使用java的HttpURLConnection模拟登陆百度

public static void loginBaidu()
{
        URL url = null;
        HttpURLConnection httpurlconnection = null;
        try {
            url = new URL(http://www.baidu.com/);
                        httpurlconnection = (HttpURLConnection) url.openConnection();
            httpurlconnection.setRequestProperty("User-Agent", "Internet Explorer");
            httpurlconnection.setRequestProperty("Host", www.baidu.com);
            httpurlconnection.connect();
            String cookie0 = httpurlconnection.getHeaderField("Set-Cookie");
            httpurlconnection.disconnect();
            //String cookie0 = "BAIDUID=8AF5EA24DBF1275CE15C02B5FF65A265:FG=1;
BDSTAT=61a1d3a7118ce8a7ce1b9d16fdfaaf51f3deb48f8e5494eef01f3a292cf5b899; BDUSE=deleted";
            url = new URL(http://passport.baidu.com/?login);
            String strPost = "username=xxxxxx&password=xxxxxx&mem_pass=on";
            httpurlconnection = (HttpURLConnection) url.openConnection();
            httpurlconnection.setFollowRedirects(true);
            httpurlconnection.setInstanceFollowRedirects(true);
            httpurlconnection.setDoOutput(true); // 需要向服务器写数据
            httpurlconnection.setDoInput(true); // 
            httpurlconnection.setUseCaches(false); // 获得服务器最新的信息
            httpurlconnection.setAllowUserInteraction(false);
            httpurlconnection.setRequestMethod("POST");
            httpurlconnection
                    .addRequestProperty(
                            "Accept",
                            "image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, application/x-shockwave-flash, application/msword, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/x-silverlight, */*");
            httpurlconnection.setRequestProperty("Referer", 
                            "http://passport.baidu.com/?login&tpl=mn&u=http%3A//www.baidu.com/");             httpurlconnection.setRequestProperty("Accept-Language", "zh-cn"); 
            httpurlconnection.setRequestProperty("Content-Type",                     "application/x-www-form-urlencoded");             httpurlconnection.setRequestProperty("Accept-Encoding",
                    "gzip, deflate");
            httpurlconnection
                    .setRequestProperty(
                            "User-Agent",
                            "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; Foxy/1; .NET CLR 2.0.50727;
MEGAUPLOAD 1.0)"); 
            httpurlconnection.setRequestProperty("Host", "passport.baidu.com");
            httpurlconnection.setRequestProperty("Content-Length", strPost
                    .length()
                    + "");
            httpurlconnection.setRequestProperty("Connection", "Keep-Alive");
            httpurlconnection.setRequestProperty("Cache-Control", "no-cache");
            httpurlconnection.setRequestProperty("Cookie", cookie0);
            httpurlconnection.getOutputStream().write(strPost.getBytes());
            httpurlconnection.getOutputStream().flush();
            httpurlconnection.getOutputStream().close();
            httpurlconnection.connect();
            int code = httpurlconnection.getResponseCode();
            System.out.println("code   " + code);
            String cookie1 = httpurlconnection.getHeaderField("Set-Cookie");
            System.out.print(cookie0 + "; " + cookie1);
            httpurlconnection.disconnect();

                       url = new URL(http://www.baidu.com/);
                        httpurlconnection = (HttpURLConnection) url.openConnection();
            httpurlconnection.setRequestProperty("User-Agent", "Internet Explorer");
            httpurlconnection.setRequestProperty("Host", www.baidu.com);
            httpurlconnection.setRequestProperty("Cookie", cookie0 + "; " + cookie1);
            httpurlconnection.connect();
            InputStream urlStream = httpurlconnection.getInputStream();
            BufferedInputStream buff = new BufferedInputStream(urlStream);
            Reader r = new InputStreamReader(buff, "gbk");
            BufferedReader br = new BufferedReader(r);
            StringBuffer strHtml = new StringBuffer("");
            String strLine = null;
            while ((strLine = br.readLine()) != null)
{
                strHtml.append(strLine + "\r\n");
            }
            System.out.print(strHtml.toString());
        }
catch (Exception e)
{
            e.printStackTrace();
        }
finally {
            if (httpurlconnection != null)
                httpurlconnection.disconnect();
        }
    }