CallMethodViaReflection Expression¶

CallMethodViaReflection is a non-deterministic expression that represents a static method call (in Scala or Java) using reflect and java_method standard functions.

CallMethodViaReflection supports fallback mode for expression code generation.

Creating Instance¶

CallMethodViaReflection takes the following to be created:

Children Expressions

CallMethodViaReflection is created when:

reflect standard function is used

evalInternal¶

Nondeterministic

evalInternal(
  input: InternalRow): Any

evalInternal is part of the Nondeterministic abstraction.

evalInternal...FIXME

initializeInternal¶

Nondeterministic

initializeInternal(
  partitionIndex: Int): Unit

initializeInternal is part of the Nondeterministic abstraction.

initializeInternal...FIXME

Demo¶

import org.apache.spark.sql.catalyst.expressions.CallMethodViaReflection
import org.apache.spark.sql.catalyst.expressions.Literal
val expr = CallMethodViaReflection(
  Literal("java.time.LocalDateTime") ::
  Literal("now") :: Nil)

scala> println(expr.numberedTreeString)
00 reflect(java.time.LocalDateTime, now, true)
01 :- java.time.LocalDateTime
02 +- now

val q = """SELECT reflect("java.time.LocalDateTime", "now") AS now"""
val plan = spark.sql(q).queryExecution.logical

// CallMethodViaReflection shows itself under "reflect" name
scala> println(plan.numberedTreeString)
00 'Project ['reflect(java.time.LocalDateTime, now) AS now#0]
01 +- OneRowRelation