使用 xslt 解析复杂的 xml

Question

我尝试解析 xml，但我没有机会，如果有人能解释我该怎么做或解释问题出在哪里，我将不胜感激：

这是我的 xml 代码：

    <?xml version='1.0' encoding='UTF-8'?>
    <nvd xmlns:vuln="http://scap.nist.gov/schema/vulnerability/0.4" xmlns:scap-        core="http://scap.nist.gov/schema/scap-core/0.1" xmlns="http://scap.nist.gov/schema/feed/vulnerability/2.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:cpe-lang="http://cpe.mitre.org/language/2.0" xmlns:patch="http://scap.nist.gov/schema/patch/0.1" xmlns:cvss="http://scap.nist.gov/schema/cvss-v2/0.2" pub_date="2013-01-22T06:34:06" xsi:schemaLocation="http://scap.nist.gov/schema/patch/0.1 http://nvd.nist.gov/schema/patch_0.1.xsd http://scap.nist.gov/schema/scap-core/0.1 http://nvd.nist.gov/schema/scap-core_0.1.xsd http://scap.nist.gov/schema/feed/vulnerability/2.0 http://nvd.nist.gov/schema/nvd-cve-feed_2.0.xsd"         nvd_xml_version="2.0">
      <entry id="CVE-2009-0001">
        <vuln:vulnerable-software-list>
          <vuln:product>cpe:/a:apple:quicktime:3</vuln:product>
          <vuln:product>cpe:/a:apple:quicktime:7.3.1.70</vuln:product>
        </vuln:vulnerable-software-list>
        <vuln:cvss>
          <cvss:base_metrics>
          <cvss:score>9.3</cvss:score>
          <cvss:access-vector>NETWORK</cvss:access-vector>
          <cvss:access-complexity>LOW</cvss:access-complexity>
          <cvss:authentication>NONE</cvss:authentication>

          </cvss:base_metrics>
          </vuln:cvss>
      </entry>
      <entry id="CVE-2009-0002">
        <vuln:vulnerable-software-list>
          <vuln:product>cpe:/a:apple:quicktime:3</vuln:product>
          <vuln:product>cpe:/a:apple:quicktime:6.5</vuln:product>
          <vuln:product>cpe:/a:apple:quicktime:7.0</vuln:product>
          <vuln:product>cpe:/a:apple:quicktime:7.3.1.70</vuln:product>
        </vuln:vulnerable-software-list>
        <vuln:cvss>
          <cvss:base_metrics>
            <cvss:score>3.2</cvss:score>
            <cvss:access-vector>NETWORK</cvss:access-vector>
            <cvss:access-complexity>LOW</cvss:access-complexity>
            <cvss:authentication>NONE</cvss:authentication>

          </cvss:base_metrics>
        </vuln:cvss>
      </entry>
    </nvd>

我在下面的 xsl 文件中使用 xslt：

    <?xml version="1.0" encoding="UTF-8"?>
    <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
                    xmlns:nvd="http://scap.nist.gov/schema/feed/vulnerability/2.0"
                    xmlns:vuln="http://scap.nist.gov/schema/vulnerability/0.4" version="1.0">

    <xsl:output encoding="UTF-8" method="text" />

    <xsl:template match="/"><xsl:apply-templates select="nvd:nvd" /></xsl:template>

    <xsl:template match="nvd:nvd"><xsl:apply-templates select="nvd:entry" /></xsl:template>

    <xsl:template match="nvd:entry">
    <xsl:apply-templates select="vuln:vulnerable-software-list">
      <xsl:with-param name="entryid" select="@id" />
    </xsl:apply-templates>
    </xsl:template>

    <xsl:template match="vuln:vulnerable-software-list">
    <xsl:param name="entryid" />
    <xsl:for-each select="vuln:product">
    <xsl:value-of select="$entryid" />:<xsl:value-of select="text()" /><xsl:text>
    </xsl:text>
    </xsl:for-each>
    </xsl:template>

    </xsl:stylesheet>

结果是：

    # xsltproc a2.xsl a2.xml
    CVE-2009-0001:cpe:/a:apple:quicktime:3
    CVE-2009-0001:cpe:/a:apple:quicktime:7.3.1.70
    CVE-2009-0002:cpe:/a:apple:quicktime:3
    CVE-2009-0002:cpe:/a:apple:quicktime:6.5
    CVE-2009-0002:cpe:/a:apple:quicktime:7.0
    CVE-2009-0002:cpe:/a:apple:quicktime:7.3.1.70

但现在我想像这样添加 cvss:score a 结尾：

    CVE-2009-0001:cpe:/a:apple:quicktime:3@9.3
    CVE-2009-0001:cpe:/a:apple:quicktime:7.3.1.70@9.3
    CVE-2009-0002:cpe:/a:apple:quicktime:3@3.2
    CVE-2009-0002:cpe:/a:apple:quicktime:6.5@3.2
    CVE-2009-0002:cpe:/a:apple:quicktime:7.0@3.2
    CVE-2009-0002:cpe:/a:apple:quicktime:7.3.1.70@3.2

我尝试过这样的想法：

添加

          <xsl:apply-templates select="vuln:cvss/cvss:base_metrics/cvss:score"> 

或

    select="*/score" 

但它不起作用.... :-(

当然我已经添加了一个参数：

      <xsl:value-of select="$score" /><xsl:text>

在模板 vuln:vulnerable-software-list 中

感谢您的帮助

问候

阿诺

---

嗨 Jallopa：我尝试在 for-each 部分添加您的代码，但它返回：

    xsltproc a.xsl a.xml
    XPath error : Undefined namespace prefix
    xmlXPathCompiledEval: evaluation failed
    runtime error: file a.xsl line 21 element value-of
    XPath evaluation returned no result.

第 21 行包含：

    <xsl:value-of select="ancestor::entry[1]/vuln:cvss/cvss:base_metrics/cvss:score"/>

您好 wst，我已经尝试过您的代码，但这次

    xsltproc a.xsl a.xml
    XPath error : Undefined namespace prefix
    xmlXPathCompiledEval: evaluation failed
    runtime error: file a.xsl line 15 element with-param
    Failed to evaluate the expression of variable 'score'. 

第 15 行是：

           <xsl:with-param name="score" select="vuln:cvss/cvss:base_metrics/cvss:score"/>

（我在 with-param 中的选择中添加了 =）

有什么想法吗？

谢谢。

Answer 1

在 foreach 元素中，添加：

<xsl:value-of select="ancestor::entry[1]/vuln:cvss/cvss:base_metrics/cvss:score"/>

这将向上导航到第一个“条目”元素，然后向下导航到 cvss:score。

Answer 2

这个问题可以更简单地解决，但是保持你的模板风格，你可以将值作为另一个参数传递：

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" 
    xmlns:nvd="http://scap.nist.gov/schema/feed/vulnerability/2.0"
    xmlns:vuln="http://scap.nist.gov/schema/vulnerability/0.4" version="1.0">

<xsl:output encoding="UTF-8" method="text" />

<xsl:template match="/"><xsl:apply-templates select="nvd:nvd" /></xsl:template>

<xsl:template match="nvd:nvd"><xsl:apply-templates select="nvd:entry" /></xsl:template>

<xsl:template match="nvd:entry">
    <xsl:apply-templates select="vuln:vulnerable-software-list">
        <xsl:with-param name="entryid" select="@id" />
        <xsl:with-param name="score" select"vuln:cvss/cvss:base_metrics/cvss:score"/>
    </xsl:apply-templates>
</xsl:template>

<xsl:template match="vuln:vulnerable-software-list">
    <xsl:param name="entryid" />
    <xsl:param name="score" />
    <xsl:for-each select="vuln:product">
        <xsl:value-of select="$entryid" />:<xsl:value-of select="text()" />@<xsl:value-of select="$score" /><xsl:text>
    </xsl:text>
    </xsl:for-each>
</xsl:template>

</xsl:stylesheet>