Java模拟登录并获取Cookie进行访问下一个页面

1. 获取__VIEWSTATE与__EVENTVALIDATION

  /**
     * @return 获取__VIEWSTATE与__EVENTVALIDATION
     */
    public static List getViewstateAndEventvalidation(){


        // 创建远程url连接对象
        HttpURLConnection connection = null;
        InputStream is = null;
        BufferedReader br = null;
        String result = null;  // 返回结果字符串

        try {
            URL url = new URL(loginUrl);
            // 通过远程url连接对象打开一个连接，强转成httpURLConnection类
            connection = (HttpURLConnection) url.openConnection();
            // 设置连接方式：GET
            connection.setRequestMethod("GET");
            // 设置连接主机服务器的超时时间：15000毫秒
            connection.setConnectTimeout(15000);
            // 设置读取远程返回的数据时间：60000毫秒
            connection.setReadTimeout(60000);
            // 发送请求
            connection.connect();
            // 通过connection连接，请求成功后获取输入流
            if (connection.getResponseCode() == 200) {
                is = connection.getInputStream();
                // 封装输入流is，并指定字符集
                br = new BufferedReader(new InputStreamReader(is, "UTF-8"));
                // 存放数据
                StringBuffer sbf = new StringBuffer();
                String temp = null;
                while ((temp = br.readLine()) != null) {
                    sbf.append(temp);
                }
                result = sbf.toString();
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            // 释放资源
            if (null != br) {
                try {
                    br.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (null != is) {
                try {
                    is.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            connection.disconnect();  // 关闭远程连接
        }
        Document doc = Jsoup.parse(result);
        Element viewStateElement = doc.getElementById("__VIEWSTATE");
        Element viewStateElement1 = doc.getElementById("__EVENTVALIDATION");
        String viewStateValue = viewStateElement.attr("value");
        String viewStateValue1 = viewStateElement1.attr("value");
        List params = new ArrayList<>();
        params.add(new BasicNameValuePair("tbxPassWord", password));
        params.add(new BasicNameValuePair("tbxUserId", userName));
        params.add(new BasicNameValuePair("__VIEWSTATE", viewStateValue));
        params.add(new BasicNameValuePair("__EVENTVALIDATION", viewStateValue1));
        params.add(new BasicNameValuePair("ExtCode", ""));
        params.add(new BasicNameValuePair("button_Login", ""));
        return  params;
    }

2.访问下一个链接

返回页面html->Document并且转为字符串

  /**
     * 返回页面html->Document并且转为字符串
     *
     * @param url
     * @return
     */
    public static String getResponseBody(String url) {

        String responseBody = "";
        try {

            // 创建HttpClient对象
            DefaultHttpClient httpClient = new DefaultHttpClient(new PoolingClientConnectionManager());
            HttpPost httpPost = new HttpPost(loginUrl);

            // 添加form-data参数
            List params = getViewstateAndEventvalidation();
            httpPost.setEntity(new UrlEncodedFormEntity(params, "UTF-8"));

            // 执行请求
            HttpResponse response = httpClient.execute(httpPost);
            CookieStore cookieStore = null;
            DefaultHttpClient httpClient1 = new DefaultHttpClient(new PoolingClientConnectionManager());
            //注意，返回的结果的状态码是302，非200
            if (response.getStatusLine().getStatusCode() == 302) {
                // 获取CookieStore
                cookieStore = httpClient.getCookieStore();
                httpClient1.setCookieStore(cookieStore);
            }
            HttpGet nextRequest = new HttpGet(url);

            // 执行下一个连接的请求
            HttpResponse nextResponse = httpClient1.execute(nextRequest);
            // 获取响应内容
            HttpEntity entity1 = nextResponse.getEntity();

            if (entity1 != null) {
                responseBody = EntityUtils.toString(entity1, StandardCharsets.UTF_8);
                // 释放实体内容资源
                EntityUtils.consume(entity1);
            }

            // 关闭HttpClient
            httpClient.close();
            httpClient1.close();
        } catch (Exception e) {
            e.printStackTrace();
        }

        return responseBody;
    }