gistfile1.java

import com.squareup.okhttp.OkHttpClient;
import com.squareup.okhttp.Request;
import com.squareup.okhttp.Response;

import java.io.IOException;
import java.net.*;
import java.util.ArrayList;
import java.util.List;

public class ProxyTest {

    private static class CustomProxySelector extends ProxySelector {

        private final List<Proxy> proxies = new ArrayList<>();

        public CustomProxySelector() {
            proxies.add(new Proxy(Proxy.Type.HTTP, new InetSocketAddress("127.0.0.1", 8080)));
        }

        @Override
        public List<Proxy> select(URI uri) {
            return proxies;
        }

        @Override
        public void connectFailed(URI uri, SocketAddress sa, IOException ioe) {
            throw new RuntimeException("CONNECTION FAILED");
        }
    }

    public static void main(final String... arguments) throws Exception {
        CustomProxySelector selector = new CustomProxySelector();
        ProxySelector.setDefault(selector);
        URL url = new URL("http://www.example.com/");
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
        connection.connect();
        ByteString byteString = Okio.buffer(Okio.source(connection.getInputStream())).readByteString();
        System.out.printf("HttpURLConnection response:%n%s%n", byteString.utf8());
        OkHttpClient client = new OkHttpClient();
        Request request = new Request.Builder().url(url).build();
        Response response = client.newCall(request).execute();
        System.out.printf("OkHttpClient response:%n%s%n", response.body().string());
    }
}