INTLanguages & Libraries

How to Use KnoxProxy with Java (HttpClient)

Java HttpClient with proxy support. Configure KnoxProxy using the built-in java.net.http.HttpClient API with ProxySelector.

5 minutes setupVerified against Java (HttpClient) · Jul 2026 · Java 21, HttpClientLanguage: Java

01Steps

Configure Java (HttpClient)

Set proxy

Use ProxySelector for HttpClient.

java

var client = HttpClient.newBuilder()
    .proxy(ProxySelector.of(new InetSocketAddress("gw.knoxproxy.com", 7000)))
    .authenticator(new Authenticator() {
        protected PasswordAuthentication getPasswordAuthentication() {
            return new PasswordAuthentication("USER", "PASS".toCharArray());
        }
    })
    .build();

Make request

Send HTTP request through proxy.

java

var request = HttpRequest.newBuilder(URI.create("https://httpbin.org/ip")).build();
var response = client.send(request, HttpResponse.BodyHandlers.ofString());
System.out.println(response.body());

Country targeting

Modify username.

java

"USER-country-us"

Test

Run and check exit IP.

Error handling

Catch IOException.

java

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

Connection pool

HttpClient reuses connections automatically.

02Values

Copy-paste config

KnoxProxy.java

import java.net.*;
import java.net.http.*;
import java.io.IOException;

public class KnoxProxy {
    public static void main(String[] args) throws IOException, InterruptedException {
        var client = HttpClient.newBuilder()
            .proxy(ProxySelector.of(new InetSocketAddress("gw.knoxproxy.com", 7000)))
            .authenticator(new Authenticator() {
                protected PasswordAuthentication getPasswordAuthentication() {
                    return new PasswordAuthentication("USER", "PASS".toCharArray());
                }
            })
            .build();

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

        var response = client.send(request, HttpResponse.BodyHandlers.ofString());
        System.out.println("Exit IP: " + response.body());
    }
}

Rotation config

HttpClient connection pool may reuse connections. Create a new client per rotation or use -session-{id} in username for explicit session control.

Java (HttpClient) integration troubleshooting guide
Problem	Fix
ConnectException: Connection refused	Verify gw.knoxproxy.com and port 7000.
407 response	Set up Authenticator in HttpClient builder.

Before you start

Prerequisites

Java 11+ (for HttpClient)

No external dependencies

KnoxProxy account

Authentication

Auth method comparison

Username:Password (Authenticator)RecommendedBuilt into Java stdlib. Requires custom Authenticator class

IP AllowlistNo Authenticator needed. Static IP required

All routing lives in the username

Anatomy of the credential string

USER-country-de-city-berlin-session-profile07

country-de -- geo, firstcity-berlin -- optional city pinsession-profile07 -- unique per Java (HttpClient) profile

Order matters -- geo flags before the session flag. The session name is free text; use the profile ID so the mapping is self-documenting. Password stays as issued; no flags belong there. HTTP on :7000, SOCKS5 on :7001, same credentials.

Failure modes & fixes

ConnectException: Connection refused -- Wrong host or port.
407 response -- Authenticator not configured.

Verify before you trust it

IP checker confirms country and ASN match your target
Response status is 200, not 403 or 407
No repeated timeouts on the first few requests
Rotation or stickiness behaves as configured

FAQ

Java (HttpClient) + KnoxProxy, answered

Can I use OkHttp with KnoxProxy?

Yes. Use okhttp3.OkHttpClient.Builder().proxy(Proxy(Proxy.Type.HTTP, InetSocketAddress(host, port))).proxyAuthenticator(...).

Does Java HttpClient support SOCKS5?

Java supports SOCKS via system properties: -DsocksProxyHost=gw.knoxproxy.com -DsocksProxyPort=7001.

How do I use KnoxProxy with Spring Boot?

Configure RestTemplate or WebClient with a custom HttpClient that includes KnoxProxy proxy settings.

What about Apache HttpClient?

Apache HttpClient 5.x supports proxy via HttpClientBuilder.create().setProxy(new HttpHost("gw.knoxproxy.com", 7000)).

RELMore integrations

Start using Java (HttpClient) with KnoxProxy

Free trial on rotating residential -- 5 minutes setup, no credit card.

Start for free See pricing

Configure Java (HttpClient)

Set proxy

Use ProxySelector for HttpClient.

java

var client = HttpClient.newBuilder()
    .proxy(ProxySelector.of(new InetSocketAddress("gw.knoxproxy.com", 7000)))
    .authenticator(new Authenticator() {
        protected PasswordAuthentication getPasswordAuthentication() {
            return new PasswordAuthentication("USER", "PASS".toCharArray());
        }
    })
    .build();

Make request

Send HTTP request through proxy.

java

var request = HttpRequest.newBuilder(URI.create("https://httpbin.org/ip")).build();
var response = client.send(request, HttpResponse.BodyHandlers.ofString());
System.out.println(response.body());

Country targeting

Modify username.

java

"USER-country-us"

Test

Run and check exit IP.

Error handling

Catch IOException.

java

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

Connection pool

HttpClient reuses connections automatically.

Copy-paste config

KnoxProxy.java

import java.net.*;
import java.net.http.*;
import java.io.IOException;

public class KnoxProxy {
    public static void main(String[] args) throws IOException, InterruptedException {
        var client = HttpClient.newBuilder()
            .proxy(ProxySelector.of(new InetSocketAddress("gw.knoxproxy.com", 7000)))
            .authenticator(new Authenticator() {
                protected PasswordAuthentication getPasswordAuthentication() {
                    return new PasswordAuthentication("USER", "PASS".toCharArray());
                }
            })
            .build();

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

        var response = client.send(request, HttpResponse.BodyHandlers.ofString());
        System.out.println("Exit IP: " + response.body());
    }
}

Rotation config

HttpClient connection pool may reuse connections. Create a new client per rotation or use -session-{id} in username for explicit session control.

Java (HttpClient) integration troubleshooting guide
Problem	Fix
ConnectException: Connection refused	Verify gw.knoxproxy.com and port 7000.
407 response	Set up Authenticator in HttpClient builder.

How to Use KnoxProxy with Java (HttpClient)

Configure Java (HttpClient)

Copy-paste config

Prerequisites

Auth method comparison

Anatomy of the credential string

Failure modes & fixes

Verify before you trust it

Java (HttpClient) + KnoxProxy, answered

Related tools

Start using Java (HttpClient) with KnoxProxy

How to Use KnoxProxy with Java (HttpClient)

Configure Java (HttpClient)

Copy-paste config

Prerequisites

Auth method comparison

Anatomy of the credential string

Failure modes & fixes

Verify before you trust it

Java (HttpClient) + KnoxProxy, answered

Related tools

Start using Java (HttpClient) with KnoxProxy