za.co.absa.enceladus.utils.general.ClassLoaderUtils.scala Maven / Gradle / Ivy
/*
* Copyright 2018 ABSA Group Limited
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package za.co.absa.enceladus.utils.general
import scala.reflect.ClassTag
import scala.reflect.runtime.{universe => ru}
import scala.util.{Failure, Success, Try}
object ClassLoaderUtils {
@throws[IllegalArgumentException]
def loadSingletonClassOfType[T:ClassTag:ru.TypeTag](fullyQualifiedName: String): T = {
val mirror = ru.runtimeMirror(getClass.getClassLoader)
Try(mirror.staticModule(fullyQualifiedName)) match {
case Success(module) => val reflectiveMirror = mirror.reflectModule(module)
Try(reflectiveMirror.instance) match {
case Success(instance) =>
instance match {
case singleton: T => singleton
case _ => throw new IllegalArgumentException(s"Class '$fullyQualifiedName' is not an instance of '${ru.typeOf[T]}'")
}
case Failure(exception) => throw new IllegalArgumentException(s"Class '$fullyQualifiedName' is not a singleton", exception)
}
case Failure(exception) => throw new IllegalArgumentException(s"Class '$fullyQualifiedName' could not be found", exception)
}
}
}