import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

public class GDS {
	public static void main(String[] args) {
		try {

		URL url = new URL("https://api.geodatasource.com/neighboring-countries?key=Enter_API_Key&format=json&country_code=US");
		HttpURLConnection conn = (HttpURLConnection) url.openConnection();
		conn.setRequestMethod("GET");
		conn.setRequestProperty("Accept", "application/json");

		if (conn.getResponseCode() != 200) {
			throw new RuntimeException("Failed : HTTP error code : " + conn.getResponseCode());
		}

		BufferedReader br = new BufferedReader(new InputStreamReader(
			(conn.getInputStream())));

		String output;

		while ((output = br.readLine()) != null) {
			System.out.println(output);
		}

		conn.disconnect();

	  } catch (MalformedURLException e) {

		e.printStackTrace();

	  } catch (IOException e) {
		e.printStackTrace();
	  }
	}
}

Imports System.Net
Imports System.Security.Cryptography

Partial Public Class _Default
	Inherits System.Web.UI.Page

	Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
		Dim request As HttpWebRequest = Nothing
		Dim response As Net.HttpWebResponse = Nothing
		Dim stream As IO.Stream = Nothing

		Dim apiKey As String = "Enter_API_Key"
		Dim format As String = "json"
		Dim country_code As String = "US"

		request = Net.WebRequest.Create("https://api.geodatasource.com/neighboring-countries?key=" & apiKey & _
		"&format=" & System.Web.HttpUtility.UrlEncode(format) & _
		"&country_code=" & System.Web.HttpUtility.UrlEncode(country_code)

		request.Method = "GET"
		response = request.GetResponse()

		Dim reader As System.IO.StreamReader = New IO.StreamReader(response.GetResponseStream())

		Page.Response.Write(reader.ReadToEnd)
	End Sub
End Class

using Microsoft.VisualBasic;
using System
using System.Collections;
using System.Collections.Generic;
using System.Data;
using System.Diagnostics;
using System.Net;
using System.Security.Cryptography;

public partial class _Default : System.Web.UI.Page
{

	protected void Page_Load(object sender, System.EventArgs e)
	{
		HttpWebRequest request = null;
		System.Net.HttpWebResponse response = null;
		System.IO.Stream stream = null;

		string apiKey = "Enter_API_Key";
		string format = "json";
		string country_code = "US";

		request = System.Net.WebRequest.Create("https://api.geodatasource.com/neighboring-countries?key=" + apiKey + "&format=" + System.Web.HttpUtility.UrlEncode(format) + "&country_code=" + System.Web.HttpUtility.UrlEncode(country_code));

		request.Method = "GET";
		response = request.GetResponse();

		System.IO.StreamReader reader = new System.IO.StreamReader(response.GetResponseStream());

		Page.Response.Write(reader.ReadToEnd());
	}
}

import httplib
import urllib

p = { 'key': 'Enter_API_Key', 'format': 'json', 'country_code': 'US' }

conn = httplib.HTTPConnection("api.geodatasource.com")
conn.request("GET", "/neighboring-countries?" + urllib.urlencode(p))
res = conn.getresponse()
print res.read()

$ curl https://api.geodatasource.com/neighboring-countries?key=Enter_API_Key&format=json&country_code=US

require 'uri'
require 'net/http'

uri = URI.parse("https://api.geodatasource.com/neighboring-countries?key=Enter_API_Key&format=json&country_code=US")
http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = true
request = Net::HTTP::Get.new(uri.request_uri)

response = http.request(request)
print response.body