将df.show()的内容另存为Spark-scala应用程序中的字符串 [英] Saving contents of df.show() as a string in spark-scala app

问题描述

我需要将df.show()的输出保存为字符串，以便我可以直接通过电子邮件发送.

I need to save the output of df.show() as a string so that i can email it directly.

例如，以下示例摘自官方spark文档，

For ex., the below example taken from official spark docs,:

val df = spark.read.json("examples/src/main/resources/people.json")

// Displays the content of the DataFrame to stdout
df.show()
// +----+-------+
// | age|   name|
// +----+-------+
// |null|Michael|
// |  30|   Andy|
// |  19| Justin|
// +----+-------+

我需要将上表另存为在控制台中打印的字符串.我确实看过log4j来打印日志，但是只记录输出结果却找不到任何信息.

I need to save the above table as a string which is printed in the console. I did look at log4j to print the log, but couldnt come across any info on logging only the output.

有人可以帮我吗?

推荐答案

scala.Console对于此类问题具有withOut方法:

scala.Console has a withOut method for this kind of thing:

val outCapture = new ByteArrayOutputStream
Console.withOut(outCapture) {
  df.show()
}
val result = new String(outCapture.toByteArray)

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