Question

我有以下XML：

<thoughts>
    <thought>
        <id>1</id>
        <category>Leadership</category>
        <what>sometext</what>            
        <who>sometext</who>
    </thought>
    <thought>
        <id>2</id>
        <category>Leadership</category>
        <what>sometext</what>            
        <who>sometext</who>
    </thought>
    ... 100s of category Leadership
    <thought>
        <id>1</id>
        <category>Love</category>
        <what>sometext</what>            
        <who>sometext</who>
    </thought>
    <thought>
        <id>2</id>
        <category>Love</category>
        <what>sometext</what>            
        <who>sometext</who>
    </thought>
    ... 100s of category Love

    ... and so on up to about ten categories
</thoughts>

我想为给定的ID和类别选择思想（什么）。我在Java中这样做。我尝试了以下方法：

"/thought[id='1']/thought[category='Love']/what/text()"

Java：

XPathFactory factory = XPathFactory.newInstance();
XPath xPath = factory.newXPath();
XPathExpression expr1 = xPath.compile("/thought[id='1']/thought[category='Love']/what/text()");
Object result1 = expr1.evaluate(doc, XPathConstants.NODESET);
NodeList nodes1 = (NodeList) result1;

我也尝试过XPathExpressions：

/thoughts/thought[id='1']/thought[category=`Love`]/what/text()

我是XML和XPath的新手。

Answer 1

使用：

/*/thought[id = '1' and category = 'Love']/what

这会选择what个元素的thought元素，该元素具有id子元素，其字符串值为"1"且具有category字符串值为"Love"的子元素，并且thought元素）是XML文档顶部元素的子元素。

如果您需要上面选择的元素的文本节点子节点，请使用：

/*/thought[id = '1' and category = 'Love']/what/text()

如果您只需要上述文本节点（第一个）的字符串值，请使用：

string(/*/thought[id = '1' and category = 'Love']/what)

基于XSLT的验证：

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"> <xsl:output omit-xml-declaration="yes" indent="yes"/> <xsl:strip-space elements="*"/> <xsl:template match="/"> <xsl:copy-of select="/*/thought[id = '1' and category = 'Love']/what"/> ============ <xsl:copy-of select="/*/thought[id = '1' and category = 'Love']/what/text()"/> ============ <xsl:copy-of select="string(/*/thought[id = '1' and category = 'Love']/what)"/> </xsl:template> </xsl:stylesheet>

将此转换应用于以下XML文档（提供的文档具有所需节点的不同值）：

<thoughts> <thought> <id>1</id> <category>Leadership</category> <what>sometext</what> <who>sometext</who> </thought> <thought> <id>2</id> <category>Leadership</category> <what>sometext</what> <who>sometext</who> </thought> ... 100's of with category Leadership <thought> <id>1</id> <category>Love</category> <what>some Love text 1</what> <who>sometext</who> </thought> <thought> <id>2</id> <category>Love</category> <what>sometext</what> <who>sometext</who> </thought> ... 100's of with category Love ... and so on up to about ten categories </thoughts>

评估三个XPath表达式，并将这些评估的结果复制到输出，由一个方便的分隔符直观地分开：

<what>some Love text 1</what> ============ some Love text 1 ============ some Love text 1

<强>更新：

在评论中，OP已添加了一项要求，即不仅应选择what，还应选择who。

以下是此案例的相应新XPath表达式：

/*/thought[id = '1' and category = 'Love']/*[self::what or self::who] /*/thought[id = '1' and category = 'Love']/*[self::what or self::who]/text()

Answer 2

我建议遵循XPath xpression：

/thoughts/thought[id='1' and category='Love']/what/text()

我可以推荐这个tutorial

XPath表达式无法正常运行

2 个答案: