jsoup|jsoup中选择器select()的使用（jquery,css选择器风格） jsoup|java

没用过Jquery和css的选择器，所以看了Jsoup的介绍后还是不会用select选择器，然后去看了下Jquery选择器的使用，才发觉jsoup真心强大，所以做个简单记录。
选择器简介：
选择器既可以作为元素选择器也可以作为属性选择器，允许您通过标签名、属性名或内容对 HTML 元素进行选择。
选择器允许您对 HTML 元素组或单个元素进行操作。
在 HTML DOM 术语中：选择器允许您对 DOM 元素组或单个 DOM 节点进行操作。
元素选择器： select("p") 选取元素。
【jsoup|jsoup中选择器select()的使用（jquery,css选择器风格）】 select("p.intro") 选取所有 class="intro" 的元素。
select("p#demo") 选取 id="demo" 的第一个元素。

属性选择器： select("[href]") 选取所有带有 href 属性的元素。
select("[href='https://www.it610.com/article/#']") 选取所有带有 href 值等于 "#" 的元素。
select("[href!='#']") 选取所有带有 href 值不等于 "#" 的元素。
select("[href$='.jpg']") 选取所有 href 值以 ".jpg" 结尾的元素。

更多的选择器实例：

语法	描述
$(this)	当前 HTML 元素
$("p")	所有元素
$("p.intro")	所有 class="intro" 的元素
$(".intro")	所有 class="intro" 的元素
$("#intro")	id="intro" 的第一个元素
$("ul li:first")	每个的第一个元素
$("[href$='.jpg']")	所有带有以 ".jpg" 结尾的属性值的 href 属性
$("div#intro .head")	id="intro" 的元素中的所有 class="head" 的元素

更多的使用方法可以参考Jquery选择器参考手册：http://www.w3school.com.cn/jquery/jquery_ref_selectors.asp 参考：http://www.w3school.com.cn/jquery/jquery_selectors.asp http://jsoup.org/cookbook/extracting-data/selector-syntax

Description jsoup elements support a CSS (or jquery) like selector syntax to find matching elements, that allows very powerful and robust queries.
The select method is available in a Document, Element, or in Elements. It is contextual, so you can filter by selecting from a specific element, or by chaining select calls.
Select returns a list of Elements (as Elements), which provides a range of methods to extract and manipulate the results.
Selector overview

tagname: find elements by tag, e.g. a
ns|tag: find elements by tag in a namespace, e.g. fb|name finds 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 > pfinds 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