Running custom Java functions within XSLT and SAXO

问题:

Meta

• Saxon XSLT processor (v. 9.1.8)
• Java
• XSLT 2.0

I got a simple example of a java class file and some xsl transformation. My goal is to run my custom java functions from the class file within the XSLT process (via SAXON). How is this possible? When I start the below described batch file the cmd displays an error calling me the function is not known to saxon. So I have to add my class to the Java / or Saxon CLASSPATH?

The transformation should copy all XML data and (return &) display the dimension of imagefiles.

My XSL Transformation

<xsl:stylesheet
xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:ImageInfo="java:ImageInfo"
version="2.0">

<xsl:output method="xml"/>
<xsl:template match="@* | node()">
    <xsl:copy>
        <xsl:apply-templates select="@* | node()"/>
    </xsl:copy>
<xsl:template/>

<xsl:template match="img">
    <xsl:copy>
        [image] file found: <xsl:value-of select="ImageInfo:getImageWidth(@src)"/> x <xsl:value-of select="ImageInfo:getImageHeight(@src)"/>
    </xsl:copy>
</xsl:template>

Java Class

import javax.swing.ImageIcon;
public class ImageInfo {

String filename;
ImageIcon img;

public ImageInfo(String filename) {
    this.filename = filename;
    img = new ImageIcon(filename);
}

public int getWidth() {
    return img.getIconWidth();
}

public int getHeight() {
    return img.getIconHeight();
}
}

Saxon command line call (via .BAT)

java -jar "%~dp0\saxonb9-1-0-8j\saxon9.jar" -s:"data.xml" -xsl:"transformation.xsl" -o:"result.xml"

回答1:

You need the -cp option of your java command e.g. java -cp ".;%~dp0\saxonb9-1-0-8j\saxon9.jar" net.sf.saxon.Transform -s:"data.xml" -xsl:"transformation.xsl" -o:"result.xml" where you need to make sure that the directory with your ImageInfo is on the class path, I have added ., assuming the class is in your current working directory.

However, note that ImageInfo:getImageWidth(@src) would try to call a static method getImageWidth, you have instance methods, the method you have is called getWidth and it does not take an argument.

See the documentation for that old version of Saxon 9, it should be available on http://saxon.sourceforge.net/.

回答2:

Once you've sorted out your classpath problems as Martin suggests, the code you want will be something like this:

<xsl:variable name="image" select="ImageInfo:new(@src)"/>
[image] file found: 
   <xsl:value-of select="ImageInfo:getWidth($image)"/> x 
   <xsl:value-of select="ImageInfo:getHeight($image)"/>