HttpClient抓取【需登录跳转页面】的数据

大家都知道HttpClient可以抓取页面数据，但是有的页面需要用户登录后才可以访问，第一次我用浏览器登录了，把浏览器的Cookie放了进去，可以抓取，但是一天后服务器的Session就过期了，这样很麻烦，后来在网上找了很多资料，才有了下面的版本，下面需要设置两个URL，一个是登录页的，主要是用来获取登录后的Cookie，然后就可以请求第二次的URL了。代码很简单应该大家都可以看懂，我就不解释了。

package cn.amazon.http;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.CookieStore;
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.impl.conn.PoolingClientConnectionManager;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;

//对接口进行测试  
public class getCookie {
    private String loginUrl = "";
    private String SearchUrl = "";
    private String charset = "UTF-8";

    public void test() {
        //存放发送参数
        Map createMap = new HashMap();
        createMap.put("userName", "");
        createMap.put("password", "");
        createMap.put("email", "[email protected]");
        HttpPost httpPost = null;
        HttpPost httpPost2 = null;
        HttpResponse response = null;
        DefaultHttpClient client = null;
        String result = null;
        try {
            client = new DefaultHttpClient(new PoolingClientConnectionManager());
            httpPost = new HttpPost(loginUrl);
            // 设置请求头
            httpPost.setHeader("User-Agent",
                    "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Firefox/45.0");
            // 设置参数
            List list = new ArrayList();
            Iterator iterator = createMap.entrySet().iterator();
            while (iterator.hasNext()) {
                Entry elem = (Entry) iterator.next();
                list.add(new BasicNameValuePair(elem.getKey(), elem.getValue()));
            }
            if (list.size() > 0) {
                UrlEncodedFormEntity entity = new UrlEncodedFormEntity(list, charset);
                httpPost.setEntity(entity);
            }
            // 第一次请求
            response = client.execute(httpPost);
            System.out.println(response);
            // 第二次请求
            httpPost2 = new HttpPost(SearchUrl);
            response = client.execute(httpPost2);
            System.out.println(response);
            // 登录后的请求内容
            if (response != null) {
                HttpEntity resEntity = response.getEntity();
                if (resEntity != null) {
                    result = EntityUtils.toString(resEntity, charset);
                }
            }
            // System.out.println(result);
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }

    public static void main(String[] args) {
        getCookie main = new getCookie();
        main.test();
    }
}