用XPath处理XML时遇到的选取节点的方法

Here are some examples of location paths using abbreviated syntax:

para

selects the

para

element children of the context node

*

selects all element children of the context node

text()

selects all text node children of the context node

@name

selects the

name

attribute of the context node

@*

selects all the attributes of the context node

para[1]

selects the first

para

child of the context node

para[last()]

selects the last

para

child of the context node

*/para

selects all

para

grandchildren of the context node

/doc/chapter[5]/section[2]

selects the second

section

of the fifth

chapter

of the

doc

chapter//para

selects the

para

element descendants of the

chapter

element children of the context node

//para

selects all the

para

descendants of the document root and thus selects all

para

elements in the same document as the context node

//olist/item

selects all the

item

elements in the same document as the context node that have an

olist

parent

.

selects the context node

.//para

selects the

para

element descendants of the context node

..

selects the parent of the context node

../@lang

selects the

lang

attribute of the parent of the context node

para[@type="warning"]

selects all

para

children of the context node that have a

type

attribute with value

warning

para[@type="warning"][5]

selects the fifth

para

child of the context node that has a

type

attribute with value

warning

para[5][@type="warning"]

selects the fifth

para

child of the context node if that child has a

type

attribute with value

warning

chapter[title="Introduction"]

selects the

chapter

children of the context node that have one or more

title

children with string-value equal to

Introduction

chapter[title]

selects the

chapter

children of the context node that have one or more

title

children

employee[@secretary and @assistant]

selects all the

employee

children of the context node that have both a

secretary

attribute and an

assistant

attribute