nonfatal是定义非致命错误的scala对象。这里是定义

object NonFatal {
/**

* Returns true if the provided `Throwable` is to be considered non-fatal, or false if it is to be considered fatal
* /

    def apply(t: Throwable): Boolean = t match {
    // VirtualMachineError includes OutOfMemoryError and other fatal errors
    case _: VirtualMachineError | _: ThreadDeath | _: InterruptedException | _: LinkageError | _: ControlThrowable => false
             case _ => true
     }
     /**
     * Returns Some(t) if NonFatal(t) == true, otherwise None
     */
     def unapply(t: Throwable): Option[Throwable] = if (apply(t)) Some(t) else None
}

这意味着抛出的每个异常（除了致命的异常）都将在该案例中被捕获

case NonFatal(e) => println("I want to get to this point")

因为在不适用的情况下，非致命异常是一些（t），而致命异常是无。看到了吗https://docs.scala-lang.org/tour/extractor-objects.html 供参考。
您可以抛出任何非致命异常。