WhoIsApiConsumer.java

package org.contributetocommunity.api;

import com.google.gson.Gson;
import org.apache.commons.lang3.StringUtils;

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.util.Arrays;
import java.util.Scanner;

public class WhoIsApiConsumer {

    public static String APIExplorerJava(String ipAddress) {

        String uri = String.format("https://ipwho.is/%s", ipAddress);
        String response = "";

        HttpClient httpClient = HttpClient.newHttpClient();
        HttpRequest httpRequest = HttpRequest.newBuilder(URI.create(uri)).build();

        try {
            HttpResponse<String> httpResponse = httpClient.send(httpRequest, HttpResponse.BodyHandlers.ofString());

            if (httpResponse.statusCode() == 200) {

                Gson gson = new Gson();
                IPInfo ipInfo = gson.fromJson(httpResponse.body(), IPInfo.class);

                if (Boolean.parseBoolean(ipInfo.getSuccess())) {
                    response = String.format("IP %s is located in %s and belongs to %s", ipAddress, ipInfo.getCountry(), ipInfo.getConnection().getIsp())
                            .replace("\"", "");
                } else {
                    response = FailureCases.from(ipInfo.getMessage()).getApiErrorMessage(ipAddress);
                }
            } else {
                response = String.format("Failure: HTTP request failed with status code %d", httpResponse.statusCode());
            }
        } catch (IOException | InterruptedException ex) {
            System.out.println("Failure: " + ex.getMessage());
        }

        return response;
    }

    private enum FailureCases {

        INVALID("Invalid IP address") {
            @Override
            String getApiErrorMessage(String ipAddress) {
                return "Failure: The provided IP " + ipAddress + " is invalid";
            }
        },

        PRIVATE("Reserved range") {
            @Override
            String getApiErrorMessage(String ipAddress) {
                return "Failure: The provided IP " + ipAddress + " is private";
            }
        };

        private final String clientMessage;

        FailureCases(String clientMessage) {
            this.clientMessage = clientMessage;
        }

        abstract String getApiErrorMessage(String ipAddress);

        public static FailureCases from(String value) {
            return Arrays.stream(FailureCases.values())
                    .filter(type -> StringUtils.equalsIgnoreCase(type.clientMessage, value))
                    .findFirst().orElse(INVALID);
        }

    }

    private class IPInfo {

        private String ip;
        private String country;
        private String success;
        private String message;
        private Connection connection;

        public String getIp() {
            return ip;
        }

        public void setIp(String ip) {
            this.ip = ip;
        }

        public String getSuccess() {
            return success;
        }

        public String getCountry() {
            return country;
        }

        public void setCountry(String country) {
            this.country = country;
        }

        public void setSuccess(String success) {
            this.success = success;
        }

        public String getMessage() {
            return message;
        }

        public void setMessage(String message) {
            this.message = message;
        }

        public Connection getConnection() {
            return connection;
        }

        public void setConnection(Connection connection) {
            this.connection = connection;
        }
    }

    private class Connection {

        private String isp;

        public String getIsp() {
            return isp;
        }

        public void setIsp(String isp) {
            this.isp = isp;
        }
    }

    public static void main (String[] args) {
        Scanner s = new Scanner(System.in);
        System.out.print(APIExplorerJava(s.nextLine()));
    }

}