Java

HttpClient (Java 11+)

import java.net.*;
import java.net.http.*;

public class ProxyExample {
    public static void main(String[] args) throws Exception {
        var proxy = ProxySelector.of(
            new InetSocketAddress("connect.trueproxies.com", 8080)
        );

        Authenticator.setDefault(new Authenticator() {
            protected PasswordAuthentication getPasswordAuthentication() {
                return new PasswordAuthentication(
                    "your_username", "your_password".toCharArray()
                );
            }
        });

        var client = HttpClient.newBuilder()
            .proxy(proxy)
            .authenticator(Authenticator.getDefault())
            .build();

        var request = HttpRequest.newBuilder()
            .uri(URI.create("https://httpbin.org/ip"))
            .build();

        var response = client.send(request, HttpResponse.BodyHandlers.ofString());
        System.out.println(response.body());
    }
}

HttpURLConnection

import java.io.*;
import java.net.*;

public class ProxyExample {
    public static void main(String[] args) throws Exception {
        Proxy proxy = new Proxy(Proxy.Type.HTTP,
            new InetSocketAddress("connect.trueproxies.com", 8080));

        Authenticator.setDefault(new Authenticator() {
            protected PasswordAuthentication getPasswordAuthentication() {
                return new PasswordAuthentication(
                    "your_username", "your_password".toCharArray()
                );
            }
        });

        URL url = new URL("https://httpbin.org/ip");
        HttpURLConnection conn = (HttpURLConnection) url.openConnection(proxy);

        BufferedReader reader = new BufferedReader(
            new InputStreamReader(conn.getInputStream())
        );
        String line;
        while ((line = reader.readLine()) != null) {
            System.out.println(line);
        }
        reader.close();
    }
}

Country Targeting

return new PasswordAuthentication(
    "your_username-country-us", "your_password".toCharArray()
);