-
-
Save DineshQuartic/1b7ac73ac2e61140a0bbbc0f65bb0e4d to your computer and use it in GitHub Desktop.
Generate case class from spark DataFrame/Dataset schema.
This file contains hidden or 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
| /** | |
| * Generate Case class from DataFrame.schema | |
| * | |
| * val df:DataFrame = ... | |
| * | |
| * val s2cc = new Schema2CaseClass | |
| * import s2cc.implicit._ | |
| * | |
| * println(s2cc.schemaToCaseClass(df.schema, "MyClass")) | |
| * | |
| */ | |
| import org.apache.spark.sql.types._ | |
| class Schema2CaseClass { | |
| type TypeConverter = (DataType) => String | |
| def schemaToCaseClass(schema:StructType, className:String)(implicit tc:TypeConverter):String = { | |
| def genField(s:StructField):String = { | |
| val f = tc(s.dataType) | |
| s match { | |
| case x if(x.nullable) => s" ${s.name}:Option[$f]" | |
| case _ => s" ${s.name}:$f" | |
| } | |
| } | |
| val fieldsStr = schema.map(genField).mkString(",\n ") | |
| s""" | |
| |case class $className ( | |
| | $fieldsStr | |
| |) | |
| """.stripMargin | |
| } | |
| object implicits { | |
| implicit val defaultTypeConverter:TypeConverter = (t:DataType) => { t 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 _:ArrayType => "scala.collection.Seq" | |
| case _:MapType => "scala.collection.Map" | |
| case _:StructType => "org.apache.spark.sql.Row" | |
| case _ => "String" | |
| }} | |
| } | |
| } | |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment