从模式字符串Java-Spark创建JSON模式 [英] Create JSON schema from schema string Java-Spark

问题描述

我有以下架构:

root
  |-- id: string (nullable = true)
  |-- text: string (nullable = true)  
  |-- user: string (nullable = true)

如何从此字符串创建 StructType 模式?

How can I create StructType schema from this String?

我知道我可以在数据集中使用 .schema()方法，但是我问是否可以从字符串创建模式.

I know that I can use .schema() method in my Dataset but I asking If its possible to create Schema from string.

推荐答案

我需要类似的东西，因此我编写了一个方法，该方法可以从字符串创建模式.但是您必须针对自己的情况更改此方法.

I was need something like that and i wrote a method, this able to creating the schema from string. But you must change this method for your scenario.

val schemaString = "val1#Int val2#String val3#Int"

val schema = StructType(schemaString.split(" ").map(fieldNameTypeStr => {
  val fieldNameType = fieldNameTypeStr.split("#")
  val dataType: DataType = fieldNameType(1) match {
    case "String" => StringType
    case "Int" => IntegerType
      /* other cases */
  }
  StructField(fieldNameType(0), dataType, true)
}))

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