The HTTP OPTIONS function is utilized to depict the correspondence options for the target resource. The client can indicate a URL for the OPTIONS method, or a reference mark, (*), to allude to the whole server.

Here are the common functions of HTTP OPTIONS:

@Throws(RestClientException::class)
fun optionsForAllow(url: String, vararg urlVariables: Any): Set<HttpMethod>

@Throws(RestClientException::class)
fun optionsForAllow(url: String, urlVariables: Map<String, *>): Set<HttpMethod>

@Throws(RestClientException::class)
fun optionsForAllow(url: URI): Set<HttpMethod>

Here is an example of how to call the functions:

val baseUrl: String ?= "YOUR_URL"
val restTemplate = RestTemplate()
val allowHeaders = restTemplate.optionsForAllow(baseUrl)

val uri = URI(baseUrl)
val allowHeadersURI = restTemplate.optionsForAllow(uri)