Get top domain from URL

TopDomainExtractor.java

package example;

import com.google.common.net.InternetDomainName;
import org.springframework.stereotype.Service;
import org.springframework.web.util.UriComponentsBuilder;

@Service
public class TopDomainExtractor {
    public String getTopDomain(String requestUrl) {
        try {
            var host = UriComponentsBuilder.fromUriString(requestUrl).build().getHost();
            return InternetDomainName.from(host).topPrivateDomain().toString();
        } catch (IllegalStateException | NullPointerException e) {
            throw new IllegalArgumentException("Cannot extract top domain from '" + requestUrl + "'", e);
        }
    }
}