本文介绍了HTTPclient POST与有问题的网站的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述

我正在尝试从网站上获取一些数据

我编写了一个Java类,该类在许多站点上似乎都可以正常运行,但不适用于该特定站点,该站点在输入fomr中使用了大量的javascript.

I wrote a java class which seems to work pretty fine with many sites but it doesn't work with this particular site, which use extensive javascript in the input fomr.

从代码中可以看到,我指定了输入字段,这些输入字段取自HTML源代码中的名称,但是也许这个网站不接受这种POST请求?

As you can see from the code I specified the input fields taking the name from the HTML source, but maybe this website doesn't accept POST request of this kind?

如何模拟用户交互以检索生成的HTML?

How can I simulate an user-interaction to retrieve the generated HTML?

package com.transport.urlRetriver;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;

public class UrlRetriver {


    String stationPoller (String url, ArrayList<NameValuePair> params) {

        HttpPost postRequest;
        HttpResponse response;
        HttpEntity entity;
        String result = null;

        DefaultHttpClient httpClient = new DefaultHttpClient();


        try {

            postRequest = new HttpPost(url);

            postRequest.setEntity((HttpEntity) new UrlEncodedFormEntity(params));
            response = httpClient.execute(postRequest);

            entity = response.getEntity();

            if(entity != null){
              InputStream inputStream = entity.getContent();
              result = convertStreamToString(inputStream);
            }



        } catch (Exception e) {

            result = "We had a problem";

        } finally {

            httpClient.getConnectionManager().shutdown();

        }



        return result;

    }





    void ATMtravelPoller () {




        ArrayList<NameValuePair> params = new ArrayList<NameValuePair>(2);

        String url = "http://www.atm-mi.it/it/Pagine/default.aspx";

        params.add(new BasicNameValuePair("ctl00$SPWebPartManager1$g_afa5adbb_5b60_4e50_8da2_212a1d36e49c$txt_address_s", "Viale romagna 1"));

        params.add(new BasicNameValuePair("ctl00$SPWebPartManager1$g_afa5adbb_5b60_4e50_8da2_212a1d36e49c$txt_address_e", "Viale Toscana 20"));

        params.add(new BasicNameValuePair("sf_method", "POST"));

        String result = stationPoller(url, params);

        saveToFile(result, "/home/rachele/Documents/atm/out4.html");

    }

    static void saveToFile(String toFile, String pos){
          try{
                // Create file 
                FileWriter fstream = new FileWriter(pos);
                BufferedWriter out = new BufferedWriter(fstream);
                out.write(toFile);
                //Close the output stream
                out.close();
                }catch (Exception e){//Catch exception if any
                  System.err.println("Error: " + e.getMessage());
                }
              }

    private static String convertStreamToString(InputStream is) {
          BufferedReader reader = new BufferedReader(new InputStreamReader(is));
          StringBuilder stringBuilder = new StringBuilder();

          String line = null;
          try {
            while ((line = reader.readLine()) != null) {
              stringBuilder.append(line + "\n");
            }
          } catch (IOException e) {
            e.printStackTrace();
          } finally {
            try {
              is.close();
            } catch (IOException e) {
              e.printStackTrace();
            }
          }
          return stringBuilder.toString();
        }

}

推荐答案

在我看来,可能是由javascript生成的具有动态值的字段,用于防止自动代码对网站进行爬网.发送您要下载的具体站点.

At my point of view, there could be javascript generated field with dynamic value for preventing automated code to crawl the site. Send concrete site you want to download.

这篇关于HTTPclient POST与有问题的网站的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!

10-20 23:29