1
我难以理解为什么下面的示例程序拒绝正确应用我的样式表。看来Xalan 2.7.1中的dyn:evaluate拒绝处理某些XPath变量。dyn：评估已知在Xalan-J 2.7.1中有问题的扩展函数吗？
与类路径xalan-j运行下面的程序产生了以下结果：
package com.testing2.xslt;
import java.io.*;
import java.util.logging.*;
import javax.xml.transform.*;
import javax.xml.transform.stream.*;
public class DynEvaluateTransform {
private static final String XSLT = "" +
"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n" +
"<xsl:stylesheet xmlns:xsl=\"http://www.w3.org/1999/XSL/Transform\"\n" +
" xmlns:det=\"org:example:DynEvaluateTransform\"\n" +
" xmlns:dyn=\"http://exslt.org/dynamic\"\n" +
" extension-element-prefixes=\"dyn\"\n" +
" version=\"1.0\">\n" +
" \n" +
" <xsl:variable name=\"input-doc\" select=\"document('input.xml', /)\" />\n" +
" <xsl:variable name=\"selections\" select=\"$input-doc/det:selections\" />\n" +
" \n" +
" <xsl:template match=\"/\">\n" +
" <xsl:choose>\n" +
" <xsl:when test=\"function-available('dyn:evaluate')\">\n" +
" <xsl:message>dyn:evaluate available</xsl:message>\n" +
" </xsl:when>\n" +
" <xsl:otherwise>\n" +
" <xsl:message>dyn:evaluate not available</xsl:message>\n" +
" </xsl:otherwise>\n" +
" </xsl:choose>\n" +
" <xsl:message>input.xml content:</xsl:message>\n" +
" <xsl:for-each select=\"$selections/*\">\n" +
" <xsl:message>{<xsl:value-of select=\"namespace-uri()\"/>}<xsl:value-of select=\"local-name()\"/></xsl:message>\n" +
" </xsl:for-each> \n" +
" <xsl:for-each select=\"//@condition\">\n" +
" <xsl:message><xsl:value-of select=\".\"/></xsl:message>\n" +
" <xsl:message><xsl:value-of select=\"string(dyn:evaluate(string(.)))\"/></xsl:message>\n" +
" </xsl:for-each>\n" +
" </xsl:template>\n" +
" \n" +
"</xsl:stylesheet>";
private static final String EXAMPLE = "" +
"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n" +
"<foos xmlns=\"org:example:DynEvaluateTransform\"> \n" +
" <foo condition=\"true()\" /> \n" +
" <foo condition=\"false()\" /> \n" +
" <foo condition=\"false() or true()\" />\n" +
" <foo condition=\"$selections\" />\n" +
" <foo condition=\"$selections/*\" />\n" +
" <foo condition=\"$selections/*[local-name()='a']\" />\n" +
" <foo condition=\"$selections/element::node()[local-name()='a']\" />\n" +
" <foo condition=\"local-name($selections/*)\" />\n" +
" <foo condition=\"not($selections/*[local-name()='a' and namespace-uri()='org:example:foo'])\" />\n" +
" <foo condition=\"$selections/*[local-name()='b' and namespace-uri()='org:example:foo']\" />\n" +
" <foo condition=\"$selections/*[local-name()='c' and namespace-uri()='org:example:foo']\" />\n" +
" <foo condition=\"not($selections/*[local-name()='a' and namespace-uri()='org:example:foo']) or ($selections/*[local-name()='b' and namespace-uri()='org:example:foo'] and $selections/*[local-name()='c' and namespace-uri()='org:example:foo'])\" />\n" +
"</foos>";
private static final String INPUT = "" +
"<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n" +
"<selections xmlns=\"org:example:DynEvaluateTransform\">\n" +
" <a xmlns=\"org:example:foo\"/>\n" +
" <b xmlns=\"org:example:foo\"/>\n" +
" <c xmlns=\"org:example:foo\"/>\n" +
"</selections>";
private TransformerFactory xalanTransFact;
public DynEvaluateTransform() {
xalanTransFact = new org.apache.xalan.processor.TransformerFactoryImpl();
xalanTransFact.setURIResolver(new Resolver());
}
private void applyTransform() {
// XSLT(EXAMPLE) --> output.xml
// ^
// |
// INPUT
OutputStreamWriter writer = null;
try {
String outputFileName = DynEvaluateTransform.getLocalFileName("output.xml");
File file = new File(outputFileName);
writer = new OutputStreamWriter(new FileOutputStream(file), "UTF-8");
System.out.println(org.apache.xalan.Version.getVersion());
Transformer transformer = xalanTransFact.newTransformer(new StreamSource(new StringReader(XSLT)));
transformer.setOutputProperty(OutputKeys.INDENT, "yes");
transformer.setOutputProperty(OutputKeys.METHOD, "xml");
transformer.setOutputProperty(OutputKeys.ENCODING, "utf-8");
transformer.transform(
new StreamSource(new StringReader(EXAMPLE)),
new StreamResult(writer));
} catch (UnsupportedEncodingException ex) {
Logger.getLogger(DynEvaluateTransform.class.getName()).log(Level.SEVERE, null, ex);
} catch (FileNotFoundException ex) {
Logger.getLogger(DynEvaluateTransform.class.getName()).log(Level.SEVERE, null, ex);
} catch (TransformerConfigurationException ex) {
Logger.getLogger(DynEvaluateTransform.class.getName()).log(Level.SEVERE, null, ex);
} catch (TransformerException ex) {
Logger.getLogger(DynEvaluateTransform.class.getName()).log(Level.SEVERE, null, ex);
} finally {
if (writer != null) {
try {
writer.close();
} catch (IOException ex) {
}
}
}
}
private void rebuildInput() {
// ignore - this just writes the input.xml file, so we can later reference it
StringReader strReader = null;
OutputStreamWriter fileWriter = null;
try {
String fileName = getLocalFileName("input.xml");
strReader = new StringReader(INPUT);
File file = new File(fileName);
fileWriter = new OutputStreamWriter(new FileOutputStream(file), "UTF-8");
TransformerFactory factory = TransformerFactory.newInstance();
Transformer transformer = factory.newTransformer();
transformer.setOutputProperty(OutputKeys.INDENT, "yes");
transformer.setOutputProperty(OutputKeys.METHOD, "xml");
transformer.transform(
new StreamSource(strReader),
new StreamResult(fileWriter));
} catch (UnsupportedEncodingException ex) {
Logger.getLogger(DynEvaluateTransform.class.getName()).log(Level.SEVERE, null, ex);
} catch (FileNotFoundException ex) {
Logger.getLogger(DynEvaluateTransform.class.getName()).log(Level.SEVERE, null, ex);
} catch (TransformerConfigurationException ex) {
Logger.getLogger(DynEvaluateTransform.class.getName()).log(Level.SEVERE, null, ex);
} catch (TransformerException ex) {
Logger.getLogger(DynEvaluateTransform.class.getName()).log(Level.SEVERE, null, ex);
} catch (IOException ex) {
Logger.getLogger(DynEvaluateTransform.class.getName()).log(Level.SEVERE, null, ex);
} finally {
if (strReader != null) {
strReader.close();
}
if (fileWriter != null) {
try {
fileWriter.close();
} catch (IOException ex) {
}
}
}
}
public static void main(String[] args) {
DynEvaluateTransform det = new DynEvaluateTransform();
det.rebuildInput();
det.applyTransform();
}
private static String getLocalFileName(String href) {
String name = System.getProperty("user.dir");
if (!name.endsWith(File.separator)) {
name += File.separator;
}
name += href;
return name;
}
private static class Resolver implements URIResolver {
@Override
public Source resolve(String href, String base) throws TransformerException {
if ("input.xml".equals(href)) {
return new StreamSource(new File(DynEvaluateTransform.getLocalFileName(href)));
} else {
return null;
}
}
}
}
Xalan Java 2.7.1
SystemId Unknown; Line #14; Column #30; dyn:evaluate available
SystemId Unknown; Line #20; Column #22; input.xml content:
SystemId Unknown; Line #22; Column #26; {org:example:foo}a
SystemId Unknown; Line #22; Column #26; {org:example:foo}b
SystemId Unknown; Line #22; Column #26; {org:example:foo}c
SystemId Unknown; Line #25; Column #26; true()
SystemId Unknown; Line #26; Column #26; true
SystemId Unknown; Line #25; Column #26; false()
SystemId Unknown; Line #26; Column #26; false
SystemId Unknown; Line #25; Column #26; false() or true()
SystemId Unknown; Line #26; Column #26; true
SystemId Unknown; Line #25; Column #26; $selections
SystemId Unknown; Line #26; Column #26;
SystemId Unknown; Line #25; Column #26; $selections/*
SystemId Unknown; Line #26; Column #26;
SystemId Unknown; Line #25; Column #26; $selections/*[local-name()='a']
SystemId Unknown; Line #26; Column #26;
SystemId Unknown; Line #25; Column #26; $selections/element::node()[local-name()='a']
SystemId Unknown; Line #26; Column #26;
SystemId Unknown; Line #25; Column #26; local-name($selections/*)
SystemId Unknown; Line #26; Column #26;
SystemId Unknown; Line #25; Column #26; not($selections/*[local-name()='a' and namespace-uri()='org:example:foo'])
SystemId Unknown; Line #26; Column #26; true
SystemId Unknown; Line #25; Column #26; $selections/*[local-name()='b' and namespace-uri()='org:example:foo']
SystemId Unknown; Line #26; Column #26;
SystemId Unknown; Line #25; Column #26; $selections/*[local-name()='c' and namespace-uri()='org:example:foo']
SystemId Unknown; Line #26; Column #26;
SystemId Unknown; Line #25; Column #26; not($selections/*[local-name()='a' and namespace-uri()='org:example:foo']) or ($selections/*[local-name()='b' and namespace-uri()='org:example:foo'] and $selections/*[local-name()='c' and namespace-uri()='org:example:foo'])
SystemId Unknown; Line #26; Column #26; true
示例程序变换的示例输入（实施例）使用所提供的转换（XSLT），其接收输入文件（INPUT，input.xml），通过document()函数打开，作为“参数”。此输入文件包含一组使用XPath表达式进行测试的元素（位于示例中）。
该程序的输出表明支持dyn:evaluate函数，正确读取input.xml，即简单的XPath表达式得到正确评估，但只要涉及XPath变量，它就会中断。
下面涉及的所有文档的可读版本。
的input.xml
<?xml version="1.0" encoding="UTF-8"?>
<selections xmlns="org:example:DynEvaluateTransform">
<a xmlns="org:example:foo"/>
<b xmlns="org:example:foo"/>
<c xmlns="org:example:foo"/>
</selections>
例
<?xml version="1.0" encoding="UTF-8"?>
<foos xmlns="org:example:DynEvaluateTransform">
<foo condition="true()" />
<foo condition="false()" />
<foo condition="false() or true()" />
<foo condition="$selections" />
<foo condition="$selections/*" />
<foo condition="$selections/*[local-name()='a']" />
<foo condition="$selections/element::node()[local-name()='a']" />
<foo condition="local-name($selections/*)" />
<foo condition="not($selections/*[local-name()='a' and namespace-uri()='org:example:foo'])" />
<foo condition="$selections/*[local-name()='b' and namespace-uri()='org:example:foo']" />
<foo condition="$selections/*[local-name()='c' and namespace-uri()='org:example:foo']" />
<foo condition="not($selections/*[local-name()='a' and namespace-uri()='org:example:foo']) or ($selections/*[local-name()='b' and namespace-uri()='org:example:foo'] and $selections/*[local-name()='c' and namespace-uri()='org:example:foo'])" />
</foos>
XSLT
<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:det="org:example:DynEvaluateTransform"
xmlns:dyn="http://exslt.org/dynamic"
extension-element-prefixes="dyn"
version="1.0">
<xsl:variable name="input-doc" select="document('input.xml', /)" />
<xsl:variable name="selections" select="$input-doc/det:selections" />
<xsl:template match="/">
<xsl:choose>
<xsl:when test="function-available('dyn:evaluate')">
<xsl:message>dyn:evaluate available</xsl:message>
</xsl:when>
<xsl:otherwise>
<xsl:message>dyn:evaluate not available</xsl:message>
</xsl:otherwise>
</xsl:choose>
<xsl:message>input.xml content:</xsl:message>
<xsl:for-each select="$selections/*">
<xsl:message>{<xsl:value-of select="namespace-uri()"/>}<xsl:value-of select="local-name()"/></xsl:message>
</xsl:for-each>
<xsl:for-each select="//@condition">
<xsl:message><xsl:value-of select="."/></xsl:message>
<xsl:message><xsl:value-of select="string(dyn:evaluate(string(.)))"/></xsl:message>
</xsl:for-each>
</xsl:template>
</xsl:stylesheet>
不Xalan的不支持在dyn:evaluate参数的XPath变量？我是否正确定义了表达式？尝试在选定Xalan的情况下在oXygen中运行此样式表时，首次遇到XPath变量时报告java.lang.RuntimeException: ElemTemplateElement error: Function not supported!。
编辑：
我已经为了澄清我的实际问题是什么重写的问题。
你的问题很混乱。您可以使用'function-available（）'函数测试您的处理器是否支持函数。如果支持该功能，并且您获得的结果与您期望的结果不同，请发布可重复的示例。 –
@ michael，这是一个可重复的例子。只需在classpath中使用xalan-j运行代码即可。评估函数受支持，函数可用返回True。但是，它不正确地评估表达式。请让我知道我可以如何清除你的困惑。 – predi
如果使用'org.apache.xalan.xsltc.trax.TransformerFactoryImpl'而不是'org.apache.xalan.processor.TransformerFactoryImpl'，会发生什么？ Xalan有两个XSLT 1.0实现，所以oXygen可能使用xsltc处理器。 –