这期内容当中小编将会给大家带来有关怎么进行JSOUP 爬虫的分析，文章内容丰富且以专业的角度为大家分析和叙述，阅读完这篇文章希望大家可以有所收获。
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规则编写说明文档
通用选择器（*）是隐含在没有元素选择器提供 (i.e. *.header and .header is equivalent).
| 样式 | 匹配 | 例子 | |
|---|---|---|---|
* | 任何元素 | * | |
tag | 通过Tga标签获取元素 | div | |
ns|E | elements of type E in the namespace ns | fb|name finds | |
#id | elements with attribute ID of "id" | div#wrap, #logo | |
.class | elements with a class name of "class" | div.left, .result | |
[attr] | elements with an attribute named "attr" (with any value) | a[href], [title] | |
[^attrPrefix] | elements with an attribute name starting with "attrPrefix". Use to find elements with HTML5 datasets | [^data-], div[^data-] | |
[attr=val] | elements with an attribute named "attr", and value equal to "val" | img[width=500], a[rel=nofollow] | |
[attr="val"] | elements with an attribute named "attr", and value equal to "val" | span[hello="Cleveland"][goodbye="Columbus"], a[rel="nofollow"] | |
[attr^=valPrefix] | elements with an attribute named "attr", and value starting with "valPrefix" | a[href^=http:] | |
[attr$=valSuffix] | elements with an attribute named "attr", and value ending with "valSuffix" | img[src$=.png] | |
[attr*=valContaining] | elements with an attribute named "attr", and value containing "valContaining" | a[href*=/search/] | |
[attr~=regex] | elements with an attribute named "attr", and value matching the regular expression | img[src~=(?i)\\.(png|jpe?g)] | |
| The above may be combined in any order | div.header[title] | ||
组合器 | |||
E F | an F element descended from an E element | div a, .logo h2 | |
E > F | an F direct child of E | ol > li | |
E + F | an F element immediately preceded by sibling E | li + li, div.head + div | |
E ~ F | an F element preceded by sibling E | h2 ~ p | |
E, F, G | all matching elements E, F, or G | a[href], div, h4 | |
伪选择器 | |||
:lt(n) | elements whose sibling index is less than n | td:lt(3) finds the first 3 cells of each row | |
:gt(n) | elements whose sibling index is greater than n | td:gt(1) finds cells after skipping the first two | |
:eq(n) | elements whose sibling index is equal to n | td:eq(0) finds the first cell of each row | |
:has(selector) | elements that contains at least one element matching the selector | div:has(p) finds divs that contain p elements | |
:not(selector) | elements that do not match the selector. See also Elements.not(String) | div:not(.logo) finds all divs that do not have the "logo" class.
| |
:contains(text) | elements that contains the specified text. The search is case insensitive. The text may appear in the found element, or any of its descendants. | p:contains(jsoup) finds p elements containing the text "jsoup". | |
:matches(regex) | elements whose text matches the specified regular expression. The text may appear in the found element, or any of its descendants. | td:matches(\\d+) finds table cells containing digits. div:matches((?i)login) finds divs containing the text, case insensitively. | |
:containsOwn(text) | elements that directly contain the specified text. The search is case insensitive. The text must appear in the found element, not any of its descendants. | p:containsOwn(jsoup) finds p elements with own text "jsoup". | |
:matchesOwn(regex) | elements whose own text matches the specified regular expression. The text must appear in the found element, not any of its descendants. | td:matchesOwn(\\d+) finds table cells directly containing digits. div:matchesOwn((?i)login) finds divs containing the text, case insensitively. | |
| The above may be combined in any order and with other selectors | .light:contains(name):eq(0) | ||
结构伪选择器 | |||
:root | The element that is the root of the document. In HTML, this is the html element | :root | |
:nth-child(an+b) | elements that have :nth-child() can take odd and even as arguments instead. odd has the same signification as 2n+1, and even has the same signification as 2n. | tr:nth-child(2n+1) finds every odd row of a table. :nth-child(10n-1) the 9th, 19th, 29th, etc, element. li:nth-child(5) the 5h li | |
:nth-last-child(an+b) | elements that have an+b-1 siblings afterit in the document tree. Otherwise like :nth-child() | tr:nth-last-child(-n+2) the last two rows of a table | |
:nth-of-type(an+b) | pseudo-class notation represents an element that has an+b-1 siblings with the same expanded element name before it in the document tree, for any zero or positive integer value of n, and has a parent element | img:nth-of-type(2n+1) | |
:nth-last-of-type(an+b) | pseudo-class notation represents an element that has an+b-1 siblings with the same expanded element name after it in the document tree, for any zero or positive integer value of n, and has a parent element | img:nth-last-of-type(2n+1) | |
:first-child | elements that are the first child of some other element. | div > p:first-child | |
:last-child | elements that are the last child of some other element. | ol > li:last-child | |
:first-of-type | elements that are the first sibling of its type in the list of children of its parent element | dl dt:first-of-type | |
:last-of-type | elements that are the last sibling of its type in the list of children of its parent element | tr > td:last-of-type | |
:only-child | elements that have a parent element and whose parent element hasve no other element children | ||
:only-of-type | an element that has a parent element and whose parent element has no other element children with the same expanded element name | ||
:empty | elements that have no children at all |
上述就是小编为大家分享的怎么进行JSOUP 爬虫的分析了，如果刚好有类似的疑惑，不妨参照上述分析进行理解。如果想知道更多相关知识，欢迎关注创新互联行业资讯频道。
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