带有Spark解释器的Zeppelin会忽略在类/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

我正在尝试使用Spark解释器在Zeppelin 0.8.0中使用一些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]) {
}

但是似乎没有考虑进口

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

编辑:我发现以下代码有效:

I found out that the following code works :

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

这也很好:

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
}

因此，我想如果将其导入到括号之间或在使用时直接用path.to.package.Class指定，则一切正常.

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

在Zeppelin中，通过path.to.package.Class导入非常有效.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")

问题与 Zeppelin上下文有关.如果您尝试在Zeppelin中使用以下代码段，则会发现它工作正常；

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

希望对您有帮助！

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