Java操作Html文档利器---Jsoup

一、Jsoup是虾米东西了？这个不解释，给你列个场景你就知道，比喻你现在想通过java代码从www.baidu.com上获取百度icom的url，怎么办了？就必须得对html文档元素进行操作了。对！！Jsoup就是java中用来操作html文档的一个第三方类库。

二、Why Jsoup？用过Jquery的都知道，Jquery简单的语法超强的功能，让人用了就爱不释手，而Jsoup的用法就是使用类Jquery的用法，所以会jQuery的话，稍微看一下文档就会使用Jsoup了。

三、具体应用


    上面罗里吧嗦的简单介绍了一下jsoup，现在简单介绍一下在生产环境中的具体应用。小弟最近遇到的一个需求是通过iTunesId到苹果的网站上去获取这个应用的Icon和描述图片。具体的思路是：
1、从Jsoup的官方网站下载jsoup的jar，最新的版本为1.6.3，并且这个包是无依赖包，不需要和其他的jar包配合使用
2、加载文档
3、查找icon元素获取的地址
4、获取描述图片的元素并取得地址
业务并不复杂，贴一下代码，注释还算清楚。

package com.akwolf.quartz;import java.io.ByteArrayOutputStream;import java.io.IOException;import java.util.ArrayList;import java.util.List;import org.apache.log4j.Logger;import org.jdom.CDATA;import org.jdom.output.Format;import org.jdom.output.XMLOutputter;import org.jsoup.Jsoup;import org.jsoup.nodes.Document;import org.jsoup.nodes.Element;import org.jsoup.select.Elements;import org.quartz.Job;import org.quartz.JobExecutionContext;import org.quartz.JobExecutionException;public class AppleJob implements Job {private static Logger logger = Logger.getLogger(AppleJob.class);public static void main(String[] args) {AppleJob aj = new AppleJob();try {String itunesId = "444934666";try {Document doc = aj.getHtmlDoc(itunesId);logger.debug("itunesId : " + itunesId + " , doc : ");// 如果不是一个有效的链接if (doc == null || !aj.isCorrectItunesId(doc)) {throw new IOException();}String params = aj.getProParameter(aj.getIconUrl(doc),aj.getDescImgUrl(doc));logger.debug("params : " + params);} catch (IOException e) {logger.warn("Can't connect to : " + itunesId);}} catch (Exception e) {e.printStackTrace();logger.warn("Has some Exception!!!");}}@Overridepublic void execute(JobExecutionContext jec) throws JobExecutionException {try {String itunesId = "444934666";try {Document doc = this.getHtmlDoc(itunesId);logger.debug("itunesId : " + itunesId + " , doc : ");// 如果不是一个有效的链接if (doc == null || !isCorrectItunesId(doc)) {throw new IOException();}String params = this.getProParameter(this.getIconUrl(doc),this.getDescImgUrl(doc));logger.debug("params : " + params);} catch (IOException e) {logger.warn("Can't connect to : " + itunesId);}} catch (Exception e) {e.printStackTrace();logger.warn("Has some Exception!!!");JobExecutionException jee = new JobExecutionException(e);jee.refireImmediately();}}/** *  * 判断是否是一个有效的连接 *  * @param doc * @return */private boolean isCorrectItunesId(Document doc) {Elements footer = doc.select("p.footer");if (footer == null || footer.size() == 0) {return true;}return (!"http://www.apple.com.cn/itunes/download/".equals(footer.first().select("a").first().absUrl("href")));}/** * @param iconUrl * @param descImgUrl * @return * @throws IOException *  *  *             拼装出存储过程的参数 */private String getProParameter(String iconUrl, List<String> descImgUrl)throws IOException {StringBuffer buffer = new StringBuffer();org.jdom.Element root = new org.jdom.Element("params");org.jdom.Document doc = new org.jdom.Document(root);org.jdom.Element icon = new org.jdom.Element("IconUrl");org.jdom.Element desc = new org.jdom.Element("DescUrl");ByteArrayOutputStream out = new ByteArrayOutputStream();for (int i = 0; i < descImgUrl.size(); i++) {if (i == descImgUrl.size() - 1) {buffer.append(descImgUrl.get(i));} else {buffer.append(descImgUrl.get(i)).append(",");}}icon.addContent(new CDATA(iconUrl));desc.addContent(new CDATA(buffer.toString()));root.addContent(icon).addContent(desc);Format format = Format.getRawFormat();format.setOmitDeclaration(true);XMLOutputter writer = new XMLOutputter(format);writer.output(doc, out);return out.toString();}/** * @param itunesId * @return * @throws IOException *  *             取得html文档 */private Document getHtmlDoc(String itunesId) throws IOException {Document doc = Jsoup.connect("http://itunes.apple.com/cn/app/id" + itunesId).get();return doc;}/** * @param doc * @return *  *         解析出app的icon图片 */private String getIconUrl(Document doc) {Element img = doc.select("#left-stack").first().select("img").first();String src = img.attr("abs:src");return src;}/** * @param doc * @return *  *         解析出描述图片的url */private List<String> getDescImgUrl(Document doc) {List<String> list = new ArrayList<String>();Elements wrapper = doc.select("div.center-stack").first().select("img.portrait");for (Element element : wrapper) {list.add(element.attr("abs:src"));}return list;}}

结果

26 [main] DEBUG com.akwolf.quartz.AppleJob (2012-09-23 10:50:12,136) - params : <params><IconUrl><![CDATA[http://a3.mzstatic.com/us/r1000/104/Purple/v4/bb/71/3a/bb713a76-5492-9456-5114-63c19582b3c3/mza_297600500225037689.175x175-75.jpg]]></IconUrl><DescUrl><![CDATA[http://a5.mzstatic.com/us/r1000/080/Purple/v4/05/d6/d9/05d6d9d0-686f-63ad-7713-34b5b5aaea7f/mza_2616996279428462004.320x480-75.jpg,http://a2.mzstatic.com/us/r1000/067/Purple/v4/4d/9e/97/4d9e97ea-8367-764d-fceb-e607f55bf847/mza_7946357603060756898.320x480-75.jpg,http://a2.mzstatic.com/us/r1000/071/Purple/v4/21/7a/45/217a4551-d1b1-27e5-3a15-dec47a136069/mza_6366124751766881957.320x480-75.jpg,http://a5.mzstatic.com/us/r1000/065/Purple/v4/7b/5b/ad/7b5badf9-73ba-dd72-4dc9-95a671aa1306/mza_7359786108776115754.320x480-75.jpg,http://a4.mzstatic.com/us/r1000/112/Purple/v4/b7/19/25/b71925c1-a2a7-c69d-fd9c-d3368d0fb1b5/mza_8201700535726140806.320x480-75.jpg]]></DescUrl></params>