java.io.exception...http exception 403

Can someone help me.I am using the below piece of code for accessing a webpage for which i had access through a browser with some user password authentication. But when i tried the same i got 403 exception, am i doing this wrong?

import java.io.BufferedReader; 
import java.io.InputStreamReader; 
import java.net.URL; 
import java.net.URLConnection; 
import java.net.PasswordAuthentication;开发者_JAVA技巧
import java.net.Authenticator;
import java.net.InetAddress;
import java.lang.reflect.Proxy;
import java.lang.System;
import sun.misc.*;
import java.net.HttpURLConnection;

public class summa { 

    //static final String kuser = " "; // your account name
    static final String kpass = " "; // your password for the account

    //static class MyAuthenticator extends Authenticator {
        //public PasswordAuthentication getPasswordAuthentication() {
            // I haven't checked getRequestingScheme() here, since for NTLM
            // and Negotiate, the usrname and password are all the same.
            //System.err.println("Feeding username and password for " + //getRequestingScheme());
            //return (new PasswordAuthentication(kuser, kpass.toCharArray()));
        //}
    //}

    public static void main(String[] args) { 

        try { 
                URL google = new URL("http://www.google.com/"); 
                HttpURLConnection yc =(HttpURLConnection)google.openConnection(); 
                System.setProperty("http.proxyHost","171.160.82.70") ;   
                System.setProperty("http.proxyPort", "80") ;   
                String userPassword = " ";   
                String encoding = new sun.misc.BASE64Encoder().encode (userPassword.getBytes());   
                //Authenticator.setDefault(new MyAuthenticator());
                yc.setRequestProperty ("Authorization", "Basic " + encoding);   
                yc.setRequestProperty(userPassword, encoding);   
                yc.addRequestProperty("User-Agent","ie-7 (compatible; MSIE 6.0; Windows NT 5.0)"); 

                BufferedReader in = new BufferedReader(new InputStreamReader(yc.getInputStream())); 
                String inputLine="s"; 

                inputLine=in.readLine();
                System.out.println(inputLine); 


                in.close(); 
        } catch (Exception e) { 
            e.printStackTrace(); 
        } 
    } 
}

See HTTP 403: Forbidden.