使用Jsoup抽取数据Jsoup是一个Java的HTML解析器，提供了非常方便的抽取和操作HTML文档方法，可以结合DOM，CSS
使用Jsoup抽取数据
Jsoup是一个Java的HTML解析器，提供了非常方便的抽取和操作HTML文档方法，可以结合DOM，CSS和Jquery类似的方法来定位和得到节点的信息。
有着和Jquery一样强大的select和pipeline的API。
我们以从58同城网抽取租房信息为例,来说明如何使用它：
Selector overview
* tagname: find elements by tag, e.g. a
* ns|tag: find elements by tag in a namespace, e.g. fb|name finds <fb:name> elements
* #id: find elements by ID, e.g. #logo
* .class: find elements by class name, e.g. .masthead
* [attribute]: elements with attribute, e.g. [href]
* [^attr]: elements with an attribute name prefix, e.g. [^data-] finds elements with HTML5 dataset attributes
* [attr=value]: elements with attribute value, e.g. [width=500]
* [attr^=value], [attr$=value], [attr*=value]: elements with attributes that start with, end with, or contain the value, e.g. [href*=/path/]
* [attr~=regex]: elements with attribute values that match the regular expression; e.g. img[src~=(?i)\.(png|jpe?g)]
* *: all elements, e.g. *
Selector combinations
* el#id: elements with ID, e.g. div#logo
* el.class: elements with class, e.g. div.masthead
* el[attr]: elements with attribute, e.g. a[href]
* Any combination, e.g. a[href].highlight
* ancestor child: child elements that descend from ancestor, e.g. .body p finds p elements anywhere under a block with class "body"
* parent > child: child elements that descend directly from parent, e.g. div.content > p finds p elements; and body > * finds the direct children of the body tag
* siblingA + siblingB: finds sibling B element immediately preceded by sibling A, e.g. div.head + div
* siblingA ~ siblingX: finds sibling X element preceded by sibling A, e.g. h1 ~ p
* el, el, el: group multiple selectors, find unique elements that match any of the selectors; e.g. div.masthead, div.logo
Pseudo selectors
* :lt(n): find elements whose sibling index (i.e. its position in the DOM tree relative to its parent) is less than n; e.g. td:lt(3)
* :gt(n): find elements whose sibling index is greater than n; e.g. div p:gt(2)
* :eq(n): find elements whose sibling index is equal to n; e.g. form input:eq(1)
* :has(seletor): find elements that contain elements matching the selector; e.g. div:has(p)
* :not(selector): find elements that do not match the selector; e.g. div:not(.logo)
* :contains(text): find elements that contain the given text. The search is case-insensitive; e.g. p:contains(jsoup)
* :containsOwn(text): find elements that directly contain the given text
* :matches(regex): find elements whose text matches the specified regular expression; e.g. div:matches((?i)login)
* :matchesOwn(regex): find elements whose own text matches the specified regular expression
* Note that the above indexed pseudo-selectors are 0-based, that is, the first element is at index 0, the second at 1, etc
更多的信息可以参考[http://jsoup.org/|http://jsoup.org/]