Question

在iReport文档中，我发现了这些XPath查询：

/addressbook/category@name
/addressbook/category/person@id
/addressbook/category/person+LASTNAME
/addressbook/category/person+FIRSTNAME
/addressbook/category/person+hobbies*hobby

我的问题：

category@name与category/@name相同吗？
person+LASTNAME的含义是什么？（确切地说 + ）
person+hobbies*hobby的含义是什么（确切地说 * ）

它们适用于此XML：

<addressbook>
 <category name="home">
    <person id="1">                                                           
      <LASTNAME>Davolio</LASTNAME>
      <FIRSTNAME>Nancy</FIRSTNAME>
      <hobbies>
        <hobby>Radio Control</hobby>
        <hobby>R/C Cars</hobby>
        <hobby>Micro R/C Cars</hobby>
        <hobby>Die-Cast Models</hobby>
      </hobbies>
      <email>email1@my.domain.it</email>
      <email>email2@my.domain2.it</email> 
     ...

（完整XML here）

Answer 1

那不是XPath。它就像XPath一样。从您链接的页面：

<symbol>用于向基本路径添加额外路径并定义应返回的内容   +将以下路径添加到base_path（这在base_path =记录路径时发生）;
  @返回属性值：后跟属性名称;
  *将以下路径标识的所有标记返回为JRXMLDatasource

它在section 7.3 of the link you have in your question。

所以，从那里开始，这些就是你的类XPath表达式的含义：

/addressbook/category@name
  The basepath is /addressbook/category, return the attribute "name"

/addressbook/category/person@id
  The basepath is /addressbook/category/person, return the attribute "id"

/addressbook/category/person+LASTNAME
  The basepath is /addressbook/category/person, return the element "LASTNAME"

/addressbook/category/person+FIRSTNAME
  The basepath is /addressbook/category/person, return the element "FIRSTNAME"

/addressbook/category/person+hobbies*hobby
  The basepath is /addressbook/category/person, look inside "hobbies"
  and return all elements named "hobby"

“+”，“@”和“*”在XPath查询中的含义是什么？

1 个答案: