java - 将节点名称作为参数从 java 代码传递给 .xsl 文件，以从与其节点名称对应的 .xml 文件获取值

Question

我编写了java代码来获取元数据，即从.xsd文件中获取子节点，并将该元数据作为参数传递给.xsl文件，以便根据.xml文件中的对应名称获取值，最后生成.csv格式的输出

XML文档

<personal>
    <details>
        <name>John</name>
        <age>50</age>
        <country>USA</country>
    </details>
    <details>
        <name>Jams</name>
        <age>40</age>
        <country>UK</country>
    </details>
</personal>

** 它的 xsd**

<xs:element minOccurs="0" maxOccurs="unbounded" name="details">
      <xs:complexType>
        <xs:sequence>
          <xs:element minOccurs="0" name="name" type="xs:string" />
          <xs:element minOccurs="0" name="age" type="xs:string" />
          <xs:element minOccurs="0" name="country" type="xs:string" />
          </xs:sequence>
      </xs:complexType>
    </xs:element>

XSLT 样式表

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:param name="Elements"/>
    <xsl:template match="/">
        <xsl:for-each select="//details">
            <xsl:value-of select="$Elements"/>
            <xsl:value-of select="'&#xA;'"/>
        </xsl:for-each>
    </xsl:template>
</xsl:stylesheet>

Java代码

public static void main(String args[]) 抛出异常 {

    //Read the XML data file and code of stylesheet
    File stylesheet = new File("src/style.xsl");
    File xmlSource = new File("src/data.xml");

    //It enables appln to obtain parser to produces DOM object from XML documents
    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
    DocumentBuilder builder = factory.newDocumentBuilder();
    Document document = builder.parse(xmlSource);

    Document doc = builder.parse (new File("src/structure.xsd")); 
    NodeList list = doc.getElementsByTagName("xs:element"); 

    String cols="";
    //loop to print data
    for(int i = 0 ; i < list.getLength(); i++){
        Element first = (Element)list.item(i);      
        if(first.hasAttributes() && first.getAttributeNode("type") != null){
            String nm = first.getAttribute("name"); 
            cols=cols+nm+",";
        }
    }
    cols=cols.substring(0, cols.length()-1);
    System.out.println(cols);

    //It process XML data into required format by reading .xsl file.
    StreamSource stylesource = new StreamSource(stylesheet);
    Transformer transformer = TransformerFactory.newInstance().newTransformer(stylesource);

    transformer.setParameter("Elements", cols);

    //Object that implements this interface contains the information needed to act as source input (XML source or transformation instructions).
    Source source = new DOMSource(document);

    //Directory in which file need to be save after transformation from xml to csv
    Result outputTarget = new StreamResult(new File("C:/Users/Desktop/a.csv"));

    //Transforming
    transformer.transform(source, outputTarget);
}

实际输出

我得到的 .csv 输出为

name,age,country
name,age,country

预期输出为

John,50,USA
Jams,40,UK

Answer 1

使用此转换(我已为全局参数 $Elements 指定了默认值，但每次从 Java 代码调用转换时都会覆盖该值):

<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:output method="text"/>
  <xsl:strip-space elements="*"/>
    <xsl:param name="Elements" select="'name,age,country'"/>

    <xsl:template match="details">
        <xsl:apply-templates select="
        *[contains(concat(',',$Elements,','),
                   concat(',',name(),',')
                   )]"/>
        <xsl:value-of select="'&#xA;'"/>
    </xsl:template>

    <xsl:template match="details/*">
      <xsl:if test="not(position()=1)">,</xsl:if>
      <xsl:value-of select="."/>
    </xsl:template>
</xsl:stylesheet>

当此转换应用于提供的 XML 文档时:

<personal>
    <details>
        <name>John</name>
        <age>50</age>
        <country>USA</country>
    </details>
    <details>
        <name>Jams</name>
        <age>40</age>
        <country>UK</country>
    </details>
</personal>

产生了想要的正确结果:

John,50,USA
Jams,40,UK