Galera programa de curso "proxy"

Programação Java
#1

ola galera tenho q fazer um proxy e estou meio perdido. procurei no google e aqui no forum e o achei foi um codigo q nao sei fazer funcionar algume pode me ajudar a fazer um proxy?

galera agora vendo melhor esse codigo e para a aplicação passar por um proxy nao é?

import java.util.Properties;
import java.util.Date;
import java.net.URL;
import java.net.URLEncoder;
import java.net.HttpURLConnection;
import java.net.URLConnection;
import java.io.DataInputStream;
import java.io.DataOutputStream;

// This is a simple example that shows how to get HTTP connections to work
// with a proxy server. If all goes well, we should be able to post some
// data to a public cgi script and get back the resulting HTML.  If anyone 
// knows some "gotchas" when combining Java and proxies, I'd love to hear
// about them.  Send your thoughts to kurr@ctron.com. 

public class ProxyTest
{
    public static void main( String argv[] )
    {
        try
        {
            // Enable the properties used for proxy support
            System.getProperties().put( "proxySet", "true" );
            System.getProperties().put( "proxyHost", "proxy2" );
            System.getProperties().put( "proxyPort", "85" );

            // URL to a public cgi script
            URL url = new URL("http://hoohoo.ncsa.uiuc.edu/cgi-bin/post-query/");
            URLConnection connection = url.openConnection();

            // enter the username and password for the proxy
            String password = "username:password";

            // base64 encode the password.  You can write your own,
            // use a public domain library like
            // http://www.innovation.ch/java/HTTPClient/ or use 
            // the sunw.server.admin.toolkit.security.BASE64Encoder
            // class from JavaSoft Java Web Server.
            String encoded = base64Encode( password );

            // Set up the connection so it knows you are sending
            // proxy user information
            connection.setRequestProperty( "Proxy-Authorization", encoded );

            // Set up the connection so you can do read and writes 
            connection.setDoInput( true );
            connection.setDoOutput( true );

            // open up the output stream of the connection
            DataOutputStream output = new DataOutputStream( 
                                       connection.getOutputStream() ); 

            // simulate a POST from a web form
            String query =  "name=" + URLEncoder.encode( 
                            "Ronald D. Kurr" );
            query += "&";
            query += "email=" + URLEncoder.encode( "kurr@ctron.com" );

            // write out the data
            int queryLength = query.length();
            output.writeBytes( query );
            output.close();

            // get ready to read the response from the cgi script
            DataInputStream input = new DataInputStream( 
                                       connection.getInputStream() ); 

            // read in each character until end-of-stream is detected
            for( int c = input.read(); c != -1; c = input.read() )
            {
                System.out.print( (char)c );
            }
            input.close();
        }
        catch( Exception e )
        {
            System.out.println( "Something bad just happened." );
            System.out.println( e );
            e.printStackTrace();
        }
    }
}

grato

#2