Parking lot project error: when using a scanner. NoSuchElementException - kotlin

Question

I'll appreciate all your help.
I've been working on a course project where I have to make a parking lot that registers cars. When I use it in my IDE it works fine but when I run it through the platforms tests, in the first one, there's no problem but when the second iteration reaches the "when (val command = scanner.next())" in the createOrder fun, it crashes with the error:
java.lang.AssertionError: Exception in test #1
Probably your program run out of input (Scanner tried to read more than expected).
java.util.NoSuchElementException
at java.util.Scanner.throwFor(Scanner.java:862)
at java.util.Scanner.next(Scanner.java:1371)
at parking.ParkingLot.createOrder(Main.kt:39)
at parking.ParkingLot.start(Main.kt:31)
at parking.MainKt.main(Main.kt:6)
at parking.MainKt.main(Main.kt)
Please find below the output of your program during this failed test.
Note that the '>' character indicates the beginning of the input line.
---
> park KA-01-HH-1234 White
White car parked in spot 1.
the idea is that the test inputs many cars but it crashes when trying to do the second input
this is my code (sorry if my code is messy, I'm still learning)
import java.util.*
fun main() {
ParkingLot.start()
}
class Car(val regNumber: String = "", val color: String = "") {
}
class Order(val command: String) {
lateinit var regNum: String
lateinit var color: String
lateinit var spot: String
lateinit var status: String
}
object ParkingLot {
val spaces: Array<Pair<String?, Car?>> = Array(20) { Pair(null, null) }
const val occupied = "occupied"
const val park = "park"
const val leave = "leave"
const val exit = "exit"
fun start() {
val scanner = Scanner(System.`in`)
do {
val order = createOrder(scanner)
interaction(order, scanner)
} while (order.command != exit)
}
fun createOrder(scanner: Scanner): Order {
when (val command = scanner.next()) {
park -> {
val parkOrder = Order(command)
parkOrder.regNum = scanner.next()
parkOrder.color = scanner.next()
parkOrder.status = "valid"
return parkOrder
}
leave -> {
val retrieveOrder = Order(command)
retrieveOrder.spot = scanner.next()
retrieveOrder.status = "valid"
return retrieveOrder
}
exit -> {
val exitOrder = Order(command)
exitOrder.status = "valid"
return exitOrder
}
else -> {
val incorrectOrder = Order(command)
incorrectOrder.status = "invalid"
return incorrectOrder
}
}
}
fun interaction(order: Order, scanner: Scanner) {
if (order.command == park) {
// val toParkCar = Car(order.regNum, order.color)
park(Car(order.regNum, order.color))
}
if (order.command == leave) {
leave(order)
}
if (order.command == exit) return
//TODO update the error msg to include exit command
if (order.status == "invalid") println("\"${order.command}\" isn't a valid , either use \"park\" or \"leave\"")
// scanner.close()
}
fun park(car: Car) {
for ((index, item) in spaces.withIndex()) {
if (item.first == null) {
spaces[index] = Pair(occupied, car)
println("${car.color} car parked in spot ${index + 1}.")
return
}
}
println("Sorry, the parking lot is full.")
}
fun leave(order: Order) {
if (spaces[order.spot.toInt() - 1].first == occupied) {
spaces[order.spot.toInt() - 1] = Pair(null, null)
println("Spot ${order.spot} is free.")
} else {
println("There is no car in spot ${order.spot}.")
}
}
}

Answer 1

Ok so I noticed this is a problem for the JetBrains plugin. I don't know why but the solution was taking the scanner out of the function and directly in the main loop.