java http proxy settings programatically

gistfile1.txt

import org.apache.commons.io.IOUtils;

import java.io.IOException;
import java.io.InputStream;
import java.net.Authenticator;
import java.net.InetSocketAddress;
import java.net.PasswordAuthentication;
import java.net.Proxy;
import java.net.SocketAddress;
import java.net.URL;
import java.net.URLConnection;

public class TestProxy {

    public static void main(String[] args) throws IOException {
        /* those properties are not reflected by Java's URLConnection */
        System.setProperty("http.proxyUser", "michalb");
        System.setProperty("http.proxyPassword", "password");

        /* this is needed for authentication in case of Java's URLConnection */
        Authenticator.setDefault(new Authenticator() {
            @Override
            protected PasswordAuthentication getPasswordAuthentication() {
                if (getRequestorType() == RequestorType.PROXY) {
                    String prot = getRequestingProtocol().toLowerCase();
                    String host = System.getProperty(prot + ".proxyHost", "");
                    String port = System.getProperty(prot + ".proxyPort", "");
                    String user = System.getProperty(prot + ".proxyUser", "");
                    String password = System.getProperty(prot + ".proxyPassword", "");

                    return new PasswordAuthentication(user, password.toCharArray());

                }
                return null;
            }
        });

        SocketAddress addr = new InetSocketAddress("some.proxy.address.com", 8080);
        Proxy proxy = new Proxy(Proxy.Type.HTTP, addr);

        URL url = new URL("http://www.jsbin.com");
        URLConnection conn = url.openConnection(proxy);

        InputStream inputStream = conn.getInputStream();
        System.out.println(IOUtils.toString(inputStream));
    }
}