HttpPost中的VIEWSTATE值

时间:2011-07-22 06:08:51

标签: java asp.net html httpclient http-post

以下是这种情况,我想发布到一个网站,但在此之前我必须检索viewstate值,然后使用此值发布帖子,但问题是每次发帖时viewstate值都在变化,所以如果服务器上的值已经不同,我有点困惑如何在第二篇文章中使用它的值。 有没有解决方案或者我做错了什么?

主要使用httppost

    try {
        HttpClient client = new DefaultHttpClient();

        HttpPost request = new HttpPost(
                "www.website.com/Login.aspx");

        String viewstate = getViewState(client, request,
                "www.website.com/Login.aspx");

        System.out.println(viewstate);

        request.getParams().setBooleanParameter(
                CoreProtocolPNames.USE_EXPECT_CONTINUE, false);
        request.setHeader("Content-Type", "text/html; charset=utf-8");

        List<NameValuePair> postParameters = new ArrayList<NameValuePair>();

        postParameters.add(new BasicNameValuePair("__VIEWSTATE",
                viewstate))
        postParameters.add(new BasicNameValuePair("__EVENTTARGET", ""));
        postParameters.add(new BasicNameValuePair("__EVENTARGUMENT", ""));
        postParameters.add(new BasicNameValuePair("ctl00$tbUsername",
                "name"));
        postParameters
                .add(new BasicNameValuePair("ctl00$tbPwd", "psw"));

        postParameters.add(new BasicNameValuePair("ctl00$chkRememberLogin",
                "0"));
        postParameters
                .add(new BasicNameValuePair("ctl00$cmdLogin", "Login"));

        UrlEncodedFormEntity formEntity = new UrlEncodedFormEntity(
                postParameters);
        request.setEntity(formEntity);
        HttpResponse response = client.execute(request);

        String responseBody2 = EntityUtils.toString(response.getEntity());
        System.out.println(responseBody2);

        }
        // print page wap
        // System.out.println(responseBody2);
    }

然后发送httpget

    String html = "";
    try {

        URL url1 = new URL("www.website.com/Login.aspx");
        URLConnection conn = url1.openConnection();

        // Get the response
        BufferedReader rd = new BufferedReader(new InputStreamReader(
                conn.getInputStream()));
        StringBuffer sb = new StringBuffer();
        String line;
        while ((line = rd.readLine()) != null) {
            sb.append(line+"\n");
        }
        rd.close();
        html = sb.toString();
    } catch (Exception e) {
        e.printStackTrace();
    }

    return findViewstate(html);

所以我在想,也许我应该重复使用相同的httpClient与cookie或任何东西,以便下一个请求将在同一页面...

1 个答案:

答案 0 :(得分:0)

如果我没记错,ViewState值默认是加密的,并且其中包含信息以防止篡改,因此,多个请求将导致不同的值。但是如果你做了一个请求,那么回帖到页面,因为用户你应该没问题,但是你需要确保所有数据都返回,否则你将遇到ASP.NET事件验证的问题。