带有 Spark 解释器的 Zeppelin 忽略在类/函数定义之外声明的导入 [英] Zeppelin with Spark interpreter ignores imports declared outside of class/function definition

问题描述

我正在尝试在 Zeppelin 0.8.0 中使用一些带有 Spark 解释器的 Scala 代码:

I'm trying to use some Scala code in Zeppelin 0.8.0 with Spark interpreter:

%spark
import scala.beans.BeanProperty

class Node(@BeanProperty val parent: Option[Node]) {
}

但是进口好像没有考虑

import scala.beans.BeanProperty
<console>:14: error: not found: type BeanProperty
                  @BeanProperty val parent: Option[Node]) {
                   ^

我发现以下代码有效:

class Node(@scala.beans.BeanProperty val parent: Option[Node]) {
}

这也很好用:

def loadCsv(CSVPATH: String): DataFrame = {
    import org.apache.spark.sql.types._
    //[...] some code
    val schema = StructType(
        firstRow.map(s => StructField(s, StringType))
    )
    //[…] some code again
}

所以我想如果它在大括号之间导入或在使用时直接用 path.to.package.Class 指定，一切都可以正常工作.

So I guess everything works fine if it is imported between braces or directly specified with a path.to.package.Class when used.

问题:如何在类/函数定义之外导入?

QUESTION: How do I import outside of a class/function definition?

推荐答案

通过 path.to.package.Class 导入在 Zeppelin 中运行良好.您可以尝试导入和使用 java.sql.Date;

Importing by path.to.package.Class works well in Zeppelin. You can try it with importing and using java.sql.Date;

import java.sql.Date
val date = Date.valueOf("2019-01-01")

问题在于 Zeppelin 上下文.如果您尝试在 Zeppelin 中使用以下代码片段，您会发现它运行良好；

The problem is about Zeppelin context. If you try to use following code snippets in Zeppelin, you will see that it works fine;

object TestImport {
     import scala.beans.BeanProperty
     class Node(@BeanProperty val parent: Option[Node]){}
}
val testObj = new TestImport.Node(None)
testObj.getParent
//prints Option[Node] = None

希望能帮到你！

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