Scala functions defined in JavaBeans

beans.xml

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">

<beans default-lazy-init="true" default-autowire="byName">
    <bean id="increment" class="com.myapp.IntegerFunctions" factory-method="increment" />
    <bean id="decrement" class="com.myapp.IntegerFunctions" factory-method="decrement" />

    <bean id="appendBangs" class="com.myapp.IntegerFunctions" factory-method="lolNoIntegers" />

    <bean id="doubleIncrement" class="com.myapp.IntegersFunctionDoubleApplication">
        <property name="function" ref="increment"/>
    </bean>

    <bean id="doubleDecrement" class="com.myapp.IntegersFunctionDoubleApplication">
        <property name="function" ref="decrement"/>
    </bean>

    <!-- Will pass validation but cause runtime error due to type erasure :( -->
    <bean id="someShit" class="com.myapp.IntegersFunctionDoubleApplication">
        <property name="function" ref="appendBangs"/>
    </bean>
</beans>

IntegerFunctions.scala

package com.myapp

object IntegerFunctions {
  val increment: Int => Int = _ + 1
  val decrement: Int => Int = _ + 1

  val lolNoIntegers: String => String = _ + "!!!"
}

IntegersFunctionDoubleApplication.scala

package com.myapp

import reflect.BeanProperty
import org.springframework.beans.factory.annotation.Required

class IntegersFunctionDoubleApplication {
  @BeanProperty
  @Required
  var function: Int => Int = _

  def applyTwice = function andThen function
}