标签:执行 byte code getopt 下载 select oid series javascrip
最近在用Jsoup抓取某网站数据,可有些页面是ajax请求动态生成的,去群里问了一下,大神说模拟ajax请求即可。去网上搜索了一下,发现了这篇文章,拿过来先用着试试。
转帖如下:
网上关于网络爬虫实现方式有很多种,但是很多都不支持Ajax,李兄说:模拟才是王道。确实,如果能够模拟一个没有界面的浏览器,还有什么不能做到的呢? 关于解析Ajax网站的框架也有不少,我选择了HtmlUnit,官方网站:http://htmlunit.sourceforge.net /,htmlunit可以说是一个Java版本的无界面浏览器,几乎无所不能,而且很多东西都封装得特别完美。这是这几天来积累下来的心血,记录一下。
package com.lanyotech.www.wordbank; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.net.MalformedURLException; import java.util.List; import com.gargoylesoftware.htmlunit.FailingHttpStatusCodeException; import com.gargoylesoftware.htmlunit.NicelyResynchronizingAjaxController; import com.gargoylesoftware.htmlunit.ScriptResult; import com.gargoylesoftware.htmlunit.WebClient; import com.gargoylesoftware.htmlunit.html.HtmlOption; import com.gargoylesoftware.htmlunit.html.HtmlPage; import com.gargoylesoftware.htmlunit.html.HtmlSelect; public class WorldBankCrawl { private static String TARGET_URL = "http://databank.worldbank.org/ddp/home.do"; public static void main(String[] args) throws FailingHttpStatusCodeException, MalformedURLException, IOException { //模拟一个浏览器 WebClient webClient = new WebClient(); //设置webClient的相关参数 webClient.setJavaScriptEnabled(true); webClient.setCssEnabled(false); webClient.setAjaxController(new NicelyResynchronizingAjaxController()); webClient.setTimeout(35000); webClient.setThrowExceptionOnScriptError(false); //模拟浏览器打开一个目标网址 HtmlPage rootPage= webClient.getPage(TARGET_URL); //获取第一个数据库 HtmlSelect hs = (HtmlSelect) rootPage.getElementById("lstCubes"); //按要求选择第一个数据库 hs.getOption(0).setSelected(true); //模拟点击Next按钮,跳转到第二个页面 System.out.println("正在跳转…"); //执行按钮出发的js事件 ScriptResult sr = rootPage.executeJavaScript("javascript:setCubeData(2,-1,4,‘/ddp‘);"); //跳转到第二个页面,选择国家 HtmlPage countrySelect = (HtmlPage) sr.getNewPage(); //获得包含全部国家信息的选择框页面 HtmlPage framePage=(HtmlPage)countrySelect.getFrameByName("frmTree1″).getEnclosedPage(); //获得selectAll按钮,触发js事件 framePage.executeJavaScript("javascript:TransferListAll(‘countrylst‘,‘countrylstselected‘,‘no‘);SetSelectedCount(‘countrylstselected‘,‘tdcount‘);"); //获取Next按钮,触发js事件 ScriptResult electricityScriptResult = framePage.executeJavaScript("javascript:wrapperSetCube(‘/ddp‘)"); System.out.println("正在跳转…"); //跳转到下一个页面electricitySelect HtmlPage electricitySelect = (HtmlPage) electricityScriptResult.getNewPage(); //获得electricity选择的iframe HtmlPage electricityFrame = (HtmlPage) electricitySelect.getFrameByName("frmTree1″).getEnclosedPage(); //获得选择框 HtmlSelect seriesSelect = (HtmlSelect) electricityFrame.getElementById("countrylst"); //获得所有的选择框内容 List optionList = seriesSelect.getOptions(); //将指定的选项选中 optionList.get(1).setSelected(true); //模拟点击select按钮 electricityFrame.executeJavaScript("javascript:TransferList(‘countrylst‘,‘countrylstselected‘,‘no‘);SetSelectedCount(‘countrylstselected‘,‘tdcount‘);"); //获取选中后,下面的选择框 HtmlSelect electricitySelected = (HtmlSelect) electricityFrame.getElementById("countrylstselected"); List list = electricitySelected.getOptions(); //模拟点击Next按钮,跳转到选择时间的页面 ScriptResult timeScriptResult = electricityFrame.executeJavaScript("javascript:wrapperSetCube(‘/ddp‘)"); System.out.println("正在跳转…"); HtmlPage timeSelectPage = (HtmlPage) timeScriptResult.getNewPage(); //获取选中时间的选择框 timeSelectPage = (HtmlPage) timeSelectPage.getFrameByName("frmTree1″).getEnclosedPage(); //选中所有的时间 timeSelectPage.executeJavaScript("javascript:TransferListAll(‘countrylst‘,‘countrylstselected‘,‘no‘);SetSelectedCount(‘countrylstselected‘,‘tdcount‘);"); //点击Next按钮 ScriptResult exportResult = timeSelectPage.executeJavaScript("javascript:wrapperSetCube(‘/ddp‘)"); System.out.println("正在跳转…"); //转到export页面 HtmlPage exportPage = (HtmlPage) exportResult.getNewPage(); //点击页面上的Export按钮,进入下载页面 ScriptResult downResult = exportPage.executeJavaScript("javascript:exportData(‘/ddp‘ ,‘EXT_BULK‘ ,‘WDI_Time=51||WDI_Series=1||WDI_Ctry=244||‘ );"); System.out.println("正在跳转…"); HtmlPage downLoadPage = (HtmlPage) downResult.getNewPage(); //点击Excel图标,开始下载 ScriptResult downLoadResult = downLoadPage.executeJavaScript("javascript:exportData(‘/ddp‘,‘BULKEXCEL‘);"); //下载Excel文件 InputStream is = downLoadResult.getNewPage().getWebResponse().getContentAsStream(); OutputStream fos = new FileOutputStream("d://test.xls"); byte[] buffer=new byte[1024*30]; int len=-1; while((len=is.read(buffer))>0){ fos.write(buffer, 0, len); } fos.close(); fos.close(); System.out.println("Success!"); } }
注释:
/**HtmlUnit请求web页面*/ WebClient wc = new WebClient(); wc.getOptions().setJavaScriptEnabled(true); //启用JS解释器,默认为true wc.getOptions().setCssEnabled(false); //禁用css支持 wc.getOptions().setThrowExceptionOnScriptError(false); //js运行错误时,是否抛出异常 wc.getOptions().setTimeout(10000); //设置连接超时时间 ,这里是10S。如果为0,则无限期等待 HtmlPage page = wc.getPage("http://cq.qq.com/baoliao/detail.htm?294064"); String pageXml = page.asXml(); //以xml的形式获取响应文本
标签:执行 byte code getopt 下载 select oid series javascrip
原文地址:http://www.cnblogs.com/printN/p/7258696.html