spring conversion helpers for scala

Conversions.scala

package com.solarmosaic.core.service.converter

import javax.inject.Inject

import org.springframework.beans.factory.annotation.Qualifier
import org.springframework.core.convert.{TypeDescriptor, ConversionService}

import scala.reflect._

/**
 * Converts from type `A` to type `B` using the given ConversionService.
 *
 * @param from The object to convert from.
 * @param conversionService The ConversionService
 * @tparam A Type to convert from
 */
class Conversion[A: ClassTag](from: A, conversionService: ConversionService) {

  /**
   * Performs conversion from type `A` to type `B`.
   *
   * @tparam B The type to convert to.
   * @return An instance of the class we are converting to.
   */
  def convertTo[B: ClassTag]: B = {
    val sourceType = classTag[A].runtimeClass.asInstanceOf[Class[A]]
    val targetType = classTag[B].runtimeClass.asInstanceOf[Class[B]]

    conversionService
      .convert(from, TypeDescriptor.valueOf(sourceType), TypeDescriptor.valueOf(targetType))
      .asInstanceOf[B]
  }
}

/**
 * Extend this trait to provide automatic conversions inside your class.
 */
trait Conversions {
  import scala.language.implicitConversions

  /**
   * Provides a `ConversionService` for use inside REST controllers. This needs to be qualified specifically for
   * use by Spring MVC to prevent collisions with other `ConversionService` objects Spring boot supplies automatically.
   */
  @Inject
  @Qualifier("mvcConversionService")
  var conversionService: ConversionService = _

  /**
   * Implicitly provide conversions for the given type `A`.
   *
   * @param from The object to convert from.
   * @tparam A The type of the object.
   * @return The Conversion class for type `A`.
   */
  implicit def toConversion[A: ClassTag](from: A): Conversion[A] = new Conversion[A](from, conversionService)
}