Question

我们无法运行主类。我们使用sbt 13.2对抗scala 2.9.3

以下是build.sbt中的条目：

mainClass in (Compile,run) := Some("com.mycompany.swlab.sparkpoc.sql.DbPing")

让我们做一个“sbt run”：

C:\apps\simplews>sbt run
"sbt13"
Picked up _JAVA_OPTIONS: -Djava.net.preferIPv4Stack=true
[info] Loading project definition from C:\apps\simplews\project
[info] Set current project to websocket-simple (in build file:/C:/apps/simplews/)
java.lang.RuntimeException: No main class detected.
        at scala.sys.package$.error(package.scala:27)

这是源文件。注意它是一个带main（）方法的对象。所以我们应该能够执行它。

package com.mycompany.swlab.sparkpoc.sql

import org.apache.log4j.Logger

object DbPing {
  import java.sql.{DriverManager, Connection}


  def main(args: Array[String]) {

我还试图提供如下运行的特定类：

> run com.mycompany.swlab.sparkpoc.sql.DB org.apache.hadoop.hive.jdbc.HiveDriver jdbc:hive://localhost:10000/default "" ""

这是完整输出

Picked up _JAVA_OPTIONS: -Djava.net.preferIPv4Stack=true
[info] Loading project definition from C:\apps\simplews\project
[info] Set current project to websocket-simple (in build file:/C:/apps/simplews/)
> run com.mycompany.swlab.sparkpoc.sql.DB org.apache.hadoop.hive.jdbc.HiveDriver jdbc:hive://localhost:10000/default "" ""
java.lang.RuntimeException: No main class detected.
        at scala.sys.package$.error(package.scala:27)
[trace] Stack trace suppressed: run last root/*:run for the full output.
[error] (root/*:run) No main class detected.
[error] Total time: 0 s, completed May 27, 2014 9:13:55 PM

Answer 1

问题在于项目/ Build.scala已损坏。我恢复了一个简单的build.sbt，解决了这个问题。

sbt run没有从build.sbt中获取mainClass

1 个答案: