafka" % "kafka-clients" % "2.3.1"

SBT 中%% 的语义是它会将使用的Scala 版本附加到工件名称中，因此它变成org.apache.kafka:kafka-clients_2.11:2.3.1，如错误消息所示。注意_2.11 后缀。
这是 Scala 库的一个很好的简写，但与 Java 库一起使用时可能会让初学者感到困惑。

【讨论】：