Proxy setup in Java

A step-by-step guide to connecting Prokso proxies in Java. It takes a few minutes.

Step 1. Get the proxy details from your dashboard

Open your plan and copy the host gw.prokso.com, port, username and password. Port 823 is HTTP and 824 is SOCKS5 (both give a new IP for every request); ports 10000–20000 keep one IP (sticky session) for up to 120 minutes and work as both HTTP and SOCKS5 (each port is a separate address). Set the country in the username: username__cr.ua.

Step 2. Use Java 11 or later

The example uses the built-in java.net.http.HttpClient, available in the JDK since version 11. No third-party libraries are needed.

Step 3. Enable Basic auth for the tunnel

By default the JDK doesn't send the proxy username and password when it opens an https website through a tunnel, and the request fails with a 407 error. The jdk.http.auth.tunneling.disabledSchemes system property set to an empty value turns it on. Set it at the very start of the program, as in the example, or with the launch flag -Djdk.http.auth.tunneling.disabledSchemes=.

import java.net.Authenticator;
import java.net.InetSocketAddress;
import java.net.PasswordAuthentication;
import java.net.ProxySelector;
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.time.Duration;

public class Main {
    public static void main(String[] args) throws Exception {
        System.setProperty("jdk.http.auth.tunneling.disabledSchemes", "");

        HttpClient client = HttpClient.newBuilder()
                .proxy(ProxySelector.of(new InetSocketAddress("gw.prokso.com", 823)))
                .authenticator(new Authenticator() {
                    @Override
                    protected PasswordAuthentication getPasswordAuthentication() {
                        return new PasswordAuthentication("USERNAME", "PASSWORD".toCharArray());
                    }
                })
                .connectTimeout(Duration.ofSeconds(30))
                .build();

        HttpRequest request = HttpRequest.newBuilder(URI.create("https://api.ipify.org?format=json")).build();
        System.out.println(client.send(request, HttpResponse.BodyHandlers.ofString()).body());
    }
}

Step 4. Give the client the proxy and credentials

ProxySelector.of sets the proxy address and an Authenticator supplies the username and password. HttpClient answers the proxy's authentication challenge on its own. Create the client once and reuse it for all requests.

Step 5. SOCKS5 and a sticky IP

HttpClient only works with HTTP proxies. For SOCKS5 you need the older HttpURLConnection with a java.net.Proxy of type SOCKS on port 824 and the same Authenticator installed with Authenticator.setDefault. For a series of requests from one IP, switch to a sticky port from 10000-20000.

Step 6. If the connection fails

Check the host gw.prokso.com, the port and the scheme: HTTP on 823, SOCKS5 on 824, either one on ports 10000-20000. A 407 error means a wrong username or password, or the plan has run out of traffic: check the balance on the plan page in your dashboard. A timeout most often means a typo in the port or a client expecting a different protocol. If you use the IP whitelist, make sure the external address of the exact machine running the code is on the list.

Step 7. Check the output

Run the example: the program calls https://api.ipify.org and prints the IP the website sees. It should be the proxy's address, not yours. A 407 error means a wrong username or password, or the plan has run out of traffic. The My IP page in your browser won't help here: the browser goes direct.