我自己写了一个登录页面，页面上from action一个固定链接，登录成功，进入他的主页面。我想在点击登录时不进他的页面所以我写一个servlet，调用这个方法，我在下面重定向回我的页面。

调用的方法如下：

public static void main(String[] args) throws Exception {
        //cookie存储类
        BasicCookieStore cookieStore = new BasicCookieStore();
        //创建一个httpclient，并设置默认cookie存储cookieStore
        CloseableHttpClient httpclient = HttpClients.custom()
                .setDefaultCookieStore(cookieStore)
                .build();
        try {
            //创建HttpGet对象,需要发送GET请求https://someportal/
            HttpGet httpget = new HttpGet("https://someportal/");
            //HttpClient对象的execute(HttpUriRequest request)发送请求
            CloseableHttpResponse response1 = httpclient.execute(httpget);
            //try开始，试图执行
            try {
                //获取服务器返回的HttpEntity对象
                HttpEntity entity = response1.getEntity();
                //打印返回信息，response.getStatusLine().getStatusCode()==200链接成功，==500失败。
                System.out.println("Login form get: " + response1.getStatusLine());
                //HttpEntity对象提供的静态帮助类,EntityUtils.consume关闭资源
                EntityUtils.consume(entity);
                //打印Initial set of cookies:
                System.out.println("Initial set of cookies:");
                //获取Cookies并循环，空的输出None，否则输出cookie
                List<Cookie> cookies = cookieStore.getCookies();
                if (cookies.isEmpty()) {
                    System.out.println("None");
                } else {
                    for (int i = 0; i < cookies.size(); i++) {
                        System.out.println("- " + cookies.get(i).toString());
                    }
                }
            } finally {
                //关闭
                response1.close();
            }
            //POST请求，并设置URI和参数
            HttpUriRequest login = RequestBuilder.post()
                    .setUri(new URI("https://someportal/"))
                    .addParameter("IDToken1", "username")
                    .addParameter("IDToken2", "password")
                    .build();
            //执行POST请求
            CloseableHttpResponse response2 = httpclient.execute(login);
            try {
                //获取实体对象
                HttpEntity entity = response2.getEntity();
                //打印服务器返回信息
                System.out.println("Login form get: " + response2.getStatusLine());
                //关闭流
                EntityUtils.consume(entity);
                //打印cookie
                System.out.println("Post logon cookies:");
                List<Cookie> cookies = cookieStore.getCookies();
                if (cookies.isEmpty()) {
                    System.out.println("None");
                } else {
                    for (int i = 0; i < cookies.size(); i++) {
                        System.out.println("- " + cookies.get(i).toString());
                    }
                }
            } finally {
                response2.close();
            }
        } finally {
            //关闭httpclient
            httpclient.close();
        }
    }

页面提交参数如下：

　　  String __VIEWSTATE=request.getParameter("__VIEWSTATE");
        String txtPopCorpCode=request.getParameter("txtPopCorpCode");
        String txtPopUserName=request.getParameter("txtPopUserName");
        String htxtPassword=request.getParameter("htxtPassword");
        String txtPopPassword=request.getParameter("txtPopPassword");
        String txtPopCheckCode=request.getParameter("txtPopCheckCode");
        String btnPopLogin=request.getParameter("btnPopLogin");

怎么让这个方法登录成功，怎么知道他成功登录了。并且我需要登录成功后操作这个网站的其他的页面。