package modern.challenge; import java.io.IOException; import java.net.URI; import java.net.http.HttpClient; import java.net.http.HttpRequest; import java.net.http.HttpResponse; import java.net.http.HttpHeaders; import java.util.List; import java.util.Optional; public class Main { public static void main(String[] args) throws IOException, InterruptedException { HttpClient client = HttpClient.newHttpClient(); HttpRequest request = HttpRequest.newBuilder() .headers("Content-Type", "application/json") .header("Referer", "https://reqres.in/") .setHeader("X-Auth", "authtoken") .uri(URI.create("https://reqres.in/api/users/2")) .build(); HttpResponse response = client.send(request, HttpResponse.BodyHandlers.ofString()); HttpHeaders allHeaders = response.headers(); System.out.println("All headers: " + allHeaders); List allValuesOfCacheControl = response.headers().allValues("Cache-Control"); System.out.println("All values of Cache-Control: " + allValuesOfCacheControl); Optional firstValueOfCacheControl = response.headers().firstValue("Cache-Control"); System.out.println("First value of Cache-Control: " + firstValueOfCacheControl); } }