如何在Spark上将JSON字符串转换为数据帧 [英] how to convert json string to dataframe on spark

问题描述

我想在Spark上将下面的字符串变量转换为dataframe.

I want to convert string variable below to dataframe on spark.

val jsonStr = "{ "metadata": { "key": 84896, "value": 54 }}"

我知道如何从json文件创建数据框.

I know how to create dataframe from json file.

sqlContext.read.json("file.json")

但是我不知道如何从字符串变量创建数据框.

but I don't know how to create dataframe from string variable.

如何将json字符串变量转换为数据帧.

How can I convert json String variable to dataframe.

推荐答案

对于

对于 Spark 2.1.x :

val events = sc.parallelize("""{"action":"create","timestamp":"2016-01-07T00:01:17Z"}""" :: Nil)    
val df = sqlContext.read.json(events)

提示:这正在使用sqlContext.read.json(jsonRDD: RDD[Stirng])重载. 还有sqlContext.read.json(path: String)，它可以直接读取Json文件.

Hint: this is using sqlContext.read.json(jsonRDD: RDD[Stirng]) overload. There is also sqlContext.read.json(path: String) where it reads a Json file directly.

对于旧版本:

val jsonStr = """{ "metadata": { "key": 84896, "value": 54 }}"""
val rdd = sc.parallelize(Seq(jsonStr))
val df = sqlContext.read.json(rdd)

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