Created
February 27, 2020 08:46
-
-
Save BioQwer/33bd0bcacea7236441dafff4da5de4cf to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
/** | |
* println(Schema2CaseClass.schema2Cc(dfp.schema, "Party")) | |
*/ | |
object Schema2CaseClass { | |
import org.apache.spark.sql.types._ | |
case class RecFieldRes(fieldStr: String, additionalCc: Option[String] = None) | |
case class CcRes(cc: String, additional: List[String]) | |
def schema2Cc(schema: StructType, className: String): String = { | |
val res = CcRes(s"case class $className (\n", Nil) | |
val res1 = schema.map(field).foldLeft(res)((b, a) => b.copy(b.cc + s"\n${a.fieldStr},", b.additional ++ a.additionalCc)) | |
res1.cc.stripSuffix(",") + "\n)\n" + res1.additional.mkString("\n\n") | |
} | |
private def field(sf: StructField): RecFieldRes = { | |
def fd: String => String = fieldDef(sf) | |
sf.dataType match { | |
case at: ArrayType => at.elementType match { | |
case s: StructType => RecFieldRes(fd(s"Seq[${sf.name.toLowerCase.capitalize}]"), Some(schema2Cc(s, sf.name.toLowerCase.capitalize))) | |
case _ => RecFieldRes(fd(s"Seq[${primitiveFiledType(at.elementType)}]")) | |
} | |
case mt: MapType => RecFieldRes(fd("Map")) //TODO | |
case st: StructType => RecFieldRes(fd(sf.name.toLowerCase.capitalize), Some(schema2Cc(st, sf.name.toLowerCase.capitalize))) | |
case pt => RecFieldRes(fd(primitiveFiledType(pt))) | |
} | |
} | |
private def primitiveFiledType(dt: DataType): String = dt match { | |
case _: ByteType => "Byte" | |
case _: ShortType => "Short" | |
case _: IntegerType => "Int" | |
case _: LongType => "Long" | |
case _: FloatType => "Float" | |
case _: DoubleType => "Double" | |
case _: DecimalType => "java.math.BigDecimal" | |
case _: StringType => "String" | |
case _: BinaryType => "Array[Byte]" | |
case _: BooleanType => "Boolean" | |
case _: TimestampType => "java.sql.Timestamp" | |
case _: DateType => "java.sql.Date" | |
case _ => "String" | |
} | |
private def fieldDef(sf: StructField)(ft: String): String = sf match { | |
case x if x.nullable && !x.dataType.isInstanceOf[ArrayType] && !x.dataType.isInstanceOf[MapType] => | |
s""" ${if(sf.name=="type") "`type`" else sf.name }: Option[$ft]""" | |
case _ => s" ${sf.name}: $ft" | |
} | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment