In `spring boot` I'm trying to use `RestTemplate` ...

# getting-started

[ursus]

In spring boot I'm trying to use RestTemplate in tests to simply call requests and assert responses.
There are kotlin extensions available for getForObject

@Throws(RestClientException::class)
inline fun <reified T : Any> TestRestTemplate.getForObject(url: String, vararg uriVariables: Any): T? =
		getForObject(url, T::class.java, *uriVariables)

However when I use it with a List it breaks

val people = client.getForObject<List<Person>>("/people")

When I hook up debugger the people variable is of type List and then element is LinkedHashMap

If then in debugger I evaluate people.first() I get a class cast exception

Anyone know what's up?

[ephemient]

that means it's a List containing something which isn't a Person. due to generic erasure that can't be checked until the item is retrieved

[ursus]

That makes sense but now what, I cannot use endpoints returning a list at all?

[ephemient]

same as Java, there is another form which will preserve the generic type information which Class<*> does not retain

exchange(url, GET, null, object : ParameterizedTypeReference<List<Person>>() {}, *uriVariables)