Kotlinで例外クラスの作り方

BadRequestException.kt

class BadRequestExcetpion(val httpStatusCode: String, msg: String? = null): RuntimeException(msg)
// インスタンス生成時にRuntimeExceptionにmsgを渡しています

// Javaで書き直した場合
/*
class BadRequestException extends RuntimeException{
  String httpStatusCode;

   BadRequestException(String httpStatusCode, String msg){
    super(msg)
    this.httpStatusCode = httpStatusCode
   }
 } 
*/

Person.kt

data class Person(
  val name: String,
  val age: Int
  )

PersonController.kt

@RestController
@RequestMapping(value= "/persons")
class PersonController{

    @RequestMapping(value = "/persons/{id}" method = arrayOf(RequestMethod.GET))
    fun getPerson(@PathVariable(value = "id") id: String): Person = 
            when (id){
               "one" -> Person(id, 10),
              "two" -> Person(id, 20),
              else -> throw NotFoundException(403, "Not found Person!!")
            }
  
    @ExceptionHandler(NotFoundException::class)
    @ResponseStatus(HttpStatus.NOT_FOUND)
    fun notFound(e: NotFoundException) : Map<String, String?> =
            mapOf(Pair("status", e.status), Pair("message", e.message))
}