HtmlCleaner XPath API使用

HtmlCleaner是使用Java编写的HTML解析开源组件。网络上的HTML一般是比较杂乱的，难以进一步处理，需要大量的时间去剔除无效的内容，按照顺序整理tag，attribute等。HtmlCleaner能够将任意的HTML格式化为XML。HtmlCleaner会同浏览器一样默认的创建DOM(Document Object Model)。不论怎样，都需要自定义tag筛选策略和调整方式。

HtmlCleaner可以配置相应的参数（http://htmlcleaner.sourceforge.net/parameters.php），可以在在Java代码中定义，如：

HtmlCleaner cleaner = 
new HtmlCleaner( new ConfigFileTagProvider(myConfigFile) );

也可以在命令行中定义，如：

java -jar htmlcleanerXX.jar [src = <url | file>] [incharset = <charset>] 
[dest = <file>] [outcharset = <charset>] 
[taginfofile = <file>] [options...]

可以通过http://htmlcleaner.sourceforge.net/javause.php，查看基本的用法。

既然HtmlCleaner在内部将HTML组织成XML，那么使用XPath也是理所当然的。作为例子，抓取“豆瓣电影TOP250”

package org.htmlcleaner;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
/**
* @author Reymont.Li
* @DateTime 2015年8月17日 下午6:36:26
*/
public class DoubanTest {
// http://movie.douban.com/top250
// http://movie.douban.com/top250?start=200&filter=&type=
// http://movie.douban.com/top250?start=225&filter=&type=
public static void main(String[] args) throws Exception {
HtmlCleaner cleaner = new HtmlCleaner();
String urlAddr = "http://movie.douban.com/top250";
List<String> names = new ArrayList<String>();
List<String> stars = new ArrayList<String>();
List<String> remarks = new ArrayList<String>();
for (int i = 0; i <= 10; i++) {
TagNode root = cleaner.clean(new URL(urlAddr + "?start=" + i * 25));
Object[] nameArray = root.evaluateXPath("//div[@class='info']//a/span[1]");
for (Object nameNode : nameArray) {
String name = nameNode instanceof TagNode ? ((TagNode) nameNode).getText().toString()
: nameNode.toString();
names.add(name.trim());
}
Object[] starArray = root.evaluateXPath("//div[@class='info']//em");
for (Object starNode : starArray) {
String star = starNode instanceof TagNode ? ((TagNode) starNode).getText().toString()
: starNode.toString();
stars.add(star.trim());
}
Object[] remarkArray = root.evaluateXPath("//div[@class='info']//div[@class='star']/span[2]");
for (Object remarkNode : remarkArray) {
String remark = remarkNode instanceof TagNode ? ((TagNode) remarkNode).getText().toString()
: remarkNode.toString();
remarks.add(remark.trim());
}
}
for (int i = 0; i < names.size(); i++) {
System.out.println(
(i + 1) + "\t name:" + names.get(i) + "\t\t star:" + stars.get(i) + "\t remark:" + remarks.get(i));
}
}
}

参考：

HtmlCleaner Project Home Page

http://htmlcleaner.sourceforge.net/javause.php

htmlcleaner使用及xpath语法初探 - reesun的专栏 - 博客频道 - CSDN.NET

http://blog.csdn.net/reesun/article/details/8021201

Java - XPath解析爬取内容 - 推酷

http://www.tuicool.com/articles/Uzmmue

Java 语言的 XPath API

http://www.ibm.com/developerworks/cn/xml/x-javaxpathapi.html