"Lambdifying" scala Function in Java -

using java , apache spark (that has been rewritten in scala), faced old api method (org.apache.spark.rdd.jdbcrdd constructor), has abstractfunction1 it's argument:

abstract class abstractfunction1[@scala.specialized -t1, @scala.specialized +r]() extends scala.anyref scala.function1[t1, r] {} 

because abstractfunction1 abstract class, cant use java8 lambdas, decided wrap scala.function1 trait same java.util.functions.function does't implements andthen , compose methods. result, create thes interface:

import scala.function1;  @functionalinterface public interface funct<t, r> extends function1<t, r>, serializable {      @override     default <a> function1<a, r> compose(function1<a, t> before) {         return null;     }      @override     default <a> function1<t, a> andthen(function1<r, a> g) {         return null;     } } 

ide has no problems interface, while compiling, get:

[error] funct not functional interface [error] multiple non-overriding abstract methods found in interface funct 

is possible wrap scala's trait, can use lambdas method:

void domagic(scala.function1<t,v> arg) 

so want functional interface version of scala function traits can call them java8 lambda syntax? don't have yourself. take @ https://github.com/scala/scala-java8-compat . not quite nice directly using java8 lambda syntax, since still have do

import static scala.compat.java8.jfunction.*; domagic(func(x => ...)); 

instead of

domagic(x => ...); 

but in scala 2.12 big theme java8 compatibility. scala functionx classes redone sam interfaces, able latter when scala 2.12 comes out. @ least plan last time checked.