HttpClient、HTMLParser解决Google搜索结果的页面无法解析问题

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      原先一个对google、百度的搜索页面简单解析处理的小程序，前几天突然发现对google的搜索结果处理不起作用了，百度的一切正常。经测试估计是google做了相应的限制，后来便想到了先用httpclient模拟客户端访问，获取搜索结果的页面，然后再用HTMLParser处理。
      HttpClient 是 Apache Jakarta Common 下的子项目，可以用来提供高效的、最新的、功能丰富的支持 HTTP 协议的客户端编程工具包，网站：http://hc.apache.org/

问题解决前后的测试代码如下：
原先的代码TestGoogleSearch.java：

package com.htmlparser;

import java.net.HttpURLConnection;
import java.net.URL;

import org.htmlparser.NodeFilter;
import org.htmlparser.Parser;
import org.htmlparser.filters.TagNameFilter;
import org.htmlparser.tags.LinkTag;
import org.htmlparser.util.NodeList;

/**
 * 测试 google 搜索结果页面处理
 * @author Michael
 * 
 */
public class TestGoogleSearch {

    /**
     * @param args
     */
    public static void main(String[] args) {
        TestGoogleSearch test = new TestGoogleSearch();
        String url = "http://www.google.com.hk/search?hl=zh-CN&source=hp&q=nero9%E5%88%BB%E5%BD%95ape&aq=f&aqi=&aql=&oq=&gs_rfai=";
        test.parseLinkFilter(url);

    }

    /**
     * 
     * @param url
     */
    private void parseLinkFilter(String url) {
        System.out.println("NodeFilter start...");
        try {
            HttpURLConnection.setFollowRedirects(true);
            URL netUrl = new URL(url);
            HttpURLConnection con = (HttpURLConnection) netUrl.openConnection();
            con.setInstanceFollowRedirects(false);
            con.connect();
            Parser parser = new Parser(con);
            parser.setEncoding(parser.getEncoding());

            NodeFilter filter = new TagNameFilter("A");
            NodeList list = parser.extractAllNodesThatMatch(filter);
            for (int i = 0; i < list.size(); i++) {
                LinkTag tag = (LinkTag) list.elementAt(i);
                System.out.println(tag.getLinkText() + " -- " + tag.getLink());
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

        System.out.println("NodeFilter end");
    }
}

运行结果：
NodeFilter start...
here -- http://www.google.com.hk/url?sa=p&hl=zh-CN&cki=PREF%3DID%3Db49ef17c9c585188:FF%3D1:LD%3Dzh-CN:NW%3D1:TM%3D1288754215:LM%3D1288754215:S%3DDvpSJRMCSGZqN7mE&q=http://www.google.com.hk/search%3Fhl%3Dzh-CN%26source%3Dhp%26q%3Dnero9%25E5%2588%25BB%25E5%25BD%2595ape%26aq%3Df%26aqi%3D%26aql%3D%26oq%3D%26gs_rfai%3D&ust=1288754245627953&usg=AFQjCNFqlSLKTXZTp3Vk7WcVsOHOkhNeMQ
NodeFilter end

从打印结果会发现只能解析出一个google自身的连接

修改后的代码TestParserGoogleSearch.java：

package com.htmlparser;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

import org.apache.commons.httpclient.DefaultHttpMethodRetryHandler;
import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpException;
import org.apache.commons.httpclient.HttpStatus;
import org.apache.commons.httpclient.methods.GetMethod;
import org.apache.commons.httpclient.params.HttpMethodParams;
import org.htmlparser.Parser;
import org.htmlparser.filters.TagNameFilter;
import org.htmlparser.tags.LinkTag;
import org.htmlparser.util.NodeList;

/**
 * 
 * @author Michael
 * 
 */
public class TestParserGoogleSearch {

    /**
     * @param args
     */
    public static void main(String[] args) {
        TestParserGoogleSearch parser = new TestParserGoogleSearch();
        String url = "http://www.google.com.hk/search?hl=zh-CN&source=hp&q=nero9%E5%88%BB%E5%BD%95ape&aq=f&aqi=&aql=&oq=&gs_rfai=";
        String html = parser.getUrlHtmlByHttpClient(url);
        parser.parseHtmlLink(html);
    }

    /**
     * 处理搜索结果字符串
     * @param htmlstr
     */
    private void parseHtmlLink(String htmlstr) {
        try {
            Parser parser = Parser.createParser(htmlstr, "utf-8");

            // 创建TagNameFilter实例
            TagNameFilter filter = new TagNameFilter("A");
            // 筛选出所有A标签节点
            NodeList nodes = parser.extractAllNodesThatMatch(filter);
            if (nodes != null) {
                System.out.println(nodes.size());
                for (int i = 0; i < nodes.size(); i++) {
                    LinkTag tag = (LinkTag) nodes.elementAt(i);
                    System.out.println(tag.getLinkText() + " -- "
                            + tag.getLink());
                }

            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * 模拟客户端访问获取搜索结果页面
     * @param url
     * @return
     */
    private String getUrlHtmlByHttpClient(String url) {
        String searchHtml = null;
        HttpClient httpClient = new HttpClient();
        httpClient.getHttpConnectionManager().getParams().setConnectionTimeout(
                5000);
        GetMethod getMethod = new GetMethod(url);
        getMethod.getParams().setParameter(HttpMethodParams.SO_TIMEOUT, 5000);
        getMethod.getParams().setParameter(HttpMethodParams.RETRY_HANDLER,
                new DefaultHttpMethodRetryHandler());
        try {
            int statusCode = httpClient.executeMethod(getMethod);
            if (statusCode != HttpStatus.SC_OK) {
                System.err.println("Method failed: "
                        + getMethod.getStatusLine());
            }
            InputStream bodyIs = getMethod.getResponseBodyAsStream();//
            System.out.println("get reoponse body stream:" + bodyIs);

            //如果中文乱码 修改字符集
            // BufferedReader br = new BufferedReader(
            // new InputStreamReader(bodyIs,"GBK"));
            BufferedReader br = new BufferedReader(
                    new InputStreamReader(bodyIs));
            StringBuffer sb = new StringBuffer();
            String line = null;
            while ((line = br.readLine()) != null) {
                sb.append(line);
            }
            searchHtml = sb.toString();
            return searchHtml;
        } catch (HttpException e) {
            System.out.println("Please check your http address!");
            e.printStackTrace();
            return null;
        } catch (IOException e) {
            e.printStackTrace();
            return null;
        } finally {
            getMethod.releaseConnection();
        }

    }

}

运行结果：
get reoponse body stream:org.apache.commons.httpclient.AutoCloseInputStream@193385d
85
图片 -- http://www.google.com.hk/images?hl=zh-cn&q=nero9%E5%88%BB%E5%BD%95ape&um=1&ie=UTF-8&source=og&sa=N&tab=wi
视频 -- http://www.google.com.hk/search?hl=zh-cn&q=nero9%E5%88%BB%E5%BD%95ape&um=1&ie=UTF-8&tbo=u&tbs=vid:1&source=og&sa=N&tab=wv
。。。。。。 省略一些打印结果
这样可以解析出所有的连接，加上相应的参数也可以翻页。

OK，到此就是基本的解决过程了，希望能给某位需要的仁兄提供帮助。